The enhanced coating effect of carbonyl iron particles and improved dispersion stability of magnetorheological fluid

The enhanced coating effect of carbonyl iron particles and improved dispersion stability of magnetorheological fluid | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article The enhanced coating effect of carbonyl iron particles and improved dispersion stability of magnetorheological fluid Jie Zhang, Fang Chen, Qinkui Guo, Yuchen Liu, Xiaobing Liu, Shengnan Yan, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4052080/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The coating effect of 1,2-bis(triethoxy-silyl)ethane (BTES) on the carbonyl iron particles (CIP) was enhanced through the etching of CIP by adjusting the concentration of hydrochloric acid (HCl), leading to a significant improvement in the dispersion stability of the magnetorheological fluid (MRF). The microstructures, coating effect and magnetism of the CIPs were examined using the scanning electron microscopy (SEM), automatic surface and porosity analyzer (BTE), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). Furthermore, the rheological properties and dispersion stability of the MRFs were assessed using a rotating rheometer and turbiscan-tower. The results shown that with the concentration of HCl increased, the nanopores appeared on the CIPs and then disappeared, and the specific surface area of the particles increased and then decreased. The number of nanopores sharply increased and the specific surface area of particles sharply increased to 37.7697 m 2 /g when the concentration of HCl reached to 0.50 mol/L. As the concentration of HCl increased, the coated mass of BTES on the particles increased. The coated mass loss was less than 1 wt.% when the concentration of HCl was below 0.50 mol/L, and the coated mass loss increased to 2.45 wt.% when the concentration of HCl was 0.5 mol/L, the coated mass was effectively enhanced by the HCl of higher concentration. As the concentration of HCl increased, the saturation magnetization of particles decreased, and a sharply decrease appeared when the concentration of HCl was 0.50 mol/L, the saturation magnetization of coated particles further decreased from 196.7 emu/g to 113.3 emu/g. As the coated mass of particles increased, the viscosity and shear stress of MRFs increased and the increase was significant when the coated mass loss of particles above 2.45 wt.% without a magnetic field, while which decreased under a magnetic filed. As the coated mass of particles increased, the sedimentation rate of particles decreased from 0.13 to 0.01 mm/h, when the coated mass loss of particles was more than 2.45 wt.%, the sedimentation rate of all MRFs were close to 0.01 mm/h. The coating effect was greatly enhanced by controlling the concentration of HCl, and thus the MRF with superior shear stress and excellent dispersion stability was obtained. Physical sciences/Chemistry/Materials chemistry Physical sciences/Chemistry/Materials chemistry/Magnetic materials Enhancement of coating effect Carbonyl iron particle Etching by hydrochloric acid Magnetorheological fluid Dispersion stability Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Introduction Magnetorheological fluid (MRF) is kind of intelligent material that its rheological properties transforms with changing the external magnetic field. The components of MRF mainly are micron sized magnetic particles, carrier medium and additives. without a magnetic field, the magnetic particles are randomly dispersed in the carrier medium, showing the characteristics of a free flowing Newtonian fluid; under a magnetic field, chain structures are arranged along the magnetic field direction, and the chain structures become thicker with the increase of the magnetic field strength, showing the characteristics of a solid-like pseudoplastic fluid. 1–3 Due to the special rheological properties of MRF, it is widely used in buildings, cars, seals, medicals and other fields. 4–7 Micron-sized CIPs are favored in MRF for their high saturation magnetization, excellent paramagnetic characteristics, optimal size and easy accessibility, thus they are typically utilized as magnetic particles in MRF. However, the MRF faces a significant challenge of severe sedimentation, attributing to the obvious density difference between CIP (7.8 g/cm³) and the carrier medium (e.g., silicone oil at 0.963 g/cm³), and this sedimentation adversely impacts the rheological properties of the MRF, results in the unbalanced distribution of yield stress in MRF. 8–9 Thus, a number of strategies have been used to reduce the sedimentation, such as the use of rod-shaped magnetic particles, 10 the addition of graphene oxide, 11 the addition of fumed silica, 12 the use of high viscosity fluid as carrier medium, 13–14 and the coat of particles with polymer. 15 Of which, it had been reported that the CIP was coated with polystyrene foam, and the sedimentation rate of the MRF decreased from 80–30% compared with the MRF prepared by pure CIP. 16 The CIP was coated with poly(methyl methacrylate) (PMMA) by emulsion polymerization which reduced the density of particles and the sedimentation rate of the MRF decreased from 80–70% compared with the MRF prepared by CIP. 17 The CIP was coated with tragacanth gum, and the sedimentation rate of the MRF decreased from 15–10% compared with the MRF prepared by pure CIP. 18 The coating of the CIP with polymers could improve the dispersion stability of MRF. 19–20 To enhance the coating effect, Belyavskiiet al. reported that the particles were coated with silane coupling agents of different chain lengths, indicated that short chain molecules could increase their graft density on the particles. 21 The number of grafted functional groups of the coated molecules will also affect the coating effect, for example, “mono-silanes” in the silane coupling agent had only three hydrolyzable -OR groups attached to the silicon (Si), and “bis-silane” had 6 hydrolyzable -OR groups and two Si atoms were at the end of molecules, and the coating effect of “bis-silane” coated particles was better than that of “mono-silanes” coated particles. 22 In addition, it was reported that the increase of the -OH functional groups on the CIP could enhance its surface activity, and the surface of CIP showed the Lewis acidity after being etched with HCl. 23–24 Moreover, the increase of specific surface area of particles could also improve the coated mass of polymers. 25–26 After the CIP was etched by the mixed solution of ferric chloride and citric acid, its specific surface area increased from 0.038 m 2 /g to 3.107 m 2 /g. 27 In addition, the CIP was etched by the mixed solution of ferric chloride, ethylene glycerol and diluted nitric acid, particles with hollow structure were obtained, and their specific surface area increased from 2.4 m 2 /g to 11.2 m 2 /g. 28 Furthermore, after the CIP was etched with HCl, their pore size increased from 21 to 80 nm and their specific surface area increased from 1.24 to 16.92 m 2 /g. 29 It follows that the chain lengths of silane coupling agents, the number of grafted functional groups, the number of -OH functional groups and the specific surface area of particles, all will affect the coating effect of CIP, and thus the dispersion stability of MRF could be improved. In order to expand the application and development of MRF, there is an urgent need for improvement of their long-term dispersion stability. In this study, the CIPs were etched with different concentrations of HCl and then coated with BTES, and the particles were dispersed into polyalphaolefin synthetic oil (PAO) to prepare the MRF. The microscopic morphology, coating effect and magnetic properties of etched and coated CIPs, the rheological properties and dispersion stability of MRFs were characterized. The MRF with high yield stress and high dispersion stability were obtained, which will promote the application effect for a long time and has a great significance for basic theoretical research. Experiment Materials and chemicals The parameters of materials used in the experiment are shown in the Table 1 . Table 1 The parameters of materials used in the experiment Materials Chemical formula Purity Manufacturer Hydrochloric acid HCl AR Chengdu Colon Chemical Co., Ltd Anhydrous ethanol C 2 H 5 OH AR Carbonyl iron particles Fe(CO) 5 ≥ 99.9% Shanghai Xiangtian Nanomaterials Co., Ltd 1,2-bis (triethoxy-silyl) ethane C 14 H 34 O 6 Si 2 ≥ 95% Shanghai Maclin Technology Co., Ltd Polyalphaolefin synthetic oil —— ≥ 99% Shanghai Nac Lubrication Technology Co. Ltd Ultra-pure water H 2 O —— Self-preparation Preparation method The preparation of particles : Fig. 1 illustrates the treating process of particles. Firstly, the CIP of 40 g was etched by HCl solution with different concentrations at 250 rpm for 10 minutes, the etched particles were obtained, labelled as sample A ~ F. Secondly, the etched particles were coated with 5g BTES in the mixed solution of 200 ml ethanol and 15ml water, at 250 rpm for 2 hours. Finally, the coated particles were obtained, labelled as sample R-1 to R-5. Preparation of MRF : The MRFs were prepared by mixing the coated particles and PAO with a mass ratio of 3:2, at 600 rpm for 2 hours. The parameters of the MRFs are shown in Table 2 . Table 2 The parameters of the prepared MRFs MRF sample Particles (12g) Carrier medium (8g) M−1 CIP PAO−100 M−2 R−1 M−3 R−2 M−4 R−3 M−5 R−4 M−6 R−5 Characterization method The microscopic morphology of the CIP was characterized using a scanning electron microscopy (SEM, Phenom Pharos G2), and the magnifications are 20,000x. The specific surface area and porous structure characteristics of the CIP were calculated by an automatic surface and porosity analyzer (BTE, Micromeritics ASAP 2460), and the removal temperature was 120 o C by nitrogen adsorption. The coated effect of particles were studied by a fourier-transform infrared spectroscopy (FTIR, Nicolet iS 10), with wavenumbers ranging from 500 to 4000 cm − 1 . The coated mass of the particle was calculated by a thermal gravimetric analyzer (TGA, TA), under the condition of a nitrogen atmosphere, the temperature range was from 30 o C to 600 o C, and the heating rate was 20 o C/min. The magnetic properties of the particles were measured by a vibrating sample magnetometer (VSM, Lake Shore 7404), and the applied field range of -2.0×10 4 Oe to + 2.0×10 4 Oe at 25 o C. The magnetorheological properties of the MRF were measured using a rotary rheometer (MCR 302e Anton Paar, Austria), the measuring system is PP25-SN3320, the test unit is P-PTD200, and the magnetic field is controlled by the magnetic control system (MRD 170/1T). The sample platform is parallel plate with a shear disc gap of 1 mm, the magnetic field strengths of 0 and 174 kA/m, and a shear rate ranging from 0.1 to 1000 s − 1 . The dispersion stability of the MRF was measured by a turbiscan-tower (Formulation, France), and the MRF was placed into a cylindrical glass tube, and the samples were periodically scanned from bottom to top by the beam of near-infrared light ( λ = 880 nm), and the migration rates of the particles were derived. Results and discussion The morphology of the particles Table 3 The characteristic parameters of particles etched with HCl of different concentrations Sample S BET (m 2 /g) S BJH (m 2 /g) V BJH (cm 3 /g) A 0.4640 0.4400 0.000953 B 0.5045 0.4326 0.001902 C 2.6053 1.6847 0.003522 D 37.7697 27.0089 0.026672 E 43.5450 34.6350 0.033943 F 0.9172 1.1214 0.004098 Figure 2 shows the SEM images of CIPs etched by HCl of different concentrations. Figure 2 (a) shows that the purchased CIPs are regular spherical shape and their surface is smooth. Figure 2 (b) shows that spot-like solids appear on the CIPs and their surface is rough. Figure 2 (c) shows that more spot-like solids appear on the CIPs and it is worth noting that nanopores also appear, this spot-like solids result from that the α-Fe nanoparticles the component of CIPs, are exposed after the HCl-induced removal of the oxide covering. 30 Fig. 2 (d) shows that more nanopores appear on the CIPs after being etched with 0.50 mol/L HCl. Figure 2 (e) shows that the spot-like solids disappear on the CIPs after being etched with 1.00 mol/L HCl, meanwhile, the surface is still rough. Figure 2 (f) shows that the nanopores grow into depression on the CIPs after being etched with 3.00 mol/L HCl. With the increase of HCl concentration, the etching degree of CIPs is aggravated, the number of nanopores on the particles increases gradually, and eventually disappear when the concentration of HCl is 3.00 mol/L, due to that the surface of CIPs was exposed after being corroded by highly active H + , and the corrosion continued inwards along the particles boundary. 27,31 Table 3 shows the characteristic parameters of particles etched with different concentrations of HCl. In the table, the S BET is the specific surface area of CIP, the S BJH is the specific surface area of nanopores, and the V BJH is the specific volume of nanopores. The S BET of the purchased CIP is 0.4640 m 2 /g, after being etched with 0.05 mol/L HCl, the S BET increases to 0.5045 m 2 /g, and the change of S BJH and V BJH is not obvious, after being etched with 0.20 mol/L HCl, the S BET increases to 2.60535 m 2 /g, and the S BJH and V BJH increases to 1.6847 m 2 /g and 0.003522 cm 3 /g, showing that there are fewer nanopores appear on the CIP, and cause that the increases of the specific surface area. After being etched with 0.50 mol/L HCl, the S BET of CIP increases to 37.7697 m 2 /g, and the S BJH and V BJH increases to 27.0089 m 2 /g and 0.026672 cm 3 /g, showing that the huge number of nanopores appear on the CIP. After being etched with HCl of 1.00 mol/L, the S BET of CIP increases to 43.5450 m 2 /g, and the S BJH and V BJH increases to 34.6350 m 2 /g and 0.033943 cm 3 /g. However, when the concentration of HCl reached 3 mol/L, the S BET , S BJH and V BJH decrease significantly, showing that the porous structures of particles disappear. In has been reported that during the etching process, the iron atoms are easy to react with H + , leading to the breakdown of particles, the initiation and growth of nanopores and the passivation of particles, and which can be observed in the Figure 2, 28,32 and the reaction process is shown as the following equations (1)-(3). Etching process: 2Fe + O 2 + 4H + → 2Fe 2+ + 2H 2 O (1) 2Fe 2+ + 4OH - + 2H + → 2Fe(OH) 2 + H 2 (2) Further oxidized: 4Fe(OH) 2 + O 2 + H 2 O → 2Fe 2 O 3 ·xH 2 O (3) During the etching process, a large number of Fe-OH groups generated on the surface of the particles, caused by that the particle surface of CIPs shows Lewis acidity after being etched with HCl, resulting in the chemisorption of -OH from the H 2 O on etched particle surface, which will promote the coating effect of silane coupling agent on the CIPs and prevent the further oxidization of coated particles. 23-24,32 Figure 3 shows the SEM images of coated CIPs etched by HCl of different concentrations. With the increase of the concentration of HCl, the coated materials on the particles gradually increase, indicating that the etching of CIP could enhance the coated mass on the particles. 32 The coating effect of the BTES on particles The coating effect of the BTES on the particles was investigated using the FTIR and TGA curves, as shown in Fig. 4 . In Fig. 4 (a), the peaks located at 630.69cm − 1 , 1357.81 cm − 1 and 1384.81 cm − 1 indicate the existence of Fe-O, C-O-C and C = O bonds, respectively, and the peak at 3446.60 cm − 1 indicates the existence of -OH bond, which is attributing to the attached water on the particles. 33,34 The peaks located at 441.67 cm − 1 , 894.92 cm − 1 and 995.21 cm − 1 in the curves of coated particles confirm the existence of the Si-O, Si-C and Si-O-Si bonds from BTES, respectively. The existence of Si-O-Si bonds indicates that a polycondensation reaction occurs between the hydrolytic functional groups (Si-OH) of BTES molecules. 32–34 As shown in Fig. 4 (b), the mass increase only appears in curve (A) at near 300 o C, attributing to the chemical reaction between N 2 from the testing environment and the uncoated CIP particles. 35 The mass of coated particles decreased with the rise in temperature, owing to the decomposition of the coated BTES, and the decrease begins at about 100 ℃, owing to the water adsorbed. 36–37 The coated mass of particles increases as the increase of HCl concentration, and the coated mass loss were 0.68 wt.% (in curve R−1), 0.97 wt.% (in curve R−2), 2.45 wt.% (in curve R−3), 3.06 wt.% (in curve R−4) and 4.11 wt.% (in curve R−5), respectively. When the concentration of HCl was below 0.20 mol/L, the coated mass loss was less than 1 wt.%, and when the concentration of HCl was above 0.50 mol/L, the coated mass greatly increased to 2.45 wt.%, showing that it is difficult to coat the silane coupling agent on the CIPs when the concentration of HCl was not enough high. 20–21 Combine with the SEM images in Fig. 3 , the increase of the coated mass is due to that the sharply increase of the specific surface area and -OH functional groups of particles after being etched with high concentration of HCl. 28 Figure 5 shows the magnetization curves of particles. From the Fig. 5 (a), the saturation magnetization ( M s ) of particles decrease from 212.7 emu/g to 164.8 emu/g with the increase of HCl concentration, attributing to the oxidation reaction, as shown in Eq. (3). 32,38 When the concentration of HCl used to etch the CIPs was above 0.50 mol/L, the M s sharply decreased to 179.67 emu/g, according to the report, due to the formation of the porous structure during the etching process and the appearance of nanopores on the particles. 38 In Fig. 5 (b), the M s of coated particles is lower than that of the uncoated particles, and which decreases from 196.7 emu/g to 113.3 emu/g with the increase of coated mass, due to that the existence of coated non-magnetic molecule and which makes the distance between magnetic cores increase and makes the magnetic interaction force between particles reduce. 16 The rheological properties of MRFs Figure 6 shows the rheological properties of MRFs. In Fig. 6 (a), without a magnetic field, the viscosity of MRFs drop with the increases of shear rate. When the coated mass of the particles is above 2.45 wt.% the viscosity increases by an order of magnitude at the beginning of the shear, and a faster downward trend of viscosity appears at the same of shear rate, compared with samples M-1, M-2 and M-3. This is attribute to that the entanglement effect between the coated particles and the carrier medium molecules is enhanced, and the more stronger three-dimensional network structures form in the MRFs with the increases of coated mass of particles. 39 With the increases of the shear rate, the disentanglement and straightening between entangled molecules occurs, resulting in the destruction of the three-dimensional network structure and a rapidly decreases of viscosity shows. 40 In addition, as shown in Fig. 6 , the shear stress of M-4, M-5 and M-6 are higher and more stable at beginning of the shear than that of MRFs with coated mass loss less than 2.45 wt.%. Moreover, the formation of the three-dimensional network structure has been proved to effectively delay the gravitational sedimentation of particles in the carrier medium. 41,42 In Fig. 6 (c) and (d), under a magnetic filed, with the increase of coated mass on the particles, the viscosity and shear stress of MRFs is lower than that of MRF prepared by uncoated CIP particles, due to that formation of the porous structures on the CIPs after etching with HCl and the coated non-magnetospheric makes the saturation magnetization of the particles reduce. 43 The dispersion stability of the MRF Table 3 The migration rate of particles after the sedimentation of seven days Samples Peak thickness [mm] Sedimentation rate [mm h -1 ] M-1 24.15 0.13 M-2 17.28 0.09 M-3 6.64 0.04 M-4 2.50 0.01 M-5 2.28 0.01 M-6 1.83 0.01 The dispersion stability of MRFs was tested by a Turbiscan-Tower. The samples of MRFs were respectively placed in the sample units with a height of 40 mm, and the bottom of the sample was marked on the left side of the graph in the Fig. 7 , and the top of the sample was marked on the right side. The scanning was repeated within 7 days, which was denoted by the color of the lines, and the test result was expressed as backscattered intensity (ΔBS). The variation of ΔBS indicates the sedimentation of particles, the ΔBS decreased from 40 mm and gradually extended to the left end of the x-axis with sedimentation of particles. 44 Figure 7 shows that the typical turbiscan spectra of tested MRFs. It can be seen that the fluctuation range of ΔBS on the X-axis gradually decreases with the increase of sample sequence, indicating that the sedimentation of MRFs gradually decrease with the increase of coated mass on particles. Figure 8 shows the particle sedimentation value obtained according to the variation of ΔBS in Fig. 7 . The peak thickness is expressed as the specific sedimentation displacement of the particles in the sample unit over time. The peak thickness of M-1 is 24.15 mm, and ΔBS change from a negative peak to a positive peak at 15.85 mm in Fig. 7 , indicating the sedimentation position of the sample. The peak thickness of M-2 is 17.28 mm, and ΔBS change from a negative peak to a positive peak at 12.72 mm in Fig. 7 , indicating that the sedimentation position of the sample and the peak thickness of M-2 is smaller than that of M-1, and the coating of BTES has a positive effect on the dispersion stability of MRF. With the increases of coated mass on particles in the MRF, the peak thickness of particles decreases from 17.28 mm to 1.83 mm. Table 3 shows the peak thickness and sedimentation rate of particles after the sedimentation of 7 days, and the sedimentation rate of the MRF prepared by uncoated CIPs is 0.13 mm/h, and the sedimentation rates of the MRFs gradually decrease to 0.09 mm/h, 0.04 mm/h and 0.01 mm/h as the coated mass increases, this can be concluded to that the formation of a stronger three-dimensional network structure that provide the higher viscosity at the beginning of the shear, and the viscous resistance of the particles during sedimentation is enhanced. 40–42 In addition, when the coated mass loss of is higher than 2.45 wt.%, the sedimentation rate is close to 0.01 mm/h, indicating that the further increase of coated mass has a little effect on dispersion stability. Meanwhile, the excessive etching of CIPs makes the saturation magnetization of particles reduce and makes the non-magnetic coated mass on the particles increase, which will further reduces the saturation magnetization of particles, and thus which will seriously reduce the shear stress of MRFs under a magnetic field. Therefore, when the CIP is etched by HCl with the concentration of 0.5 mol/L, the coated mass loss is 2.45 wt.%, the sedimentation rate of MRF is 0.01 mm/h and which has better dispersion stability than the MRF prepared by uncoated CIPs, moreover, the decrease of field-induced shear stress caused by the decrease of saturation magnetization of particle is small. Conclusion The CIPs were etched by HCl with varying concentrations and then were coated with BTES and dispersed into PAO-100 for the preparation of the MRF. The microstructures, coating effect and magnetism of particles, as well as the rheological properties and dispersion stability of the MRFs were systematically characterized. As the concentration of HCl increased from 0.05 mol/L to 3.00 mol/L, the number of nanopores on the particles increased, and eventually disappeared, simultaneously, the specific surface area of the particles increased to 43.5450 m 2 /g and then decreased to 0.9172 m 2 /g. When the concentration of HCl was 0.50 mol/L, the number of nanopores and the specific surface area of particles sharply increased, due to that the particles had been etched by highly active H + from HCl. As the concentration of HCl increased, the coated mass on particles increased and the saturation magnetization of particle decreased, when the HCl concentration was 0.50 mol/L, the coated mass sharply increased to 2.45 wt.% and the saturation magnetization of uncoated particles sharply decreased, due to the formation of porous structures and the high specific surface area of the particles, and then the saturation magnetization of particles further decreased from 196.7 emu/g to 113.3 emu/g with the increase of coated mass on the particles. As the coated mass on particles increased, the viscosity and shear stress of MRFs increased without the magnetic filed, and when the coated mass loss was above 2.45 wt.%, the viscosity and shear stress, increased by an order of magnitude at the beginning of the shear, compared with MRF prepared by uncoated particles, due to the enhancement of the entanglement effect between the coated particles and the carrier medium molecules, and the formation of stronger three-dimensional network structures; the viscosity and shear stress of MRFs decreased under the magnetic filed, due to the decrease of magnetic properties of the coated particles. As the coated mass increased, the sedimentation rate of particles decreased from 0.13 to 0.01 mm/h, attributed to the formation of stronger three-dimensional network structure, when the coated mass was higher than 2.45 wt.%, the sedimentation rate of particles in MRFs were close to 0.01 mm/h. This MRFs with suitable shear stress and exceptional dispersion stability, striking a balance between coating effects, magnetic properties, and overall performance under a magnetic field. Declarations Author Contribution Conceptualization: Fang Chen and Jie Zhang. Investigation: Qinkui Guo and Yuchen Liu. Supervision: Zhenggui Li and Xiaobing Liu. Project administration: Shengnan Yan and Zhaoqiang Yan. All authors reviewed the manuscript. ACKNOWLEDGMENT Authors F.C. and J.Z. would like to thank the National Natural Science Foundation of China (No. 52079118 and 52379092) and the Study on the effect of ion doping on the properties of ferrite nanoparticles and flurane oil-based magnetic liquids, third prize of the Sichuan Province Postdoctoral Research Project in 2021 for the financial support. References M. Cvek, M. Mrlik, M. Ilcikova, T. Plachy, M. Sedlacik, J. Mosnacek, V. Pavlinek, A facile controllable coating of carbonyl iron particles with poly (glycidyl methacrylate): a tool for adjusting MR response and stability properties, J Mater Chem C. 3(18) (2015) 4646–4656. A. V. Feijoo, M. T. Lopez-Lopez, C. Galindo-Gonzalez, S. Stange, T. T. Nguyen, F. Mammeri, S. Merash, A. Ponton, Rheological investigation of magnetic sensitive biopolymer composites: effect of the ligand grafting of magnetic nanoparticles, Rheol Acta. 59(3) (2020) 165–176. J. A. Marins, T. Plachý, P. Kuzhir, Iron–sepiolite magnetorheological fluids with improved performances, J RHEOL. 63(1) (2019) 125–139. W. I.Kordonski, S. D. Jacobs, Magnetorheological finishing, Int J Mod Phys B. 10(23n24) (1996) 2837–2848. D. N. Miriyala, P. S. Goyal, Effect of MagneticField on the Damping Behavior of a Ferrofluid based Damper, arXiv. 2201 (2022) 09027. J. Rabinow, The magnetic fluid clutch, ELECTR ENG. 67(12) (1951) 1167–1167. C. Scherer, A. M. Figueiredo Neto, Ferrofluids: properties and applications, Braz J Phys. 35 (2005) 718–727. M. S. Kim, Y. D. Liu, B. J. Park, C. Y. You, H. J. Choi, Carbonyl iron particles dispersed in a polymer solution and their rheological characteristics under applied magnetic field, J Ind Eng Chem. 18(2) (2012) 664–667. Y. Sun, Y. Wang, H. Deng, M. Sang, X. Gong, Effect of MXene nanosheets attached to carbonyl iron microspheres on the performance and stability of magnetorheological fluid, J Ind Eng Chem. 114 (2022) 508–517. R. C. Bell, J. O. Karli, A. N. Vavreck, D. T. Zimmerman, G. T. Ngatu, N. M. Wereley, Magnetorheology of submicron diameter iron microwires dispersed in silicone oil, Smart Mater Struct. 17(1) (2008) 015028. W. L. Zhang, S. D. Kim, H. J. Choi, Effect of graphene oxide on carbonyl-iron-based magnetorheological fluid, IEEE T MAGN. 50(1) (2013) 1–4. M. N. Aruna, M. R. Rahman, S. Joladarashi, H. Kumar, P. D. Bhat, Influence of different fumed silica as thixotropic additive on carbonyl particles magnetorheological fluids for sedimentation effects, J Magn Magn Mater. 529 (2021) 167910. L. Xie, Y. T. Choi, C. R. Liao, N. M. Wereley, Long term stability of magnetorheological fluids using high viscosity linear polysiloxane carrier fluids, Smart Mater Struct. 25(7) (2016) 075006. S. Kumar, R. Sehgal, M. F. Wani, M. D. Sharma, Stabilization and tribological properties of magnetorheological (MR) fluids: A review, J Magn Magn Mater. 538 (2021) 168295. I. B. Jang, H. B. Kim,J. Y. Lee, J. L. You, H. J. Choi, M. S. Jhon, Role of organic coating on carbonyl iron suspended particles in magnetorheological fluids, J Appl Phys. 97(10) (2005). W. H. Chuah, W. L. Zhang, H. J. Choi, Y. Seo, Magnetorheology of core–shell structured carbonyl iron/polystyrene foam microparticles suspension with enhanced stability, Macromolecules. 48(19) (2015) 7311–7319. W. Jiang, H. Zhu, C. Guo, J. Li, Q. Xue, J. Feng, X. Gong, Poly (methyl methacrylate)-coated carbonyl iron particles and their magnetorheological characteristics, Polymer International. 59(7) (2010) 879–883. K. V. Swaroop, M. N. Aruna, H. Kumar, M. R. Rahman, Rheological characterization of tragacanth gum coated carbonyl particles based magnetorheological fluid, ADVANCES IN MECHANICAL DESIGN, MATERIALS AND MANUFACTURE: Proceeding of the Second International Conference on Design, Materials and Manufacture. (2020) (Vol. 2247, No. 1). J. W. Lee, K. P. Hong, S. H. Kwon, H. J. Choi, M. W. Cho, Suspension rheology and magnetorheological finishing characteristics of biopolymer-coated carbonyliron particles, Indus. Eng. Chem. Res. 56(9) (2017) 2416–2424. H. Cheng, M. Wang, C. Liu, N. M. Wereley, Improving sedimentation stability of magnetorheological fluids using an organic molecular particle coating, Smart Mater. Struct. 27(7) (2018) 075030. S. G. Belyavskii, P. G. Mingalyov, F. Giulieri, R. Combarrieau, G. V. Lisichkin, Chemical modification of the surface of a carbonyl iron powder, Prot Met+. 42 (2006) 244–252. W. J. Van Ooij, D. Q. Zhu, G. Prasad, S. Jayaseelan, Y. Fu, N. Teredesai, Silane based chromate replacements for corrosion control, paint adhesion, and rubber bonding, Surf Eng. 16(5) (2000) 386–396. Y. Joseph, W. Ranke, W. Weiss, Water on FeO(111) and Fe3O4(111): Adsorption Behavior on Different Surface Terminations, J. Phys. Chem. B. 104 (2000) 3224–3236. M. Breitbach, D. Bathen, H. Schmidt-Traub, Effect of Ultrasound on Adsorption and Desorption Processes, IND ENG CHEM RES. 42 (2003) 5635–5646. M. P. Merkel, V. L. Dimonie, M. S. El-Aasser, J. W. Vanderhoff, Process parameters and their effect on grafting reactions in core/shell latexes, J Polym Sci Pol Chem. 25(7) (1987) 1755–1767. T. Ai, R. Wang, W. Zhou, Effect of grafting alkoxysilane on the surface properties of Kevlar fiber, Polym Composite. 28(3) (2007) 412–416. G. X. Tong, W. H. Wu, Q. Hu, J. H. Yuan, R. Qiao, H. S. Qian, Enhanced electromagnetic characteristics of porous iron particles made by a facile corrosion technique, Mater Chem Phys. 132(2–3) (2012) 563–569. C. Yin, Y. Cao, J. Fan, L. Bai, F. Ding, F. Yuan, Synthesis of hollow carbonyl iron microspheres via pitting corrosion method and their microwave absorption properties, Appl Surf Sci. 270 (2013) 432–438. Q. Yu, P. Wang, S. Hu, J. Hui, J. Zhuang, X. Wang, Hydrothermal synthesis of hollow silica spheres under acidic conditions, Langmuir. 27(11) (2011) 7185–7191. R. König, S. Müller, R. E. Dinnebier, B. Hinrichsen, P. Müller, A. Ribbens, C. Pistidda, The crystal structures of carbonyl iron powder–revised using in situ synchrotron XRPD, Z Krist-Cryst Mater. 232(12) (2017) 835–842. M. Jafarian, S. S. S. Afghahi, Y. Atassi, M. Salehi, Enhanced microwave absorption characteristics of nanocomposite based on hollow carbonyl iron microspheres and polyaniline decorated with MWCNTs, J Magn Magn Mater. 462 (2018) 153–159. S. A. B. A. Aziz, S. A. Mazlan, N. A. Nordin, N. A. N. Abd Rahman, U. Ubaidillah, S. B. Choi, N. Mohamad, Material characterization of magnetorheological elastomers with corroded carbonyl iron particles: Morphological images and field-dependent viscoelastic properties, Int J Mol Sci. 20(13) (2019) 3311. Y. Chen, H. R. Chen, J. L. Shi, Construction of homogenous/heterogeneous hollow mesoporous silica nanostructures by silica-etching chemistry: principles, synthesis, and applications, Accounts Chem Res. 47(1) (2014) 125–137. K. V. Swaroop, M. N. Aruna, H. Kumar, M. R. Rahman, Investigation of steady state rheological properties and sedimentation of coated and pure carbonyl iron particles based magneto-rheological fluids, Mater. Today. 39 (2021) 1450–1455. K. Yang, M. Gu, Enhanced thermal conductivity of epoxy nanocomposites filled with hybrid filler system of triethylenetetramine-functionalized multi-walled carbon nanotube/silane-modified nano-sized silicon carbide, Compos. Part A: Appl. Sci. Manuf. 41(2) (2010) 215–221. G. Liu, Y. Chen, M. Gong, X. Liu, Z. K. Cui, Q. Pei, J. G, C. Huang, Q. Zhuang, Enhanced dielectric performance of PDMS-based three-phase percolative nanocomposite films incorporating a high dielectric constant ceramic and conductive multi-walled carbon nanotubes, J. Mater. Chem. C. 6(40) (2018) 10829–10837. K. Jiao, C. Zhou, N. Becerra-Mora, J. Fiske, P. Kohli, Vapor-enhanced covalently bound ultra-thin films on oxidized surfaces for enhanced resolution imaging, J. Mater. Chem. C. 4(37) (2016) 8634–8647. N. L. Burhannuddin, N. A. Nordin, S. A. Mazlan, S. A. A. Aziz, N. Kuwano, S. K. M. Jamari, Physicochemical characterization and rheological properties of magnetic elastomers containing different shapes of corroded carbonyl iron particles, Sci. Rep. 11(1) (2021) 868. V. V. Gorodov, S. A. Kostrov, R. A. Kamyshinskii, E. Y. Kramarenko, A. M. Muzafarov, Modification of carbonyl iron particles by carboxyl-containing polydimethylsiloxanes, Russian Chem. Bull. 67 (2018) 1639–1647. P. Zhao, T. Du, N. Ma X. Dong, M. Qi, Effect of interfacial shear strength between magnetic particles and carrier liquid on rheological properties of magnetorheological fluids, J Mol Liq. 369 (2023) 120929. Z. Feng, L. Yi, R. Hongjuan, Study of sedimentation stability of magnetorheological fluid, Adv. Mat. 4(1) (2015) 1–5. A. Ronzova, M. Sedlacik, M. Cvek, Magnetorheological fluids based on core–shell carbonyl iron particles modified by various organosilanes: synthesis, stability and performance, Soft Matter. 17(5) (2021) 1299–1306. T. Plachy, M. Cvek, L. Munster, B. Hanulikova, P. Suly, A. Vesel, Q. Cheng, Enhanced magnetorheological effect of suspensions based on carbonyl iron particles coated with poly(amidoamine) dendrons, Rheol. Acta. 60(5) (2021) 263–276. M. Cvek, M. Mrlik, R. Moucka, M. Sedlacik, A systematical study of the overall influence of carbon allotrope additives on performance, stability and redispersibility of magnetorheological fluids, Colloid Surface A. 543 (2018) 83–92. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-4052080","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":283429644,"identity":"9b5b9def-8ac6-45f8-93e2-19279c5ded3c","order_by":0,"name":"Jie Zhang","email":"","orcid":"","institution":"Xihua University","correspondingAuthor":false,"prefix":"","firstName":"Jie","middleName":"","lastName":"Zhang","suffix":""},{"id":283429648,"identity":"613a333d-9bfe-49f9-a43a-abb9ec7ed8c0","order_by":1,"name":"Fang 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University","correspondingAuthor":false,"prefix":"","firstName":"Shengnan","middleName":"","lastName":"Yan","suffix":""},{"id":283429654,"identity":"ba8d47b5-b2d3-47ff-83ab-f7b7fcd7eea8","order_by":6,"name":"Zhaoqiang Yan","email":"","orcid":"","institution":"Zigong Zhaoqiang Sealing Products Industrial Co., Ltd","correspondingAuthor":false,"prefix":"","firstName":"Zhaoqiang","middleName":"","lastName":"Yan","suffix":""},{"id":283429655,"identity":"0af8f0af-1e29-4c04-b0d8-9873a007f121","order_by":7,"name":"Zhenggui Li","email":"","orcid":"","institution":"Xihua University","correspondingAuthor":false,"prefix":"","firstName":"Zhenggui","middleName":"","lastName":"Li","suffix":""}],"badges":[],"createdAt":"2024-03-09 05:50:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4052080/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4052080/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":53541352,"identity":"cb0c8290-7b77-487a-b176-289f18c8d111","added_by":"auto","created_at":"2024-03-27 08:49:15","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":225706,"visible":true,"origin":"","legend":"\u003cp\u003eThe treating process of particles\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-4052080/v1/91efb07b2fc44e99c44e7905.png"},{"id":53541356,"identity":"16df4134-2f97-4239-b0e0-053d95e7d591","added_by":"auto","created_at":"2024-03-27 08:49:15","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":738339,"visible":true,"origin":"","legend":"\u003cp\u003eThe SEM images of particles etched by HCl of different concentrations: (a) 0 mol/L, (b) 0.05 mol/L, (c) 0.20 mol/L, (d) 0.50 mol/L, (e) 1.00 mol/L, (f) 3.00 mol/L\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4052080/v1/3d536c9f8fd92cbbf3d7f469.png"},{"id":53541351,"identity":"f4e4cf8b-65ed-42e5-8840-5ba0fbc2b518","added_by":"auto","created_at":"2024-03-27 08:49:14","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":454656,"visible":true,"origin":"","legend":"\u003cp\u003eThe SEM images of coated CIPs etched by HCl of different concentrations: (a) 0.05 mol/L, (b) 0.20 mol/L, (c) 0.50 mol/L, (d) 1.00 mol/L, (e) 3.00 mol/L\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-4052080/v1/13614747e1b4b15ce0299b85.png"},{"id":53541357,"identity":"0049b0b3-59c4-4915-9a78-c05bda100d99","added_by":"auto","created_at":"2024-03-27 08:49:15","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":84258,"visible":true,"origin":"","legend":"\u003cp\u003eCoating effect of CIPs: (a) FTIR curves, (b) TGA curves\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-4052080/v1/d7ddbb3c3bfe6b8724833bb7.png"},{"id":53541353,"identity":"1bf347eb-5691-4257-a767-646357707816","added_by":"auto","created_at":"2024-03-27 08:49:15","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":47103,"visible":true,"origin":"","legend":"\u003cp\u003eThe magnetization curves of the particles: (a) Uncoated particles, (b) Coated particles\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-4052080/v1/7b902c819d6bfe193e39ea32.png"},{"id":53541359,"identity":"e6481bb7-0e5f-4816-b5e2-b75883631d9d","added_by":"auto","created_at":"2024-03-27 08:49:18","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":167440,"visible":true,"origin":"","legend":"\u003cp\u003eThe rheological properties of the MRFs : (a) The viscosity vs shear rate (0 kA/m), (b) The shear stress vs shear rate (0 kA/m), (c) The viscosity vs shear rate (175 kA/m), (d) The shear stress vs shear rate (175 kA/m)\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-4052080/v1/426def3c16a4438639b7f1f0.png"},{"id":53541354,"identity":"b0d8d0b0-567f-46c5-94c3-ee515cd49df5","added_by":"auto","created_at":"2024-03-27 08:49:15","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":146237,"visible":true,"origin":"","legend":"\u003cp\u003eTypical Turbiscan spectra of tested MRFs: (a) M-1, (b) M-2, (c) M-3, (d) M-4, (e) M-5, (f) M-6\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-4052080/v1/874033af6152927c6817b210.png"},{"id":53541355,"identity":"05a280e2-3877-44ba-9b1d-9bbb0188529e","added_by":"auto","created_at":"2024-03-27 08:49:15","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":45474,"visible":true,"origin":"","legend":"\u003cp\u003eThe peak thicknesses variation of particles over seven days\u003c/p\u003e","description":"","filename":"8.png","url":"https://assets-eu.researchsquare.com/files/rs-4052080/v1/9ae4d34460014624136f088a.png"},{"id":55265667,"identity":"c84ea555-f67d-4baf-ae43-4a5f9ad50456","added_by":"auto","created_at":"2024-04-25 02:13:08","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2570488,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4052080/v1/6e6cd1ea-e8c8-4fdf-9eef-89119ba37d36.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"\u003cp\u003eThe enhanced coating effect of carbonyl iron particles and improved dispersion stability of magnetorheological fluid\u003c/p\u003e","fulltext":[{"header":"Introduction","content":"\u003cp\u003eMagnetorheological fluid (MRF) is kind of intelligent material that its rheological properties transforms with changing the external magnetic field. The components of MRF mainly are micron sized magnetic particles, carrier medium and additives. without a magnetic field, the magnetic particles are randomly dispersed in the carrier medium, showing the characteristics of a free flowing Newtonian fluid; under a magnetic field, chain structures are arranged along the magnetic field direction, and the chain structures become thicker with the increase of the magnetic field strength, showing the characteristics of a solid-like pseudoplastic fluid.\u003csup\u003e1\u0026ndash;3\u003c/sup\u003e Due to the special rheological properties of MRF, it is widely used in buildings, cars, seals, medicals and other fields.\u003csup\u003e4\u0026ndash;7\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eMicron-sized CIPs are favored in MRF for their high saturation magnetization, excellent paramagnetic characteristics, optimal size and easy accessibility, thus they are typically utilized as magnetic particles in MRF. However, the MRF faces a significant challenge of severe sedimentation, attributing to the obvious density difference between CIP (7.8 g/cm\u0026sup3;) and the carrier medium (e.g., silicone oil at 0.963 g/cm\u0026sup3;), and this sedimentation adversely impacts the rheological properties of the MRF, results in the unbalanced distribution of yield stress in MRF.\u003csup\u003e8\u0026ndash;9\u003c/sup\u003e Thus, a number of strategies have been used to reduce the sedimentation, such as the use of rod-shaped magnetic particles,\u003csup\u003e10\u003c/sup\u003e the addition of graphene oxide,\u003csup\u003e11\u003c/sup\u003e the addition of fumed silica,\u003csup\u003e12\u003c/sup\u003e the use of high viscosity fluid as carrier medium,\u003csup\u003e13\u0026ndash;14\u003c/sup\u003e and the coat of particles with polymer.\u003csup\u003e15\u003c/sup\u003e Of which, it had been reported that the CIP was coated with polystyrene foam, and the sedimentation rate of the MRF decreased from 80\u0026ndash;30% compared with the MRF prepared by pure CIP.\u003csup\u003e16\u003c/sup\u003e The CIP was coated with poly(methyl methacrylate) (PMMA) by emulsion polymerization which reduced the density of particles and the sedimentation rate of the MRF decreased from 80\u0026ndash;70% compared with the MRF prepared by CIP.\u003csup\u003e17\u003c/sup\u003e The CIP was coated with tragacanth gum, and the sedimentation rate of the MRF decreased from 15\u0026ndash;10% compared with the MRF prepared by pure CIP.\u003csup\u003e18\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eThe coating of the CIP with polymers could improve the dispersion stability of MRF.\u003csup\u003e19\u0026ndash;20\u003c/sup\u003e To enhance the coating effect, Belyavskiiet al. reported that the particles were coated with silane coupling agents of different chain lengths, indicated that short chain molecules could increase their graft density on the particles.\u003csup\u003e21\u003c/sup\u003e The number of grafted functional groups of the coated molecules will also affect the coating effect, for example, \u0026ldquo;mono-silanes\u0026rdquo; in the silane coupling agent had only three hydrolyzable -OR groups attached to the silicon (Si), and \u0026ldquo;bis-silane\u0026rdquo; had 6 hydrolyzable -OR groups and two Si atoms were at the end of molecules, and the coating effect of \u0026ldquo;bis-silane\u0026rdquo; coated particles was better than that of \u0026ldquo;mono-silanes\u0026rdquo; coated particles.\u003csup\u003e22\u003c/sup\u003e In addition, it was reported that the increase of the -OH functional groups on the CIP could enhance its surface activity, and the surface of CIP showed the Lewis acidity after being etched with HCl.\u003csup\u003e23\u0026ndash;24\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eMoreover, the increase of specific surface area of particles could also improve the coated mass of polymers.\u003csup\u003e25\u0026ndash;26\u003c/sup\u003e After the CIP was etched by the mixed solution of ferric chloride and citric acid, its specific surface area increased from 0.038 m\u003csup\u003e2\u003c/sup\u003e/g to 3.107 m\u003csup\u003e2\u003c/sup\u003e/g.\u003csup\u003e27\u003c/sup\u003e In addition, the CIP was etched by the mixed solution of ferric chloride, ethylene glycerol and diluted nitric acid, particles with hollow structure were obtained, and their specific surface area increased from 2.4 m\u003csup\u003e2\u003c/sup\u003e/g to 11.2 m\u003csup\u003e2\u003c/sup\u003e/g.\u003csup\u003e28\u003c/sup\u003e Furthermore, after the CIP was etched with HCl, their pore size increased from 21 to 80 nm and their specific surface area increased from 1.24 to 16.92 m\u003csup\u003e2\u003c/sup\u003e/g.\u003csup\u003e29\u003c/sup\u003e It follows that the chain lengths of silane coupling agents, the number of grafted functional groups, the number of -OH functional groups and the specific surface area of particles, all will affect the coating effect of CIP, and thus the dispersion stability of MRF could be improved.\u003c/p\u003e \u003cp\u003eIn order to expand the application and development of MRF, there is an urgent need for improvement of their long-term dispersion stability. In this study, the CIPs were etched with different concentrations of HCl and then coated with BTES, and the particles were dispersed into polyalphaolefin synthetic oil (PAO) to prepare the MRF. The microscopic morphology, coating effect and magnetic properties of etched and coated CIPs, the rheological properties and dispersion stability of MRFs were characterized. The MRF with high yield stress and high dispersion stability were obtained, which will promote the application effect for a long time and has a great significance for basic theoretical research.\u003c/p\u003e"},{"header":"Experiment","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eMaterials and chemicals\u003c/h2\u003e \u003cp\u003eThe parameters of materials used in the experiment are shown in the Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe parameters of materials used in the experiment\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMaterials\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eChemical formula\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003ePurity\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eManufacturer\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eHydrochloric acid\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eHCl\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAR\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eChengdu Colon Chemical Co., Ltd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAnhydrous ethanol\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e2\u003c/sub\u003eH\u003csub\u003e5\u003c/sub\u003eOH\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAR\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCarbonyl iron particles\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eFe(CO)\u003csub\u003e5\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;99.9%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eShanghai Xiangtian Nanomaterials Co., Ltd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1,2-bis (triethoxy-silyl) ethane\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eC\u003csub\u003e14\u003c/sub\u003eH\u003csub\u003e34\u003c/sub\u003eO\u003csub\u003e6\u003c/sub\u003eSi\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;95%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eShanghai Maclin Technology Co., Ltd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePolyalphaolefin synthetic oil\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cb\u003e\u0026mdash;\u0026mdash;\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u0026ge;\u0026thinsp;99%\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eShanghai Nac Lubrication Technology Co. Ltd\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eUltra-pure water\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eH\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cb\u003e\u0026mdash;\u0026mdash;\u003c/b\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003eSelf-preparation\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003ePreparation method\u003c/h2\u003e \u003cp\u003e \u003cspan type=\"ItalicUnderline\" class=\"ItalicUnderline\" name=\"Emphasis\"\u003eThe preparation of particles\u003c/span\u003e: Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e illustrates the treating process of particles. Firstly, the CIP of 40 g was etched by HCl solution with different concentrations at 250 rpm for 10 minutes, the etched particles were obtained, labelled as sample A\u0026thinsp;~\u0026thinsp;F. Secondly, the etched particles were coated with 5g BTES in the mixed solution of 200 ml ethanol and 15ml water, at 250 rpm for 2 hours. Finally, the coated particles were obtained, labelled as sample R-1 to R-5.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cspan type=\"ItalicUnderline\" class=\"ItalicUnderline\" name=\"Emphasis\"\u003ePreparation of MRF\u003c/span\u003e: The MRFs were prepared by mixing the coated particles and PAO with a mass ratio of 3:2, at 600 rpm for 2 hours. The parameters of the MRFs are shown in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe parameters of the prepared MRFs\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMRF sample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eParticles (12g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCarrier medium (8g)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM\u0026minus;1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eCIP\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\" morerows=\"5\" rowspan=\"6\"\u003e \u003cp\u003ePAO\u0026minus;100\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM\u0026minus;2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eR\u0026minus;1\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM\u0026minus;3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eR\u0026minus;2\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM\u0026minus;4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eR\u0026minus;3\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM\u0026minus;5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eR\u0026minus;4\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM\u0026minus;6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eR\u0026minus;5\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eCharacterization method\u003c/h2\u003e \u003cp\u003eThe microscopic morphology of the CIP was characterized using a scanning electron microscopy (SEM, Phenom Pharos G2), and the magnifications are 20,000x. The specific surface area and porous structure characteristics of the CIP were calculated by an automatic surface and porosity analyzer (BTE, Micromeritics ASAP 2460), and the removal temperature was 120 \u003csup\u003eo\u003c/sup\u003eC by nitrogen adsorption. The coated effect of particles were studied by a fourier-transform infrared spectroscopy (FTIR, Nicolet iS 10), with wavenumbers ranging from 500 to 4000 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The coated mass of the particle was calculated by a thermal gravimetric analyzer (TGA, TA), under the condition of a nitrogen atmosphere, the temperature range was from 30 \u003csup\u003eo\u003c/sup\u003eC to 600 \u003csup\u003eo\u003c/sup\u003eC, and the heating rate was 20 \u003csup\u003eo\u003c/sup\u003eC/min. The magnetic properties of the particles were measured by a vibrating sample magnetometer (VSM, Lake Shore 7404), and the applied field range of -2.0\u0026times;10\u003csup\u003e4\u003c/sup\u003e Oe to +\u0026thinsp;2.0\u0026times;10\u003csup\u003e4\u003c/sup\u003e Oe at 25 \u003csup\u003eo\u003c/sup\u003eC. The magnetorheological properties of the MRF were measured using a rotary rheometer (MCR 302e Anton Paar, Austria), the measuring system is PP25-SN3320, the test unit is P-PTD200, and the magnetic field is controlled by the magnetic control system (MRD 170/1T). The sample platform is parallel plate with a shear disc gap of 1 mm, the magnetic field strengths of 0 and 174 kA/m, and a shear rate ranging from 0.1 to 1000 s\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. The dispersion stability of the MRF was measured by a turbiscan-tower (Formulation, France), and the MRF was placed into a cylindrical glass tube, and the samples were periodically scanned from bottom to top by the beam of near-infrared light (\u003cem\u003eλ\u003c/em\u003e\u0026thinsp;=\u0026thinsp;880 nm), and the migration rates of the particles were derived.\u003c/p\u003e \u003c/div\u003e"},{"header":"Results and discussion","content":"\u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eThe morphology of the particles\u003c/h2\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe characteristic parameters of particles etched with HCl of different concentrations\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"4\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e (m\u003csup\u003e2\u003c/sup\u003e/g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003eS\u003c/em\u003e\u003csub\u003eBJH\u003c/sub\u003e (m\u003csup\u003e2\u003c/sup\u003e/g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003eV\u003c/em\u003e\u003csub\u003eBJH\u003c/sub\u003e (cm\u003csup\u003e3\u003c/sup\u003e/g)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.4640\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.4400\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.000953\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.5045\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.4326\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.001902\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.6053\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.6847\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.003522\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eD\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e37.7697\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e27.0089\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.026672\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eE\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e43.5450\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e34.6350\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.033943\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eF\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.9172\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.1214\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.004098\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the SEM images of CIPs etched by HCl of different concentrations. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(a) shows that the purchased CIPs are regular spherical shape and their surface is smooth. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(b) shows that spot-like solids appear on the CIPs and their surface is rough. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(c) shows that more spot-like solids appear on the CIPs and it is worth noting that nanopores also appear, this spot-like solids result from that the α-Fe nanoparticles the component of CIPs, are exposed after the HCl-induced removal of the oxide covering.\u003csup\u003e30\u003c/sup\u003e Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(d) shows that more nanopores appear on the CIPs after being etched with 0.50 mol/L HCl. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(e) shows that the spot-like solids disappear on the CIPs after being etched with 1.00 mol/L HCl, meanwhile, the surface is still rough. Figure\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e(f) shows that the nanopores grow into depression on the CIPs after being etched with 3.00 mol/L HCl. With the increase of HCl concentration, the etching degree of CIPs is aggravated, the number of nanopores on the particles increases gradually, and eventually disappear when the concentration of HCl is 3.00 mol/L, due to that the surface of CIPs was exposed after being corroded by highly active H\u003csup\u003e+\u003c/sup\u003e, and the corrosion continued inwards along the particles boundary.\u003csup\u003e27,31\u003c/sup\u003e\u003c/p\u003e \n\u003cp\u003eTable 3 shows the characteristic parameters of particles etched with different concentrations of HCl. In the table, the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e is the specific surface area of CIP, the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBJH\u003c/sub\u003e is the specific surface area of nanopores, and the \u003cem\u003eV\u003c/em\u003e\u003csub\u003eBJH\u003c/sub\u003e is the specific volume of nanopores. The \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e of the purchased CIP is 0.4640 m\u003csup\u003e2\u003c/sup\u003e/g, after being etched with 0.05 mol/L HCl, the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e increases to 0.5045 m\u003csup\u003e2\u003c/sup\u003e/g, and the change of \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBJH\u003c/sub\u003e and \u003cem\u003eV\u003c/em\u003e\u003csub\u003eBJH\u003c/sub\u003e is not obvious, after being etched with 0.20 mol/L HCl, the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e increases to 2.60535 m\u003csup\u003e2\u003c/sup\u003e/g, and the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBJH\u0026nbsp;\u003c/sub\u003eand \u003cem\u003eV\u003c/em\u003e\u003csub\u003eBJH\u0026nbsp;\u003c/sub\u003eincreases to 1.6847 m\u003csup\u003e2\u003c/sup\u003e/g and 0.003522 cm\u003csup\u003e3\u003c/sup\u003e/g, showing that there are fewer nanopores appear on the CIP, and cause that the increases of the specific surface area. After being etched with 0.50 mol/L HCl, the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e of CIP increases to 37.7697 m\u003csup\u003e2\u003c/sup\u003e/g, and the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBJH\u0026nbsp;\u003c/sub\u003eand \u003cem\u003eV\u003c/em\u003e\u003csub\u003eBJH\u0026nbsp;\u003c/sub\u003eincreases to 27.0089 m\u003csup\u003e2\u003c/sup\u003e/g and 0.026672 cm\u003csup\u003e3\u003c/sup\u003e/g, showing that the huge number of nanopores appear on the CIP. After being etched with HCl of 1.00 mol/L, the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e of CIP increases to 43.5450 m\u003csup\u003e2\u003c/sup\u003e/g, and the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBJH\u0026nbsp;\u003c/sub\u003eand \u003cem\u003eV\u003c/em\u003e\u003csub\u003eBJH\u0026nbsp;\u003c/sub\u003eincreases to 34.6350 m\u003csup\u003e2\u003c/sup\u003e/g and 0.033943 cm\u003csup\u003e3\u003c/sup\u003e/g. However, when the concentration of HCl reached 3 mol/L, the \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBET\u003c/sub\u003e, \u003cem\u003eS\u003c/em\u003e\u003csub\u003eBJH\u003c/sub\u003e and \u003cem\u003eV\u003c/em\u003e\u003csub\u003eBJH\u003c/sub\u003e decrease significantly, showing that the porous structures of particles disappear. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003eIn has been reported that during the etching process, the iron atoms are easy to react with H\u003csup\u003e+\u003c/sup\u003e, leading to the breakdown of particles, the initiation and growth of nanopores and the passivation of particles, and which can be observed in the Figure 2,\u003csup\u003e28,32\u003c/sup\u003e and the reaction process is shown as the following equations (1)-(3).\u003c/p\u003e\n\u003ctable border=\"0\" cellspacing=\"0\" cellpadding=\"0\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd width=\"86.46034816247582%\"\u003e\n \u003cp\u003eEtching process: 2Fe + O\u003csub\u003e2\u003c/sub\u003e + 4H\u003csup\u003e+\u003c/sup\u003e \u0026rarr; 2Fe\u003csup\u003e2+\u003c/sup\u003e + 2H\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.539651837524177%\" valign=\"top\"\u003e\n \u003cp\u003e(1)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"86.46034816247582%\"\u003e\n \u003cp\u003e2Fe\u003csup\u003e2+\u003c/sup\u003e + 4OH\u003csup\u003e-\u003c/sup\u003e + 2H\u003csup\u003e+\u003c/sup\u003e \u0026rarr; 2Fe(OH)\u003csub\u003e2\u003c/sub\u003e + H\u003csub\u003e2\u003c/sub\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.539651837524177%\" valign=\"top\"\u003e\n \u003cp\u003e(2)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd width=\"86.46034816247582%\"\u003e\n \u003cp\u003eFurther oxidized: 4Fe(OH)\u003csub\u003e2\u0026nbsp;\u003c/sub\u003e+ O\u003csub\u003e2\u003c/sub\u003e + H\u003csub\u003e2\u003c/sub\u003eO \u0026rarr; 2Fe\u003csub\u003e2\u003c/sub\u003eO\u003csub\u003e3\u003c/sub\u003e\u0026middot;xH\u003csub\u003e2\u003c/sub\u003eO\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd width=\"13.539651837524177%\" valign=\"top\"\u003e\n \u003cp\u003e(3)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n\u003c/table\u003e\n\u003cp\u003eDuring the etching process, a large number of Fe-OH groups generated on the surface of the particles, caused by that the particle surface of CIPs shows Lewis acidity after being etched with HCl, resulting in the chemisorption of -OH from the H\u003csub\u003e2\u003c/sub\u003eO on etched particle surface, which will promote the coating effect of silane coupling agent on the CIPs and prevent the further oxidization of coated particles.\u003csup\u003e23-24,32\u003c/sup\u003e\u003c/p\u003e\n\u003cp\u003eFigure \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the SEM images of coated CIPs etched by HCl of different concentrations. With the increase of the concentration of HCl, the coated materials on the particles gradually increase, indicating that the etching of CIP could enhance the coated mass on the particles.\u003csup\u003e32\u003c/sup\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003eThe coating effect of the BTES on particles\u003c/h2\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe coating effect of the BTES on the particles was investigated using the FTIR and TGA curves, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e. In Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e(a), the peaks located at 630.69cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 1357.81 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 1384.81 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e indicate the existence of Fe-O, C-O-C and C\u0026thinsp;=\u0026thinsp;O bonds, respectively, and the peak at 3446.60 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e indicates the existence of -OH bond, which is attributing to the attached water on the particles.\u003csup\u003e33,34\u003c/sup\u003e The peaks located at 441.67 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e, 894.92 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e and 995.21 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e in the curves of coated particles confirm the existence of the Si-O, Si-C and Si-O-Si bonds from BTES, respectively. The existence of Si-O-Si bonds indicates that a polycondensation reaction occurs between the hydrolytic functional groups (Si-OH) of BTES molecules.\u003csup\u003e32\u0026ndash;34\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eAs shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e(b), the mass increase only appears in curve (A) at near 300 \u003csup\u003eo\u003c/sup\u003eC, attributing to the chemical reaction between N\u003csub\u003e2\u003c/sub\u003e from the testing environment and the uncoated CIP particles.\u003csup\u003e35\u003c/sup\u003e The mass of coated particles decreased with the rise in temperature, owing to the decomposition of the coated BTES, and the decrease begins at about 100 ℃, owing to the water adsorbed.\u003csup\u003e36\u0026ndash;37\u003c/sup\u003e The coated mass of particles increases as the increase of HCl concentration, and the coated mass loss were 0.68 wt.% (in curve R\u0026minus;1), 0.97 wt.% (in curve R\u0026minus;2), 2.45 wt.% (in curve R\u0026minus;3), 3.06 wt.% (in curve R\u0026minus;4) and 4.11 wt.% (in curve R\u0026minus;5), respectively. When the concentration of HCl was below 0.20 mol/L, the coated mass loss was less than 1 wt.%, and when the concentration of HCl was above 0.50 mol/L, the coated mass greatly increased to 2.45 wt.%, showing that it is difficult to coat the silane coupling agent on the CIPs when the concentration of HCl was not enough high.\u003csup\u003e20\u0026ndash;21\u003c/sup\u003e Combine with the SEM images in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e, the increase of the coated mass is due to that the sharply increase of the specific surface area and -OH functional groups of particles after being etched with high concentration of HCl.\u003csup\u003e28\u003c/sup\u003e\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e shows the magnetization curves of particles. From the Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e(a), the saturation magnetization (\u003cem\u003eM\u003c/em\u003e\u003csub\u003e\u003cem\u003es\u003c/em\u003e\u003c/sub\u003e) of particles decrease from 212.7 emu/g to 164.8 emu/g with the increase of HCl concentration, attributing to the oxidation reaction, as shown in Eq.\u0026nbsp;(3).\u003csup\u003e32,38\u003c/sup\u003e When the concentration of HCl used to etch the CIPs was above 0.50 mol/L, the \u003cem\u003eM\u003c/em\u003e\u003csub\u003es\u003c/sub\u003e sharply decreased to 179.67 emu/g, according to the report, due to the formation of the porous structure during the etching process and the appearance of nanopores on the particles.\u003csup\u003e38\u003c/sup\u003e In Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e(b), the \u003cem\u003eM\u003c/em\u003e\u003csub\u003es\u003c/sub\u003e of coated particles is lower than that of the uncoated particles, and which decreases from 196.7 emu/g to 113.3 emu/g with the increase of coated mass, due to that the existence of coated non-magnetic molecule and which makes the distance between magnetic cores increase and makes the magnetic interaction force between particles reduce.\u003csup\u003e16\u003c/sup\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eThe rheological properties of MRFs\u003c/h2\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e shows the rheological properties of MRFs. In Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e(a), without a magnetic field, the viscosity of MRFs drop with the increases of shear rate. When the coated mass of the particles is above 2.45 wt.% the viscosity increases by an order of magnitude at the beginning of the shear, and a faster downward trend of viscosity appears at the same of shear rate, compared with samples M-1, M-2 and M-3. This is attribute to that the entanglement effect between the coated particles and the carrier medium molecules is enhanced, and the more stronger three-dimensional network structures form in the MRFs with the increases of coated mass of particles.\u003csup\u003e39\u003c/sup\u003e With the increases of the shear rate, the disentanglement and straightening between entangled molecules occurs, resulting in the destruction of the three-dimensional network structure and a rapidly decreases of viscosity shows.\u003csup\u003e40\u003c/sup\u003e In addition, as shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e, the shear stress of M-4, M-5 and M-6 are higher and more stable at beginning of the shear than that of MRFs with coated mass loss less than 2.45 wt.%. Moreover, the formation of the three-dimensional network structure has been proved to effectively delay the gravitational sedimentation of particles in the carrier medium.\u003csup\u003e41,42\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eIn Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e(c) and (d), under a magnetic filed, with the increase of coated mass on the particles, the viscosity and shear stress of MRFs is lower than that of MRF prepared by uncoated CIP particles, due to that formation of the porous structures on the CIPs after etching with HCl and the coated non-magnetospheric makes the saturation magnetization of the particles reduce.\u003csup\u003e43\u003c/sup\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eThe dispersion stability of the MRF\u003c/h2\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eThe migration rate of particles after the sedimentation of seven days\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"3\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSamples\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePeak thickness [mm]\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eSedimentation rate [mm h\u003csup\u003e-1\u003c/sup\u003e]\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM-1\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e24.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.13\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM-2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e17.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.09\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM-3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6.64\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.04\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM-4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM-5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eM-6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.83\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.01\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eThe dispersion stability of MRFs was tested by a Turbiscan-Tower. The samples of MRFs were respectively placed in the sample units with a height of 40 mm, and the bottom of the sample was marked on the left side of the graph in the Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e, and the top of the sample was marked on the right side. The scanning was repeated within 7 days, which was denoted by the color of the lines, and the test result was expressed as backscattered intensity (ΔBS). The variation of ΔBS indicates the sedimentation of particles, the ΔBS decreased from 40 mm and gradually extended to the left end of the x-axis with sedimentation of particles.\u003csup\u003e44\u003c/sup\u003e\u003c/p\u003e \u003cp\u003eFigure \u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e shows that the typical turbiscan spectra of tested MRFs. It can be seen that the fluctuation range of ΔBS on the X-axis gradually decreases with the increase of sample sequence, indicating that the sedimentation of MRFs gradually decrease with the increase of coated mass on particles. Figure\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e8\u003c/span\u003e shows the particle sedimentation value obtained according to the variation of ΔBS in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e. The peak thickness is expressed as the specific sedimentation displacement of the particles in the sample unit over time.\u003c/p\u003e \u003cp\u003eThe peak thickness of M-1 is 24.15 mm, and ΔBS change from a negative peak to a positive peak at 15.85 mm in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e, indicating the sedimentation position of the sample. The peak thickness of M-2 is 17.28 mm, and ΔBS change from a negative peak to a positive peak at 12.72 mm in Fig.\u0026nbsp;\u003cspan refid=\"Fig7\" class=\"InternalRef\"\u003e7\u003c/span\u003e, indicating that the sedimentation position of the sample and the peak thickness of M-2 is smaller than that of M-1, and the coating of BTES has a positive effect on the dispersion stability of MRF.\u003c/p\u003e \u003cp\u003eWith the increases of coated mass on particles in the MRF, the peak thickness of particles decreases from 17.28 mm to 1.83 mm. Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e3\u003c/span\u003e shows the peak thickness and sedimentation rate of particles after the sedimentation of 7 days, and the sedimentation rate of the MRF prepared by uncoated CIPs is 0.13 mm/h, and the sedimentation rates of the MRFs gradually decrease to 0.09 mm/h, 0.04 mm/h and 0.01 mm/h as the coated mass increases, this can be concluded to that the formation of a stronger three-dimensional network structure that provide the higher viscosity at the beginning of the shear, and the viscous resistance of the particles during sedimentation is enhanced.\u003csup\u003e40\u0026ndash;42\u003c/sup\u003e In addition, when the coated mass loss of is higher than 2.45 wt.%, the sedimentation rate is close to 0.01 mm/h, indicating that the further increase of coated mass has a little effect on dispersion stability. Meanwhile, the excessive etching of CIPs makes the saturation magnetization of particles reduce and makes the non-magnetic coated mass on the particles increase, which will further reduces the saturation magnetization of particles, and thus which will seriously reduce the shear stress of MRFs under a magnetic field.\u003c/p\u003e \u003cp\u003eTherefore, when the CIP is etched by HCl with the concentration of 0.5 mol/L, the coated mass loss is 2.45 wt.%, the sedimentation rate of MRF is 0.01 mm/h and which has better dispersion stability than the MRF prepared by uncoated CIPs, moreover, the decrease of field-induced shear stress caused by the decrease of saturation magnetization of particle is small.\u003c/p\u003e \u003c/div\u003e"},{"header":"Conclusion","content":"\u003cp\u003eThe CIPs were etched by HCl with varying concentrations and then were coated with BTES and dispersed into PAO-100 for the preparation of the MRF. The microstructures, coating effect and magnetism of particles, as well as the rheological properties and dispersion stability of the MRFs were systematically characterized.\u003c/p\u003e \u003cp\u003eAs the concentration of HCl increased from 0.05 mol/L to 3.00 mol/L, the number of nanopores on the particles increased, and eventually disappeared, simultaneously, the specific surface area of the particles increased to 43.5450 m\u003csup\u003e2\u003c/sup\u003e/g and then decreased to 0.9172 m\u003csup\u003e2\u003c/sup\u003e/g. When the concentration of HCl was 0.50 mol/L, the number of nanopores and the specific surface area of particles sharply increased, due to that the particles had been etched by highly active H\u003csup\u003e+\u003c/sup\u003e\u0026thinsp;from HCl.\u003c/p\u003e \u003cp\u003eAs the concentration of HCl increased, the coated mass on particles increased and the saturation magnetization of particle decreased, when the HCl concentration was 0.50 mol/L, the coated mass sharply increased to 2.45 wt.% and the saturation magnetization of uncoated particles sharply decreased, due to the formation of porous structures and the high specific surface area of the particles, and then the saturation magnetization of particles further decreased from 196.7 emu/g to 113.3 emu/g with the increase of coated mass on the particles.\u003c/p\u003e \u003cp\u003eAs the coated mass on particles increased, the viscosity and shear stress of MRFs increased without the magnetic filed, and when the coated mass loss was above 2.45 wt.%, the viscosity and shear stress, increased by an order of magnitude at the beginning of the shear, compared with MRF prepared by uncoated particles, due to the enhancement of the entanglement effect between the coated particles and the carrier medium molecules, and the formation of stronger three-dimensional network structures; the viscosity and shear stress of MRFs decreased under the magnetic filed, due to the decrease of magnetic properties of the coated particles.\u003c/p\u003e \u003cp\u003eAs the coated mass increased, the sedimentation rate of particles decreased from 0.13 to 0.01 mm/h, attributed to the formation of stronger three-dimensional network structure, when the coated mass was higher than 2.45 wt.%, the sedimentation rate of particles in MRFs were close to 0.01 mm/h. This MRFs with suitable shear stress and exceptional dispersion stability, striking a balance between coating effects, magnetic properties, and overall performance under a magnetic field.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eConceptualization: Fang Chen and Jie Zhang. Investigation: Qinkui Guo and Yuchen Liu. Supervision: Zhenggui Li and Xiaobing Liu. Project administration: Shengnan Yan and Zhaoqiang Yan. All authors reviewed the manuscript.\u003c/p\u003e\u003ch2\u003eACKNOWLEDGMENT\u003c/h2\u003e \u003cp\u003eAuthors F.C. and J.Z. would like to thank the National Natural Science Foundation of China (No. 52079118 and 52379092) and the Study on the effect of ion doping on the properties of ferrite nanoparticles and flurane oil-based magnetic liquids, third prize of the Sichuan Province Postdoctoral Research Project in 2021 for the financial support.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eM. Cvek, M. Mrlik, M. Ilcikova, T. Plachy, M. Sedlacik, J. Mosnacek, V. Pavlinek, A facile controllable coating of carbonyl iron particles with poly (glycidyl methacrylate): a tool for adjusting MR response and stability properties, J Mater Chem C. 3(18) (2015) 4646\u0026ndash;4656.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eA. V. Feijoo, M. T. Lopez-Lopez, C. Galindo-Gonzalez, S. Stange, T. T. Nguyen, F. Mammeri, S. Merash, A. Ponton, Rheological investigation of magnetic sensitive biopolymer composites: effect of the ligand grafting of magnetic nanoparticles, Rheol Acta. 59(3) (2020) 165\u0026ndash;176.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJ. A. Marins, T. Plach\u0026yacute;, P. Kuzhir, Iron\u0026ndash;sepiolite magnetorheological fluids with improved performances, J RHEOL. 63(1) (2019) 125\u0026ndash;139.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eW. I.Kordonski, S. D. Jacobs, Magnetorheological finishing, Int J Mod Phys B. 10(23n24) (1996) 2837\u0026ndash;2848.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eD. N. Miriyala, P. S. Goyal, Effect of MagneticField on the Damping Behavior of a Ferrofluid based Damper, arXiv. 2201 (2022) 09027.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJ. Rabinow, The magnetic fluid clutch, ELECTR ENG. 67(12) (1951) 1167\u0026ndash;1167.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eC. Scherer, A. M. Figueiredo Neto, Ferrofluids: properties and applications, Braz J Phys. 35 (2005) 718\u0026ndash;727.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. S. Kim, Y. D. Liu, B. J. Park, C. Y. You, H. J. Choi, Carbonyl iron particles dispersed in a polymer solution and their rheological characteristics under applied magnetic field, J Ind Eng Chem. 18(2) (2012) 664\u0026ndash;667.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eY. Sun, Y. Wang, H. Deng, M. Sang, X. Gong, Effect of MXene nanosheets attached to carbonyl iron microspheres on the performance and stability of magnetorheological fluid, J Ind Eng Chem. 114 (2022) 508\u0026ndash;517.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eR. C. Bell, J. O. Karli, A. N. Vavreck, D. T. Zimmerman, G. T. Ngatu, N. M. Wereley, Magnetorheology of submicron diameter iron microwires dispersed in silicone oil, Smart Mater Struct. 17(1) (2008) 015028.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eW. L. Zhang, S. D. Kim, H. J. Choi, Effect of graphene oxide on carbonyl-iron-based magnetorheological fluid, IEEE T MAGN. 50(1) (2013) 1\u0026ndash;4.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. N. Aruna, M. R. Rahman, S. Joladarashi, H. Kumar, P. D. Bhat, Influence of different fumed silica as thixotropic additive on carbonyl particles magnetorheological fluids for sedimentation effects, J Magn Magn Mater. 529 (2021) 167910.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eL. Xie, Y. T. Choi, C. R. Liao, N. M. Wereley, Long term stability of magnetorheological fluids using high viscosity linear polysiloxane carrier fluids, Smart Mater Struct. 25(7) (2016) 075006.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eS. Kumar, R. Sehgal, M. F. Wani, M. D. Sharma, Stabilization and tribological properties of magnetorheological (MR) fluids: A review, J Magn Magn Mater. 538 (2021) 168295.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eI. B. Jang, H. B. Kim,J. Y. Lee, J. L. You, H. J. Choi, M. S. Jhon, Role of organic coating on carbonyl iron suspended particles in magnetorheological fluids, J Appl Phys. 97(10) (2005).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eW. H. Chuah, W. L. Zhang, H. J. Choi, Y. Seo, Magnetorheology of core\u0026ndash;shell structured carbonyl iron/polystyrene foam microparticles suspension with enhanced stability, Macromolecules. 48(19) (2015) 7311\u0026ndash;7319.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eW. Jiang, H. Zhu, C. Guo, J. Li, Q. Xue, J. Feng, X. Gong, Poly (methyl methacrylate)-coated carbonyl iron particles and their magnetorheological characteristics, Polymer International. 59(7) (2010) 879\u0026ndash;883.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eK. V. Swaroop, M. N. Aruna, H. Kumar, M. R. Rahman, Rheological characterization of tragacanth gum coated carbonyl particles based magnetorheological fluid, ADVANCES IN MECHANICAL DESIGN, MATERIALS AND MANUFACTURE: Proceeding of the Second International Conference on Design, Materials and Manufacture. (2020) (Vol. 2247, No. 1).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJ. W. Lee, K. P. Hong, S. H. Kwon, H. J. Choi, M. W. Cho, Suspension rheology and magnetorheological finishing characteristics of biopolymer-coated carbonyliron particles, Indus. Eng. Chem. Res. 56(9) (2017) 2416\u0026ndash;2424.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eH. Cheng, M. Wang, C. Liu, N. M. Wereley, Improving sedimentation stability of magnetorheological fluids using an organic molecular particle coating, Smart Mater. Struct. 27(7) (2018) 075030.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eS. G. Belyavskii, P. G. Mingalyov, F. Giulieri, R. Combarrieau, G. V. Lisichkin, Chemical modification of the surface of a carbonyl iron powder, Prot Met+. 42 (2006) 244\u0026ndash;252.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eW. J. Van Ooij, D. Q. Zhu, G. Prasad, S. Jayaseelan, Y. Fu, N. Teredesai, Silane based chromate replacements for corrosion control, paint adhesion, and rubber bonding, Surf Eng. 16(5) (2000) 386\u0026ndash;396.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eY. Joseph, W. Ranke, W. Weiss, Water on FeO(111) and Fe3O4(111): Adsorption Behavior on Different Surface Terminations, J. Phys. Chem. B. 104 (2000) 3224\u0026ndash;3236.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. Breitbach, D. Bathen, H. Schmidt-Traub, Effect of Ultrasound on Adsorption and Desorption Processes, IND ENG CHEM RES. 42 (2003) 5635\u0026ndash;5646.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. P. Merkel, V. L. Dimonie, M. S. El-Aasser, J. W. Vanderhoff, Process parameters and their effect on grafting reactions in core/shell latexes, J Polym Sci Pol Chem. 25(7) (1987) 1755\u0026ndash;1767.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eT. Ai, R. Wang, W. Zhou, Effect of grafting alkoxysilane on the surface properties of Kevlar fiber, Polym Composite. 28(3) (2007) 412\u0026ndash;416.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG. X. Tong, W. H. Wu, Q. Hu, J. H. Yuan, R. Qiao, H. S. Qian, Enhanced electromagnetic characteristics of porous iron particles made by a facile corrosion technique, Mater Chem Phys. 132(2\u0026ndash;3) (2012) 563\u0026ndash;569.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eC. Yin, Y. Cao, J. Fan, L. Bai, F. Ding, F. Yuan, Synthesis of hollow carbonyl iron microspheres via pitting corrosion method and their microwave absorption properties, Appl Surf Sci. 270 (2013) 432\u0026ndash;438.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eQ. Yu, P. Wang, S. Hu, J. Hui, J. Zhuang, X. Wang, Hydrothermal synthesis of hollow silica spheres under acidic conditions, Langmuir. 27(11) (2011) 7185\u0026ndash;7191.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eR. K\u0026ouml;nig, S. M\u0026uuml;ller, R. E. Dinnebier, B. Hinrichsen, P. M\u0026uuml;ller, A. Ribbens, C. Pistidda, The crystal structures of carbonyl iron powder\u0026ndash;revised using in situ synchrotron XRPD, Z Krist-Cryst Mater. 232(12) (2017) 835\u0026ndash;842.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. Jafarian, S. S. S. Afghahi, Y. Atassi, M. Salehi, Enhanced microwave absorption characteristics of nanocomposite based on hollow carbonyl iron microspheres and polyaniline decorated with MWCNTs, J Magn Magn Mater. 462 (2018) 153\u0026ndash;159.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eS. A. B. A. Aziz, S. A. Mazlan, N. A. Nordin, N. A. N. Abd Rahman, U. Ubaidillah, S. B. Choi, N. Mohamad, Material characterization of magnetorheological elastomers with corroded carbonyl iron particles: Morphological images and field-dependent viscoelastic properties, Int J Mol Sci. 20(13) (2019) 3311.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eY. Chen, H. R. Chen, J. L. Shi, Construction of homogenous/heterogeneous hollow mesoporous silica nanostructures by silica-etching chemistry: principles, synthesis, and applications, Accounts Chem Res. 47(1) (2014) 125\u0026ndash;137.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eK. V. Swaroop, M. N. Aruna, H. Kumar, M. R. Rahman, Investigation of steady state rheological properties and sedimentation of coated and pure carbonyl iron particles based magneto-rheological fluids, Mater. Today. 39 (2021) 1450\u0026ndash;1455.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eK. Yang, M. Gu, Enhanced thermal conductivity of epoxy nanocomposites filled with hybrid filler system of triethylenetetramine-functionalized multi-walled carbon nanotube/silane-modified nano-sized silicon carbide, Compos. Part A: Appl. Sci. Manuf. 41(2) (2010) 215\u0026ndash;221.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eG. Liu, Y. Chen, M. Gong, X. Liu, Z. K. Cui, Q. Pei, J. G, C. Huang, Q. Zhuang, Enhanced dielectric performance of PDMS-based three-phase percolative nanocomposite films incorporating a high dielectric constant ceramic and conductive multi-walled carbon nanotubes, J. Mater. Chem. C. 6(40) (2018) 10829\u0026ndash;10837.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eK. Jiao, C. Zhou, N. Becerra-Mora, J. Fiske, P. Kohli, Vapor-enhanced covalently bound ultra-thin films on oxidized surfaces for enhanced resolution imaging, J. Mater. Chem. C. 4(37) (2016) 8634\u0026ndash;8647.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eN. L. Burhannuddin, N. A. Nordin, S. A. Mazlan, S. A. A. Aziz, N. Kuwano, S. K. M. Jamari, Physicochemical characterization and rheological properties of magnetic elastomers containing different shapes of corroded carbonyl iron particles, Sci. Rep. 11(1) (2021) 868.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eV. V. Gorodov, S. A. Kostrov, R. A. Kamyshinskii, E. Y. Kramarenko, A. M. Muzafarov, Modification of carbonyl iron particles by carboxyl-containing polydimethylsiloxanes, Russian Chem. Bull. 67 (2018) 1639\u0026ndash;1647.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eP. Zhao, T. Du, N. Ma X. Dong, M. Qi, Effect of interfacial shear strength between magnetic particles and carrier liquid on rheological properties of magnetorheological fluids, J Mol Liq. 369 (2023) 120929.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eZ. Feng, L. Yi, R. Hongjuan, Study of sedimentation stability of magnetorheological fluid, Adv. Mat. 4(1) (2015) 1\u0026ndash;5.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eA. Ronzova, M. Sedlacik, M. Cvek, Magnetorheological fluids based on core\u0026ndash;shell carbonyl iron particles modified by various organosilanes: synthesis, stability and performance, Soft Matter. 17(5) (2021) 1299\u0026ndash;1306.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eT. Plachy, M. Cvek, L. Munster, B. Hanulikova, P. Suly, A. Vesel, Q. Cheng, Enhanced magnetorheological effect of suspensions based on carbonyl iron particles coated with poly(amidoamine) dendrons, Rheol. Acta. 60(5) (2021) 263\u0026ndash;276.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eM. Cvek, M. Mrlik, R. Moucka, M. Sedlacik, A systematical study of the overall influence of carbon allotrope additives on performance, stability and redispersibility of magnetorheological fluids, Colloid Surface A. 543 (2018) 83\u0026ndash;92.\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Enhancement of coating effect, Carbonyl iron particle, Etching by hydrochloric acid, Magnetorheological fluid, Dispersion stability","lastPublishedDoi":"10.21203/rs.3.rs-4052080/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4052080/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThe coating effect of 1,2-bis(triethoxy-silyl)ethane (BTES) on the carbonyl iron particles (CIP) was enhanced through the etching of CIP by adjusting the concentration of hydrochloric acid (HCl), leading to a significant improvement in the dispersion stability of the magnetorheological fluid (MRF). The microstructures, coating effect and magnetism of the CIPs were examined using the scanning electron microscopy (SEM), automatic surface and porosity analyzer (BTE), fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA) and vibrating sample magnetometer (VSM). Furthermore, the rheological properties and dispersion stability of the MRFs were assessed using a rotating rheometer and turbiscan-tower. The results shown that with the concentration of HCl increased, the nanopores appeared on the CIPs and then disappeared, and the specific surface area of the particles increased and then decreased. The number of nanopores sharply increased and the specific surface area of particles sharply increased to 37.7697 m\u003csup\u003e2\u003c/sup\u003e/g when the concentration of HCl reached to 0.50 mol/L. As the concentration of HCl increased, the coated mass of BTES on the particles increased. The coated mass loss was less than 1 wt.% when the concentration of HCl was below 0.50 mol/L, and the coated mass loss increased to 2.45 wt.% when the concentration of HCl was 0.5 mol/L, the coated mass was effectively enhanced by the HCl of higher concentration. As the concentration of HCl increased, the saturation magnetization of particles decreased, and a sharply decrease appeared when the concentration of HCl was 0.50 mol/L, the saturation magnetization of coated particles further decreased from 196.7 emu/g to 113.3 emu/g. As the coated mass of particles increased, the viscosity and shear stress of MRFs increased and the increase was significant when the coated mass loss of particles above 2.45 wt.% without a magnetic field, while which decreased under a magnetic filed. As the coated mass of particles increased, the sedimentation rate of particles decreased from 0.13 to 0.01 mm/h, when the coated mass loss of particles was more than 2.45 wt.%, the sedimentation rate of all MRFs were close to 0.01 mm/h. The coating effect was greatly enhanced by controlling the concentration of HCl, and thus the MRF with superior shear stress and excellent dispersion stability was obtained.\u003c/p\u003e","manuscriptTitle":"The enhanced coating effect of carbonyl iron particles and improved dispersion stability of magnetorheological fluid","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-03-27 08:49:05","doi":"10.21203/rs.3.rs-4052080/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ddb6f0d2-99cd-4ecc-936f-948608ed78f6","owner":[],"postedDate":"March 27th, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":29940769,"name":"Physical sciences/Chemistry/Materials chemistry"},{"id":29940770,"name":"Physical sciences/Chemistry/Materials chemistry/Magnetic materials"}],"tags":[],"updatedAt":"2024-04-23T07:34:10+00:00","versionOfRecord":[],"versionCreatedAt":"2024-03-27 08:49:05","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4052080","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4052080","identity":"rs-4052080","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}