Preparation of UiO-66-NH 2 /MgAl-LDHs @ Sodium Alginate Fiber Membrane and Determination of Oil Water Separation Performance

Preparation of UiO-66-NH 2 /MgAl-LDHs @ Sodium Alginate Fiber Membrane and Determination of Oil Water Separation Performance | 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 Research Article Preparation of UiO-66-NH 2 /MgAl-LDHs @ Sodium Alginate Fiber Membrane and Determination of Oil Water Separation Performance Hongmei Wang, Jiawen Zhang, Zhenggang Wang, Shuang Hu, Zhuang Fu, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6820860/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 03 Dec, 2025 Read the published version in Cellulose → Version 1 posted 4 You are reading this latest preprint version Abstract Oil spills and waste oil discharges generate vast quantities of oily wastewater, posing severe ecological and environmental challenges while also endangering human health, which necessitates the development of advanced and efficient oil-water separation membranes. In this work, a novel sodium alginate fiber (SA) based superhydrophilic/underwater superoleophobic (SUS) membrane was developed for o/w separation through a facile method by blending SA nanofibers with UiO-66-NH 2 /MgAl-LDH cluster-assembled microsphere. The micron-scale spheres were embedded within SA nanofibers, inducing the formation of a loosely stacked nanofiber structure, thereby enhancing water permeability. The obtained composite membrane exhibited good o/w separation performance with a high separation efficiency of >99% and a flux rate of ~2661 L m -2 h -1 . Moreover, The underwater oil contact angle (OCA) of U-LDHn@SA composite membrane were all around 140°, which indicated that U-LDHn@SA composite membrane has good underwater superoleophobicity. After 10 cycles, the oil-water separation efficiency exceeded 99% and the water flux always exceeds 2021 L m -2 h -1 . The compose membrane also exhibited the potential to separate oil-in-water emulsion with the highest oil rejection of 94%. The membrane showed antifouling properties, recyclability, and stability in harsh conditions. This work provides a new idea for the development of oil-water separation membranes with practical applications. Sodium alginate fibre Layered double hydroxide material UIO-66-NH2 Oil-water separation Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Introduction Oil spills and waste oil discharges produce large quantities of oily wastewater, which not only causes serious ecological and environmental problems but also threatens human health (Li, et al. 2019 ; Liu, et al. 2019 ; Xie, et al. 2020 ). Consequently, there is a pressing need to develop effective measures to address the issues related to oily wastewater. There are many o/w separation technologies such as coagulation, flotation, membrane separation, absorption, and centrifugation (Huang, et al. 2019 ; (Wu, et al. 2020 ; Xie, et al. 2020 ; Zheng, et al. 2020 ). Among these methods, membrane separation technology offers a number of advantages, including simple operation, low cost, and the absence of secondary pollution (Yang, et al. 2021 ). These attributes make it an attractive option for the treatment of oily wastewater. Thus, there has been an increased focus on the study of superhydrophilic underwater superoleophobic (SUS) membranes (Yue, et al. 2019 ; Zhang, et al. 2014 ). Biomass materials, such as cellulose, chitosan, and wood, have garnered significant attention due to their distinctive spatial structure and the presence of numerous active functional groups (Zhang, et al. 2023 ). Sodium alginate (SA) is a pervasive marine biopolymer derived from the cellular structure of various brown algae (Liu, et al. 2019 ). Due to the presence of its oxygen-containing functional groups (-COOH, -OH, etc.), sodium alginate has been utilized as a hydrophilic membrane matrix (Ehsan, et al. 2023 ). In the realm of membrane technologies for oil-water separation, an efficacious strategy to bolster both the flux and overall performance involves the strategic integration of hydrophilic particles within the membrane matrix. This approach serves a dual function: it not only regulates the pore size of the membrane but also changes the surface morphology to increase the roughness, which significantly increases the hydrophilicity of the membrane surface (Wahid, et al. 2021 ). MOFs are characterized by their high porosity, large specific surface area, and adjustable pore size, as well as their clear molecular adsorption sites (Awwad, et al. 2023 ; Elrasheedy, et al. 2019 ; Yu, et al. 2021 ). These properties have led to the use of MOF in a variety of applications, including gas separation (Daglar, et al. 2020), energy conversion (Wang, et al. 2018 ), and metal ion adsorption (Ihsanullah. 2022). Notably, UiO-66-NH 2 has emerged as a particularly promising material, exhibiting remarkable heat resistance, high water stability, and substantial adsorption capacity (Shen, et al. 2022 ). Consequently, the utilization of UiO-66-NH 2 has been extended to the surface modification of oil-water separation membranes. And the functional group (-NH 2 ) in UiO-66-NH 2 can be utilized to introduce hydrophilic modifications to the membrane (Zhu, et al. 2021 ). Layered double hydroxides are classified as anionic layered compounds. LDH possesses a distinctive structural configuration, characterized by an abundance of hydroxyl groups situated between the layers and on the material's surface. The layered double hydroxide (LDH) material possesses a number of advantageous properties, including a substantial specific surface area, adequate porosity, and a stable layer structure (Everaert, et al. 2018 ; Kameda, et al. 2019 ; Tahsiri, et al. 2022 ). The MgAl-LDH nanosheets exhibit a micrometer-sized morphology, yet possess a thickness measured in nanometers (Cao, et al. 2021 ; Iqbal, et al. 2020 ; Yang, et al. 2022 ). This structural characteristic is particularly conducive to the loading of nanoscale UiO-66-NH 2 onto the LDH nanosheets, thereby augmenting the overall dimensions of the particles, and further increase the hydrophilicity of the membrane surface at the same time (Guo, et al. 2018 ; Long, et al. 2017 ; Lu, et al. 2023 ). In light of the aforementioned findings, sodium alginate fiber was selected as the substrate for the construction of superhydrophilic films aimed at facilitating oil-water separation in this study. The pore structure of the hydrophilic membrane was modified through the incorporation of UiO-66-NH 2 /MgAl-LDH cluster-assembled microsphere, aiming to elucidate its correlation with the oil-water separation efficacy of the film. The morphology of the membrane was characterized by XPS, SEM, and AFM etc. And the separation performance was characterized by separation flux, separation efficiency, and oil cut-off rate. This research will provide an approach for designing multifunctional membranes for o/w separation. Experimental 2.1 Materials The sodium alginate raw material for the preparation of sodium alginate fiber was obtained from Yantai Hongri Biotechnology Co. Dopamine hydrochloride (C 8 H 11 NO 2 ·HCl), zirconium chloride (ZrCl 4 ), 2-aminoterephthalic acid (C 8 H 7 NO 4 ), magnesium nitrate hexahydrate (Mg(NO 3 ) 2 ·6H 2 O), aluminum nitrate hydrate (Al(NO 3 ) 3 ·9H 2 O), urea (CH 4 N 2 O), Sudan Ⅲ were obtained from Shanghai Macklin Biochemical Technology Co. Ltd, concentrated ammonia, N,N-dimethylformamide (DMF), methanol were of analytical grade. 2.2 Preparation of sodium alginate fibre 955 g of deionised water was added to 45 g of sodium alginate raw material weighed in advance, which was then stirred at 80 °C for 1 h to obtain 1000 g of sodium alginate solution with a concentration of 4.5%. The solution was defoamed by centrifugation at 10000 rpm for 10 mi n at 50 ℃ to obtain the sodium alginate solution for spinning, which was loaded into a stainless steel storage tank with an insulated jacket (the temperature of the jacketed insulated water was 50 ℃). The sodium alginate solution was pressurised with compressed air through a spinneret nozzle with a diameter of 0.05 mm × 800 holes into a coagulation bath consisting of a 5 wt% aqueous solution of calcium chloride at a bath temperature of 25 ℃. The regenerated fibres were subjected to a series of processes, including drawing, washing and oiling, to obtain sodium alginate fibres in a wet state. Subsequently, the wet fibre was placed in a refrigerator at -80 ℃ for 4 h, after which the frozen wet fibre was freeze-dried to obtain the final sodium alginate fibre. 2.3 Preparation of U-LDHn cluster-assembled microsphere MgAl-LDHs were prepared through a solvothermal method. Typically, 0.02 mol of Mg(NO 3 ) 2 ·6H 2 O and 0.01 mol of Al(NO 3 )·9H 2 O were added to 100 mL of deionised water. Then, 6 g of urea were added into the solution under continuous stirring for 5 min. The mixed solution was transferred to a 100 mL stainless steel hot press kettle and stored for 24 h at 110 ℃(Xu, et al. 2005; Dong, et al. 2019). The solid product obtained was collected by centrifugation and washed three times with deionised water to remove excess reactants. The sample obtained was baked in a vacuum drying oven at 60 ℃ for 12 h. Different weight (0.05 g, 0.15 g, 0.25 g, 0.35 g, 0.45 g) of MgAl-LDHs were added to 50 mL of DMF, which were stirred for 30 min, respectively. Then, 0.2332 g of ZrCl 4 and 0.1812 g of H 2 BDC-NH 2 were added to the above solutions, which were stirred for 1 h to allow for full dissolution. The mixed solution was transferred to a 100 mL stainless steel autoclave and stored at 120 ℃ for 48 h(Li, et al. 2019). The solid product was collected by centrifugation and washed 6 times with methanol to remove excess reactants. The resulting sample was baked in a vacuum oven at 80 ℃ for 12 h. The obtained scluster-assembled microsphere was coded as U-LDH 1 , U-LDH 2 , U-LDH 3 , U-LDH 4 and U-LDH 5 , which different content of MgAl-LDHs were 12.5%, 30.0%, 41.7%, 50.0%, and 56.3%, respectively. 2.4 Fabrication of superhydrophilic membrane Sodium alginate was crushed to powder using a crusher, then 0.5 g of the scluster-assembled sphere U-LDHn and 0.6 g of sodium alginate fibres were weighed and dispersed in deionised water to give 45 g of suspension. Dilute ammonia was added to the above suspension to adjust the pH of the suspension to 8.5. After sonication for 30 min, 0.7 g of dopamine hydrochloride was weighed and dissolved in 15 mL of deionised water and the dopamine hydrochloride solution was added to the above suspension which was stirred at 30 ℃ for 24 h(Liao, et al. 2017). Finally, 15 g of the suspension was weighed and then vacuum filtration onto cellulose acetate filter paper (the effective area of the cellulose acetate filter paper was 2.54 cm -2 ), and then dried under vacuum at 45 ℃ for 4 h. 2.5 Characterization A Fourier transform infrared spectrometer (FTIR) (Avatar-360, USA) was used to study the chemical structure of the synthesized particles and membranes. The wave number range of all spectra was 4000 cm -1 to 400 cm -1 .XRD analyses were performed using a D8 ADVANCE Ultra Front Diffractometer with a scan rate of 4° min -1 in the 2θ range of 5~80°. Microscopic analyses of the samples were performed using a ZEISS-Gemini SEM 500 (Germany), and all samples were sprayed with gold prior to microscopic observation. Atomic force micro-scopy (AFM, Bruker) was applied to investigate the surface roughness from a membrane area of 15 μm × 15 μm in tapping mode. The surface composition of the membranes was studied by X-ray photoelectron spectroscopy (XPS, AXIS SUPRA+). Thermogravimetric analysis of the composite membranes was carried out using an NETZSCH/STA449F5 thermogravimetric analyzer. The samples were placed in a TGA sample cup and heated from room temperature to 800 ℃ at a heating rate of 10 ℃ min -1 . Surface properties such as surface area, pore volume and pore diameter were measured using a Bruauer - Emmet - Teller (BET) analyser (JW-BK100). The surface wettability of the membranes was investigated using a SDC-80 contact angle meter. 2.6 Oil/water separation The U-LDHn@SA membrane was wetted by water, then the wetted membrane was sandwiched between two Teflon flanges. The oil/water mixture can be prepared by mixing synthetic ester oil, transformer oil, dichloromethane into water (20 mL, V oil /V water =1/1), and then slowly pouring it into the separation apparatus. The separation efficiency ( η ) is calculated by the following equation(Pan, et al. 2008)： where J represents flux (L m -2 h -1 ), V represents the filtrate volume (L), S represents the effective area (m 2 ), ∆ t represents the separating time (h). For emulsion separation, 10 mL of oil was mixed with 490 mL water, followed by the addition of Tween-80 (0.05 g) and sonicated for 3 h to obtain a stable oil-in-water emulsion. The prepared emulsion was added into the upper receiver of the filtration equipment and negative pressure of <0.1 bar was applied to separate the emulsion. The con­centration of the oil in pure emulsion and filtrates was measured by a UV–vis spectrometer (λ = 340 ~ 600) and the oil rejection percentage was calculated by the Eq(Jiang JingXian, et al. 2019): Where C 0 and C f are the concentrations of oil in the pure emulsion and filtrates, respectively. 2.7 Reusability and stability The wettability of the membrane was determined by measuring the contact angle of water and oil on the membrane at room temperature. The water contact angles (WCA) of samples were measured with an SDC-80 static contact angle analyzer at 25 °C. The same method was used to determine the oil contact angle (OCA) underwater. The adhesion of the oil is observed by repeatedly contacting the membrane surface with the oil droplets. 2.8 Data analysis At least three repeat times were set up during the test and the data were presented as "mean ± standard deviation" (n = 3). Results and discussion 3.1 Characterization of U-LDHn @ SA composite Membrane The surface morphologies of the pure SA membrane, and the composite membranes U-LDHn@SA are shown in Fig. 1. As illustrated in Fig. 1a, the pure SA membrane exhibits a homogeneous surface morphology, primarily composed of aggregated sodium alginate fibers. These fibers are densely packed, forming a compact membrane structure that will impede water permeation. The dense architecture of the SA membrane is likely attributed to the formation of intermolecular hydrogen bonds between closely aligned fibers, which undergo irreversible structural changes upon drying. As shown in Fig.1c 2 , the synthesized pure MgAl-LDHs are smooth hexagonal sheet structures and the size of individual MgAl-LDHs nanosheets can reach up to 2 μm, with a thickness of only nanoscale, which makes it easy to attach UiO-66-NH 2 nanoparticles (Fig. S1 and S2). The morphology of pure UiO-66-NH 2 is more regular spheres, and its particle sizes range from 50 to 200 nm(Zhu, et al. 2021). As shown in Fig. 1c 1 , UiO-66-NH 2 was successfully loaded onto MgAl-LDHs and the two were clustered together, resulting in the overall size of the U-LDHn clustered microspheres being increased from the nanometer scale to the micrometer scale. The micrometer-sized U-LDHn cluster-assembled microspheres were further embedded within SA nanofibers, resulting in a roughened surface morphology of the U-LDHn@SA composite membrane. This unique encapsulation method can induce the formation of loosely stacked nanofiber structures, which can improve water permeability. Increasing the amount of MgAl-LDHs increases the hexagonal lamellar structure in the clustered U-LDHn as shown in Fig. 1b and 1d. EDS has been used to characterize elemental distribution on the surface of the composite Membrane U-LDH 3 @SA, respectively. As illustrated in Fig. 1e, the EDS has been mapped from Fig. 1c 1 , demonstrated the present of Mg, Al, and Zr elements, and are uniformly distributed on the membrane surface. The FTIR spectra of MgAl-LDHs, UiO-66-NH 2 and U-LDHn are shown in Fig.2a. The main characteristic peaks of U-LDHn were almost identical to those of pure UiO-66-NH 2 . The peaks located at 3462 and 3355 cm -1 are asymmetric and symmetric stretching vibrations of the -NH 2 group, and the signal at 1585 cm -1 is due to -COOH and Zr 4+ coordination(Li, et al. 2022). These results indicated that the successful introducing of UiO-66-NH 2 to U-LDHn. The characteristic peak at 771 cm -1 can be attributed to Al-OH vibrations, which suggest the presence of MgAl-LDHs in the composites(Yousefzadeh, et al. 2024). XRD analysis of UiO-66-NH 2 , MgAl-LDHs, U-LDHn were also conducted to investigate the synthesis of U-LDHn. As illustrated in Fig.2b, the XRD spectra of U-LDHn exhibit distinctive diffraction peaks of UiO-66-NH 2 at 7.1°, 8.1° which correspond to the (111), (002) crystal planes, respectively(Zhao, et al. 2020). The presence of MgAl-LDHs was observed as relatively weak signals on the XRD patterns of U-LDHs, with the most prominent peak occurring at 12.21°(Ma, et al. 2011). This phenomenon can be attributed to the particles of UiO-66-NH 2 covering the MgAl-LDHs, thereby obscuring the signal (Fig. S3). In summary, the results of IR and XRD spectroscopy indicate that the synthesis of U-LDHn was successful. The thermal characteristics of pure SA membranes and U-LDHn@SA composite membranes were evaluated using thermogravimetric analysis. As shown in Fig. 2c, three phases of weight loss were observed for the samples, the weight loss in the first phase (40-240 ℃) was mainly caused by the evaporation of adsorbed water on the surface of the samples. The detachment of the hydroxyl-containing groups of the material and the decomposition of the carbonate ions of LDH lead to the weight loss in the second stage (240-380 ℃)(Yang, et al. 2012; Fernández, et al. 1998). At temperatures above 380 ℃, the hydrophilic ligand 2-aminoterephthalic acid, a component of UiO-66-NH 2 , also begins to decompose(Garibay, et al. 2010). When the temperature reached 800 ℃, the total weight loss was 54% for pure SA and 47% for the composite membrane U-LDH 1 @SA. By further increasing the ratio of MgAl-LDH instead, the thermal stability of the membrane was weakened. The total weight loss of the composite membrane U-LDH 5 @SA reaches 60%, indicating that the higher content of hydrophilic groups in the composite material improves the hydrophilicity of the material. In order to analyze the chemical structure of the membrane surface, XPS analysis of the composite membrane was carried out (Fig. 3). The full-spectrum scan illustrated the presence of C, O, N, Mg, Al, and Zr, which was consistent with the EDS results. The peaks at 401.8 eV and 399.9 eV in the N 1s pattern correspond to C−N and N−H. Within the context of the Zr 3d pattern, the spectral peaks manifested at binding energies of 182.4 eV and 184.9 eV can be ascribed to the Zr 3d 5/2 orbitals(Su, et al. 2017). In the Al 2p spectrum, the characteristic peak centered at 75.3 eV is attributed to the Al−O chemical bonding. Combining the above characterizations that MgAl-LDHs with UiO-66-NH 2 were successfully prepared and loaded onto sodium alginate fibers(Chen, et al. 2020). In the C 1s spectrum, the signals at 284.8 eV, 286.6 eV, and 288.4 eV correspond to C−C, C−O−C, and O−C=O bonds, respectively, which may be related to the structure of sodium alginate as well as to the formation of PDAs by self-polymerization of dopamine HCl. 3.2 Surface wettability Surface wettability is a pivotal factor in assessing the oil-water separation efficiency of membranes, given its potential impact on the permeation flux and antifouling properties of the membrane. Thus, the contact angle was measured in both air and underwater environments. In the air, the drop of water immediately was spread on the SA membrane surface and forming an angle of 45.3º (Fig. 4a). This observation indicates that the SA membrane is hydrophilic, this may attributable to the abundance of hydroxyl-containing groups on the surface of membrane. When the water droplet contacted the U-LDH 3 @SA composite membrane, it spread rapidly, resulting in a contact angle of zero degrees (Fig. 4a and Movie S1). The results demonstrated that the U-LDH 3 -modified, the U-LDHn@SA composite membrane exhibits superhydrophilic properties, facilitated to the application of oil-water separation. Subsequently, the underwater OCA of U-LDHn@SA composite membranes was evaluated by fire-resistant oil. The underwater OCA were all around 140º for U-LDHn@SA composite membranes (Fig. 4b). To further investigate the self-cleaning and anti-fouling performance of the U-LDHn@SA composite membrane, a dynamic oil wetting test was performed on the membrane. As depicted in Movie S2, an oil droplet (fire-resistant oil) contacted and then left the surface of the membrane in an aqueous environment. After complete contact with the U-LDHn@SA membrane surface, when the droplet upward lift, no discernible deformation was observed upon its departure from the membrane surface. These observations suggest that the composite membrane possesses underwater superoleophobic properties. Notably, as illustrated in Fig. 4c and 4d, the Ra values of the pure SA film and the U-LDHn@SA composite film were 49.3 and 89.3, respectively. The Ra of the composite membrane after the incorporation of U-LDHn cluster spheres exceeds twice that of the pure SA membrane. The surface wettability of a membrane increases with the roughness of the surface. Therefore, PDA and U-LDHn cluster-assembled microspheres improve the porosity and hydrophilicity of the membrane(Wen, et al. 2018). 3.3 Oil/water separation The separation performance of the composite membrane with an effective area of 2.54 cm 2 was investigated by using o/w mixture (transformer oil/water). The membrane was wetted in water for 2 min and fixed with a clip between two glass tubes (Fig. 5a). The oil and water mixture were added into the upper tube of the filtration device. As depicted in Fig. 5a, the U-LDHn@SA membrane exhibited a rapid permeation of the water and collected in a flask while the oil could not pass through the superhydrophilic membrane and was collected from the upper part of the tube. In contrast, when pure SA membrane was used, a single droplet of water could not pass through the membrane even a high negative pressure of 1.0 bar was applied for 3 min. The impermeability of the SA membrane may be due to the tight fiber arrangement, smooth surface, and small pore size (Fig. S4). As shown in Fig. 5b, the permeate flux of U-LDH 1 @SA membrane was 832.4 L m -2 h -1 with high separation efficiency above 98%. The separation flux U-LDH @SA membrane increased to 2661 L m -2 h -1 with the MgAl-LDH content increased from 12.5% to 41.7%. However, the separation flux decreased significantly to 809.7 L m -2 h -1 when MgAl-LDHs increased to 56.3%. These may because when the MgAl-LDH content is extremely low, the main constituents within the hydrophilic particle are small-sized UiO-66-NH 2 . The pores in the composite membrane were covered by an excess of small-sized UiO-66-NH 2 , which results in a reduction of the overall porosity of the membrane. When the MgAl-LDH content increased to 41.7%, the overall particle size of the U-LDHn cluster-assembled microsphere increased, which further led to a loosening of the fiber arrangement within the membrane, which increased the composite membrane's porosity, thus increased the separation flux. However, as the MgAl-LDH content increased to 56.3%, the excessive MgAl-LDH micrometer-scale laminae obscured the pore space that the U-LDHn cluster-assembled microsphere made the membrane appear, leading to a decrease in the separation flux. In addition, several other o/w mixtures containing different oils such as synthetic ester oils, transformer oils, and methylenechloride were tested for separation using the U-LDH 3 @SA composite membrane. It has been demonstrated that composite membranes consistently demonstrate high separation fluxes for low relative molecular mass oils (synthetic ester oils and transformer oils) of around 2565 L m -2 h -1 and relative low separation fluxes for high molecular mass oils (dichloromethane) of around 1988 L m -2 h -1 . 3.4 Recyclability, stability, and antifouling properties of the membrane In order to examine the recyclability of the membrane, the U-LDH 3 @SA membrane were also subjected to cyclic separation tests. As depicted in Fig. 6a, the membrane exhibited separation of o/w mixture after 10 cycles. The separation flux decreased as the number of cycles increased, it may be because the membrane surface or pores absorbed much oil. Nonetheless, the separation efficiency of the membrane was essentially stabilized at 99%, and the separation flux was stabilized at approximately 2021 L m -2 h -1 . The above results proved that U-LDH 3 @SA membrane has superior antifouling ability and excellent reusability. To evaluate the chemical stability of the U-LDH 3 @SA composite membrane, the transformer oil was separated from different pH water (pH = 1.0 and 12.0) and 0.1 M NaCl solution (Fig. 6b). As shown in Fig. 6c, at pH = 12 a brown colored solution was collected in the receiving flask. It is possible that trace amounts of PDA molecules were eliminated during the washout process. The acid and salt solutions had no significant effect on the morphology of the composite membranes. Thus, the U-LDHn@SA membrane can be used to treat oily wastewater under weak acid, weak/medium alkaline, and saline conditions. To verify the anti-fouling and self-cleaning capability of the U-LDH 3 @SA membrane, underwater anti-fouling tests were conducted. As shown in Fig. 6d and Movie S3 the membrane was immersed in the water and tried to foul with the flow of oil, the oil rapidly slid off despite hitting the membrane with a high flow rate. Moreover, when the membrane was tried to immerse in the water/fire-resistant oil mixture, it was found to float on the oil-water interface and was clear after soaking in the oil. This entire experiment showed that the membrane possessed strong antifouling and self-cleaning ability, which could be a promising material for o/w separation. 3.5 Oil-in-water emulsion separation In comparison with o/w mixtures, o/w emulsions are challenging to treat due to their good stability and micro dimensions(Wang, et al. 2015). In this work, several o/w emulsions (transformer oil, synthetic ester oil and fire-resistant oil) were prepared and the separation performance of U-LDH 3 @SA composite membrane was investigated. As shown in Fig. 7a, the low viscosity and light oil emulsion (transformer oil) exhibited highest oil rejection percentage of 94.2%, and the oil rejection percentage of the high viscosity and heavy oil emulsions (fire-resistant oil) were slightly lower, but also higher than 92%. When the oil emulsion approached the membrane surface during the separation process, it could easily detach back to the feed emulsion due to the non-sticky property of the superhydrophilic and underwater superoleophobic membrane. (Fig. 7d) (Zhong, et al. 2023). The DLS graphs, photographs, and optical microscopic images of feed and filtrate are shown in Fig. 7b and 7c (Synthetic ester oil as an example). The original emulsion was milky white in color with a wider droplet size distribution ranging from 51 nm to 8825 nm, while the filtrate was transparent in color with large oil droplets are almost non-existent only small droplets are present. The DLS plot of the filtrate only observed a strong peak in the range of 31 ~ 270 nm, which may be due to the presence of emulsifier. The results indicated that the composite membrane show good separation performance on oil-in-water emulsion separation. Conclusion In summary, a novel SUS membrane was designed by the blending of SA nanofibers with UiO-66-NH2/MgAl-LDH cluster-assembled microsphere, followed by self-polymerization of bioinspired PDA. PDA and U-LDHn cluster-assembled microspheres improve the Ra of the membrane, thus increasing the surface hydrophilicity. The obtained SUS membrane can efficiently separate oil/water mixtures with a high o/w separation efficiency of 99%, with a flux rate of 2661 L m − 2 h − 1 by applying a negative pressure of 0.1 bar. After 10 cycles, the oil-water separation efficiency exceeded 99%, and the water flux always exceeded 2021 L m − 2 h − 1 . In addition, the composite membrane has excellent chemical stability, self-cleaning, and anti-fouling properties. Moreover, the membrane showed high oil-in-water emulsion separation efficiency with the oil rejection percentage of 94.2%. This study presents a novel UiO-66-NH 2 /MgAl-LDH@SA composite membrane, offering valuable insights for the treatment of oily water pollution. Declarations Author contributions Jiawen Zhang and Zhenggang Wang wrote the main manuscript text, Jiawen Zhang prepared all figures . Honmei Wang, Jingfeng Zhang and Xichao Liang reviewed the manuscript. Zhuang Fu and Shuang Hu made substantial contributions to the conception and design of the work. Funding This work was supported by the Natural Science Foundation supported by Hunan Province [grant numbers 2024JJ6027], Hunan Provincial Department of Education Scientific Research Key Project [grant numbers 23A0269], and Changsha University of Science and Technology Graduate Student Research Innovation Project [grant numbers CLKYCX24073]. Data availability Data is provided within the manuscript or supplementary information files. Declarations Conflict of interest The authors declare no competing interests. Human and animal rights We declare that no experiments on animal or human participants were conducted in the study. Consent for publication The authors have agreed to submit the manuscript to the journal. References Y. Li, H. Zhang, C. Ma, H. Yin, L. Gong, Y. Duh, R. Feng, Durable, cost-effective and superhydrophilic chitosan-alginate hydrogel-coated mesh for efficient oil/water separation, Carbohydrate polymers, 226(2019) 115279. Y. Liu, X. Wang, S. Feng, Nonflammable and magnetic sponge decorated with polydimethylsiloxane brush for multitasking and highly efficient oil–water separation, Advanced Functional Materials, 29(2019) 1902488. A. Xie, J. Cui, J. Yang, Y. Chen, J. Lang, C. Li, Y. Yan, J. Dai, Graphene oxide/Fe (III)-based metal-organic framework membrane for enhanced water purification based on synergistic separation and photo-Fenton processes, Applied Catalysis B: Environmental, 264(2020) 118548. Y. Huang, H. Zhan, D. Li, H. Tian, C. Chang, Tunicate cellulose nanocrystals modified commercial filter paper for efficient oil/water separation, Journal of Membrane Science, 591(2019) 117362. W. Zheng, J. Huang, S. Li, M. Ge, L. Teng, Z. Chen, Y. Lai, Advanced materials with special wettability toward intelligent oily wastewater remediation, ACS Applied Materials & Interfaces, 13(2020) 67-87. M. Wu, P. Mu, B. Li, Q. Wang, Y. Yang, J. Li, Pine powders-coated PVDF multifunctional membrane for highly efficient switchable oil/water emulsions separation and dyes adsorption, Separation and Purification Technology, 248(2020) 117028. A. Xie, J. Cui, J. Yang, Y. Chen, J. Lang, C. Li, Y. Yan, J. Dai, Photo-Fenton self-cleaning PVDF/NH2-MIL-88B (Fe) membranes towards highly-efficient oil/water emulsion separation, Journal of Membrane Science, 595(2020) 117499. J. Yang, J. Cui, A. Xie, J. Dai, C. Li, Y. Yan, Facile preparation of superhydrophilic/underwater superoleophobic cellulose membrane with CaCO3 particles for oil/water separation, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 608(2021) 125583. X. Yue, Z. Li, T. Zhang, D. Yang, F. Qiu, Design and fabrication of superwetting fiber-based membranes for oil/water separation applications, Chemical Engineering Journal, 364(2019) 292-309. W. Zhang, Y. Zhu, X. Liu, D. Wang, J. Li, L. Jiang, J. Jin, Salt‐induced fabrication of superhydrophilic and underwater superoleophobic PAA‐g‐PVDF membranes for effective separation of oil‐in‐water emulsions, Angewandte Chemie International Edition, 53(2014) 856-60. W. Zhang, Y. Liu, F. Tao, Y. An, Y. Zhong, Z. Liu, Z. Hu, X. Zhang, X. Wang, An overview of biomass-based Oil/Water separation materials, Separation and Purification Technology, 316(2023) 123767. J. Liu, R. Zhang, M. Ci, S. Sui, P. Zhu, Sodium alginate/cellulose nanocrystal fibers with enhanced mechanical strength prepared by wet spinning, Journal of Engineered Fibers and Fabrics, 14(2019) 1558925019847553. M. Ehsan, H. Razzaq, S. Razzaque, M. Kanwal, I. Hussain, Engineering nanocomposite membranes of sodium alginate-graphene oxide for efficient separation of oil-water and antifouling performance, Journal of Environmental Chemical Engineering, 11(2023) 109185. F. Wahid, X.-J. Zhao, Y.-X. Duan, X.-Q. Zhao, S.-R. Jia, C. Zhong, Designing of bacterial cellulose-based superhydrophilic/underwater superoleophobic membrane for oil/water separation, Carbohydrate Polymers, 257(2021) 117611. M. Awwad, M. Bilal, M. Sajid, M.S. Nawaz, I. Ihsanullah, MOF-based membranes for oil/water separation: Status, challenges, and prospects, Journal of Environmental Chemical Engineering, 11(2023) 109073. S. Yu, H. Pang, S. Huang, H. Tang, S. Wang, M. Qiu, Z. Chen, H. Yang, G. Song, D. Fu, Recent advances in metal-organic framework membranes for water treatment: A review, Science of the Total Environment, 800(2021) 149662. A. Elrasheedy, N. Nady, M. Bassyouni, A. El-Shazly, Metal organic framework based polymer mixed matrix membranes: Review on applications in water purification, Membranes, 9(2019) 88. H. Daglar, S. Keskin, Recent advances, opportunities, and challenges in high-throughput computational screening of MOFs for gas separations, Coordination Chemistry Reviews, 422(2020) 213470. L. Wang, M. Zheng, Z. Xie, Nanoscale metal–organic frameworks for drug delivery: a conventional platform with new promise, Journal of Materials Chemistry B, 6(2018) 707-17. I. Ihsanullah, Applications of MOFs as adsorbents in water purification: Progress, challenges and outlook, Current Opinion in Environmental Science & Health, 26(2022) 100335. S. Shen, Y. Shen, Y. Wu, H. Li, C. Sun, G. Zhang, Y. Guo, Surface modification of PVDF membrane via deposition-grafting of UiO-66-NH2 and their application in oily water separations, Chemical Engineering Science, 260(2022) 117934. X. Zhu, Z. Yu, H. Zeng, X. Feng, Y. Liu, K. Cao, X. Li, R. Long, Using a simple method to prepare UiO‐66‐NH2/chitosan composite membranes for oil–water separation, Journal of Applied Polymer Science, 138(2021) 50765. T. Kameda, M. Tochinai, S. Kumagai, T. Yoshioka, Mg− Al layered double hydroxide intercalated with CO32–and its recyclability for treatment of SO2, Applied Clay Science, 183(2019) 105349. M. Everaert, K. Slenders, K. Dox, S. Smolders, D. De Vos, E. Smolders, The isotopic exchangeability of phosphate in Mg-Al layered double hydroxides, Journal of Colloid and Interface Science, 520(2018) 25-32. Z. Tahsiri, M. Niakousari, S. Hosseini, M. Majdinasab, Magnetic layered double hydroxide nanosheet as a biomolecular vessel for enzyme immobilization, International Journal of Biological Macromolecules, 209(2022) 1422-9. Y. Cao, A. Khan, T.A. Kurniawan, R. Soltani, A.B. Albadarin, Synthesis of hierarchical micro-mesoporous LDH/MOF nanocomposite with in situ growth of UiO-66-(NH2) 2 MOF on the functionalized NiCo-LDH ultrathin sheets and its application for thallium (I) removal, Journal of Molecular Liquids, 336(2021) 116189. M.A. Iqbal, M. Secchi, M.A. Iqbal, M. Montagna, C. Zanella, M. Fedel, MgAl-LDH/graphene protective film: Insight into LDH-graphene interaction, Surface and Coatings Technology, 401(2020) 126253. Z. Yang, S. Li, X. Xia, Y. Liu, Hexagonal MgAl-LDH simultaneously facilitated active facet exposure and holes storage over ZnIn2S4/MgAl-LDH heterojunction for boosting photocatalytic activities and anti-photocorrosion, Separation and Purification Technology, 300(2022) 121819. J. Long, Z. Yang, J. Huang, X. Zeng, Self-assembly of exfoliated layered double hydroxide and graphene nanosheets for electrochemical energy storage in zinc/nickel secondary batteries, Journal of Power Sources, 359(2017) 111-8. T. Lu, Y. Sun, M. Shi, D. Ding, Z. Ma, Y. Pan, Y. Yuan, W. Liao, Y. Sun, Ni dopped MgAl hydrotalcite catalyzed hydrothermal liquefaction of microalgae for low N, O bio-oil production, Fuel, 333(2023) 126437. X. Guo, P. Yin, H. Yang, Superb adsorption of organic dyes from aqueous solution on hierarchically porous composites constructed by ZnAl-LDH/Al (OH) 3 nanosheets, Microporous and Mesoporous Materials, 259(2018) 123-33. Z.P. Xu, G.Q. Lu, Hydrothermal synthesis of layered double hydroxides (LDHs) from mixed MgO and Al2O3: LDH formation mechanism, Chemistry of Materials, 17(2005) 1055-62. S. Dong, Y. Jia, X. Xu, J. Luo, J. Han, X. Sun, Crystallization and properties of poly (ethylene terephthalate)/layered double hydroxide nanocomposites, Journal of colloid and interface science, 539(2019) 54-64. H. Li, Y. Yin, L. Zhu, Y. Xiong, X. Li, T. Guo, W. Xing, Q. Xue, A hierarchical structured steel mesh decorated with metal organic framework/graphene oxide for high-efficient oil/water separation, Journal of hazardous materials, 373(2019) 725-32. Y. Liao, M. Tian, R. Wang, A high-performance and robust membrane with switchable super-wettability for oil/water separation under ultralow pressure, Journal of Membrane Science, 543(2017) 123-32. Q. Pan, M. Wang, H. Wang, Separating small amount of water and hydrophobic solvents by novel superhydrophobic copper meshes, Applied Surface Science, 254(2008) 6002-6. Z.-M. Zhang, Z.-Q. Gan, R.-Y. Bao, K. Ke, Z.-Y. Liu, M.-B. Yang, W. Yang, Green and robust superhydrophilic electrospun stereocomplex polylactide membranes: Multifunctional oil/water separation and self-cleaning, Journal of Membrane Science, 593(2020) 117420. J.J. Jiang JingXian, Z.Q. Zhang QingHua, Z.X. Zhan XiaoLi, C.F. Chen FengQiu, A multifunctional gelatin-based aerogel with superior pollutants adsorption, oil/water separation and photocatalytic properties, (2019). P.-B. Li, Y.-X. Wang, Z.-X. Shao, B.-T. Wu, H. Li, M.-M. Gao, K.-G. Liu, K.-R. Shi, Enhanced corrosion protection of magnesium alloy via in situ Mg–Al LDH coating modified by core–shell structured Zn–Al LDH@ ZIF-8, Rare Metals, 41(2022) 2745-58. Y. Yousefzadeh, V. Izadkhah, S. Sobhanardakani, B. Lorestani, S. Alavinia, UiO-66-NH2/guanidine-functionalized chitosan: a new bio-based reusable bifunctional adsorbent for removal of methylene blue from aqueous media, International Journal of Biological Macromolecules, 254(2024) 127391. D.L. Zhao, W.S. Yeung, Q. Zhao, T.-S. Chung, Thin-film nanocomposite membranes incorporated with UiO-66-NH2 nanoparticles for brackish water and seawater desalination, Journal of Membrane Science, 604(2020) 118039. W. Ma, N. Zhao, G. Yang, L. Tian, R. Wang, Removal of fluoride ions from aqueous solution by the calcination product of Mg–Al–Fe hydrotalcite-like compound, Desalination, 268(2011) 20-6. Y. Yang, N. Gao, W. Chu, Y. Zhang, Y. Ma, Adsorption of perchlorate from aqueous solution by the calcination product of Mg/(Al–Fe) hydrotalcite-like compounds, Journal of Hazardous Materials, 209(2012) 318-25. J.M. Fernández, M.A. Ulibarri, F.M. Labajos, V. Rives, The effect of iron on the crystalline phases formed upon thermal decomposition of Mg-Al-Fe hydrotalcites, Journal of Materials Chemistry, 8(1998) 2507-14. S.J. Garibay, S.M. Cohen, Isoreticular synthesis and modification of frameworks with the UiO-66 topology, Chemical communications, 46(2010) 7700-2. Y. Su, Z. Zhang, H. Liu, Y. Wang, Cd0. 2Zn0. 8S@ UiO-66-NH2 nanocomposites as efficient and stable visible-light-driven photocatalyst for H2 evolution and CO2 reduction, Applied Catalysis B: Environmental, 200(2017) 448-57. P. Chen, L. Chen, X.a. Dong, H. Wang, J. Li, Y. Zhou, C. Xue, Y. Zhang, F. Dong, Enhanced photocatalytic VOCs mineralization via special Ga-OH charge transfer channel in α-Ga2O3/MgAl-LDH heterojunction, ACS ES&T Engineering, 1(2020) 501-11. N. Wen, X. Miao, X. Yang, M. Long, W. Deng, Q. Zhou, W. Deng, An alternative fabrication of underoil superhydrophobic or underwater superoleophobic stainless steel meshes for oil-water separation: Originating from one-step vapor deposition of polydimethylsiloxane, Separation and Purification Technology, 204(2018) 116-26. G. Wang, Y. He, H. Wang, L. Zhang, Q. Yu, S. Peng, X. Wu, T. Ren, Z. Zeng, Q. Xue, A cellulose sponge with robust superhydrophilicity and under-water superoleophobicity for highly effective oil/water separation, Green Chemistry, 17(2015) 3093-9. D. Zhong, X. Wang, J. Wang, Green electrospun poly (vinyl alcohol)/silicon dioxide nanofibrous membrane coated with polydopamine in the presence of strong oxidant for effective separation of surfactant-stabilized oil-in-water emulsion, Surface and Coatings Technology, 460(2023) 129421. Scheme Scheme 1 is are available in the Supplementary Files section. Additional Declarations No competing interests reported. Supplementary Files SupportingInformation.docx MovieS1.mp4 MovieS3.mp4 Scheme1.docx Cite Share Download PDF Status: Published Journal Publication published 03 Dec, 2025 Read the published version in Cellulose → Version 1 posted Editorial decision: Revision requested 14 Jun, 2025 Editor assigned by journal 14 Jun, 2025 Submission checks completed at journal 06 Jun, 2025 First submitted to journal 04 Jun, 2025 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. 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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-6820860","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":471364814,"identity":"6296b255-f803-49a8-8b03-8acaa18d4a49","order_by":0,"name":"Hongmei Wang","email":"","orcid":"","institution":"Changsha University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Hongmei","middleName":"","lastName":"Wang","suffix":""},{"id":471364815,"identity":"49827870-7d6d-4139-9099-b4d2182be0bc","order_by":1,"name":"Jiawen Zhang","email":"","orcid":"","institution":"Changsha University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Jiawen","middleName":"","lastName":"Zhang","suffix":""},{"id":471364816,"identity":"a2f31106-a742-4541-94f9-e2fe74895fb2","order_by":2,"name":"Zhenggang Wang","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCUlEQVRIiWNgGAWjYDACCRSegY0cG3v7AVK0FKQZ8/GcSSBFy4dDifMkHAzw6pCf3Xzs4ZdfdnnyEcnPHn4xOJDeJsGQwPCjYhtOLYxzjqUby/YlFxveSDM3ljG4k9sm3XiAsefMbZxamCVyzKQle5gTN85OMJOWMHiW2yZzIIGZsQ23FjaJ/G9ALfVALenfgFoOp7NJJBjg1cIjkcMm+eHH4cT50jlmkh8MDicQ1CIhkWYmzdhwPHGD/JsyaQaDNMM2YCAfxOcX+RnJzyR//KlOnN9zfBuQYSMv395+8MGPCtxawEHA2waM9wNABg9U5ABe9UDA+OMP0LoGEIOQ0lEwCkbBKBiRAAB+GFsapFqsZgAAAABJRU5ErkJggg==","orcid":"","institution":"Changsha University of Science and Technology","correspondingAuthor":true,"prefix":"","firstName":"Zhenggang","middleName":"","lastName":"Wang","suffix":""},{"id":471364817,"identity":"16b8e882-6648-4704-9945-392ef1475dc4","order_by":3,"name":"Shuang Hu","email":"","orcid":"","institution":"Changsha University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Shuang","middleName":"","lastName":"Hu","suffix":""},{"id":471364818,"identity":"3407220d-2e63-42d1-9154-5f2556b9db62","order_by":4,"name":"Zhuang Fu","email":"","orcid":"","institution":"Changsha University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Zhuang","middleName":"","lastName":"Fu","suffix":""},{"id":471364819,"identity":"7cbad26b-8c29-49c9-9dda-b51b07816b76","order_by":5,"name":"Jingfeng Zhang","email":"","orcid":"","institution":"YiBin Grace Group Co., LTD","correspondingAuthor":false,"prefix":"","firstName":"Jingfeng","middleName":"","lastName":"Zhang","suffix":""},{"id":471364820,"identity":"3d9fdd70-3913-4786-bdc5-ae1a1da02ac8","order_by":6,"name":"Xichao Liang","email":"","orcid":"","institution":"YiBin Grace Group Co., LTD","correspondingAuthor":false,"prefix":"","firstName":"Xichao","middleName":"","lastName":"Liang","suffix":""}],"badges":[],"createdAt":"2025-06-04 13:09:00","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6820860/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6820860/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1007/s10570-025-06875-3","type":"published","date":"2025-12-03T15:58:15+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":85755665,"identity":"5a291b8d-8e28-4978-86f0-ce0d5e7a337e","added_by":"auto","created_at":"2025-07-01 10:45:21","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":442212,"visible":true,"origin":"","legend":"\u003cp\u003eFE-SEM micrographs of pure SA membrane (a), the composite membranes U-LDH\u003csub\u003e1\u003c/sub\u003e@SA (b), U-LDH\u003csub\u003e3\u003c/sub\u003e@SA (c) and U-LDH\u003csub\u003e5\u003c/sub\u003e@SA (d), SEM-EDS element mapping analysis of the composite membranes U-LDH\u003csub\u003e3\u003c/sub\u003e@SA (e).\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/2d67582d7f30c572e4176838.png"},{"id":85754029,"identity":"b26c4c8e-160f-4163-a1ac-ecf09e673e45","added_by":"auto","created_at":"2025-07-01 10:37:21","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":75635,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR (a) and XRD (b) patterns of MgAl-LDHs, UiO-66-NH\u003csub\u003e2 \u003c/sub\u003eand U-LDH\u003csub\u003e3\u003c/sub\u003e. TGA (c) patterns of the pure SA membrane and the composite membranes U-LDH\u003csub\u003e1\u003c/sub\u003e@SA, U-LDH\u003csub\u003e3\u003c/sub\u003e@SA and U-LDH\u003csub\u003e5\u003c/sub\u003e@SA.\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/69a71525f473d2e382a5a05d.png"},{"id":85755657,"identity":"a47cb9fb-67c4-4c54-a712-e8df9137eae0","added_by":"auto","created_at":"2025-07-01 10:45:21","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":131531,"visible":true,"origin":"","legend":"\u003cp\u003eFull spectrum of the composite membranes U-LDH\u003csub\u003e3@\u003c/sub\u003eSA (a); C 1s, O 1s, N 1s, Zr 3d and Al 2p spectra of the composite membranes U-LDH\u003csub\u003e3\u003c/sub\u003e@SA (b-f).\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/c07611c7ee27626d6f7cd758.png"},{"id":85754033,"identity":"18de3fca-44d1-4372-98dc-378834be5493","added_by":"auto","created_at":"2025-07-01 10:37:21","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":185535,"visible":true,"origin":"","legend":"\u003cp\u003eWCA (a) of pure SA membranes and U-LDH\u003csub\u003e3\u003c/sub\u003e@SA composite membranes in air. Underwater OCAs (b) of U-LDHn@SA composite membranes. AFM images (c) of pure SA, U-LDH\u003csub\u003e1\u003c/sub\u003e@SA, U-LDH\u003csub\u003e3\u003c/sub\u003e@SA and U-LDH\u003csub\u003e5\u003c/sub\u003e@SA membrane. Oil repellent and hydrophilicity mechanism diagrams of U-LDHn@SA membranes (d).\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/5dd3485ee35be2f13d393a2e.png"},{"id":85754034,"identity":"0c61d170-b95a-418d-86ed-4aeff7c19d6d","added_by":"auto","created_at":"2025-07-01 10:37:21","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":186097,"visible":true,"origin":"","legend":"\u003cp\u003eThe o/w separation tests (a); Water permeation flux and efficiencies of the U-LDHn@SA composite membrane (b). The o/w separation flux and efficiency of the U-LDH\u003csub\u003e3\u003c/sub\u003e@SA composite using different oils (c).\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/4f62eda4e0678b34cd98ffa9.png"},{"id":85755695,"identity":"04e8bc59-1d49-4719-9fc0-e1805965cb26","added_by":"auto","created_at":"2025-07-01 10:45:21","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":200792,"visible":true,"origin":"","legend":"\u003cp\u003eThe permeation flux and separation efficiency of U-LDH\u003csub\u003e3\u003c/sub\u003e@SA composite membrane after 10 cycles (a); Separation efficiency for mixtures of transformer oils and different pH water (pH=1 and 12.0) and 0.1 M NaCl solution (b and c). Photographs of the antifouling capability of the membrane (d).\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/9ea0056b422267507579a5dd.png"},{"id":85754037,"identity":"812ddd95-8985-45ad-b154-3cbac17cbac7","added_by":"auto","created_at":"2025-07-01 10:37:21","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":231709,"visible":true,"origin":"","legend":"\u003cp\u003eThe oil rejection abilities of the composite membrane for different o/w emulsions (a). Photographs, optical microscopic images (b), and DLS graphs (c) of the feed and filtrate, respectively (Synthetic ester oil as an example).Schematic illustration of separation behaviors for oil/water emulsions (d).\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/02252235dce0c446f2b234b3.png"},{"id":97724159,"identity":"27c462d1-8af4-481c-a693-e921a1601544","added_by":"auto","created_at":"2025-12-08 16:12:11","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2105736,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/194cbc7d-b85d-4680-8c90-798ab7f0f514.pdf"},{"id":85756940,"identity":"e1ba822d-ad81-4d0a-a5ac-8b16cb7b907d","added_by":"auto","created_at":"2025-07-01 10:53:21","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":1329548,"visible":true,"origin":"","legend":"","description":"","filename":"SupportingInformation.docx","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/39f830764890d8ef1d700169.docx"},{"id":85754039,"identity":"e2beb6da-aa57-43f8-b601-6de5142042fe","added_by":"auto","created_at":"2025-07-01 10:37:22","extension":"mp4","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":5728981,"visible":true,"origin":"","legend":"","description":"","filename":"MovieS1.mp4","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/2ec7b7e71a6b6225c1682c1a.mp4"},{"id":85754040,"identity":"36ed6816-bc57-4ed8-bec2-4661d8390fdd","added_by":"auto","created_at":"2025-07-01 10:37:22","extension":"mp4","order_by":4,"title":"","display":"","copyAsset":false,"role":"supplement","size":6368822,"visible":true,"origin":"","legend":"","description":"","filename":"MovieS3.mp4","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/c6b17ad3a2c825f99304dfb3.mp4"},{"id":85754038,"identity":"18737624-4e87-4cde-b6a8-5f87290b1c0e","added_by":"auto","created_at":"2025-07-01 10:37:22","extension":"docx","order_by":5,"title":"","display":"","copyAsset":false,"role":"supplement","size":5664589,"visible":true,"origin":"","legend":"","description":"","filename":"Scheme1.docx","url":"https://assets-eu.researchsquare.com/files/rs-6820860/v1/138b05beb2bb30bc50315275.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Preparation of UiO-66-NH 2 /MgAl-LDHs @ Sodium Alginate Fiber Membrane and Determination of Oil Water Separation Performance","fulltext":[{"header":"Introduction","content":"\u003cp\u003eOil spills and waste oil discharges produce large quantities of oily wastewater, which not only causes serious ecological and environmental problems but also threatens human health (Li, et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Liu, et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Xie, et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Consequently, there is a pressing need to develop effective measures to address the issues related to oily wastewater. There are many o/w separation technologies such as coagulation, flotation, membrane separation, absorption, and centrifugation (Huang, et al. \u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; (Wu, et al. \u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Xie, et al. \u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Zheng, et al. \u003cspan citationid=\"CR48\" class=\"CitationRef\"\u003e2020\u003c/span\u003e). Among these methods, membrane separation technology offers a number of advantages, including simple operation, low cost, and the absence of secondary pollution (Yang, et al. \u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). These attributes make it an attractive option for the treatment of oily wastewater. Thus, there has been an increased focus on the study of superhydrophilic underwater superoleophobic (SUS) membranes (Yue, et al. \u003cspan citationid=\"CR43\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Zhang, et al. \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e2014\u003c/span\u003e). Biomass materials, such as cellulose, chitosan, and wood, have garnered significant attention due to their distinctive spatial structure and the presence of numerous active functional groups (Zhang, et al. \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). Sodium alginate (SA) is a pervasive marine biopolymer derived from the cellular structure of various brown algae (Liu, et al. \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Due to the presence of its oxygen-containing functional groups (-COOH, -OH, etc.), sodium alginate has been utilized as a hydrophilic membrane matrix (Ehsan, et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2023\u003c/span\u003e). In the realm of membrane technologies for oil-water separation, an efficacious strategy to bolster both the flux and overall performance involves the strategic integration of hydrophilic particles within the membrane matrix. This approach serves a dual function: it not only regulates the pore size of the membrane but also changes the surface morphology to increase the roughness, which significantly increases the hydrophilicity of the membrane surface (Wahid, et al. \u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e2021\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eMOFs are characterized by their high porosity, large specific surface area, and adjustable pore size, as well as their clear molecular adsorption sites (Awwad, et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2023\u003c/span\u003e; Elrasheedy, et al. \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Yu, et al. \u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). These properties have led to the use of MOF in a variety of applications, including gas separation (Daglar, et al. 2020), energy conversion (Wang, et al. \u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e2018\u003c/span\u003e), and metal ion adsorption (Ihsanullah. 2022). Notably, UiO-66-NH\u003csub\u003e2\u003c/sub\u003e has emerged as a particularly promising material, exhibiting remarkable heat resistance, high water stability, and substantial adsorption capacity (Shen, et al. \u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). Consequently, the utilization of UiO-66-NH\u003csub\u003e2\u003c/sub\u003e has been extended to the surface modification of oil-water separation membranes. And the functional group (-NH\u003csub\u003e2\u003c/sub\u003e) in UiO-66-NH\u003csub\u003e2\u003c/sub\u003e can be utilized to introduce hydrophilic modifications to the membrane (Zhu, et al. \u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Layered double hydroxides are classified as anionic layered compounds. LDH possesses a distinctive structural configuration, characterized by an abundance of hydroxyl groups situated between the layers and on the material's surface. The layered double hydroxide (LDH) material possesses a number of advantageous properties, including a substantial specific surface area, adequate porosity, and a stable layer structure (Everaert, et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Kameda, et al. \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Tahsiri, et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). The MgAl-LDH nanosheets exhibit a micrometer-sized morphology, yet possess a thickness measured in nanometers (Cao, et al. \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Iqbal, et al. \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e2020\u003c/span\u003e; Yang, et al. \u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e2022\u003c/span\u003e). This structural characteristic is particularly conducive to the loading of nanoscale UiO-66-NH\u003csub\u003e2\u003c/sub\u003e onto the LDH nanosheets, thereby augmenting the overall dimensions of the particles, and further increase the hydrophilicity of the membrane surface at the same time (Guo, et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2018\u003c/span\u003e; Long, et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2017\u003c/span\u003e; Lu, et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2023\u003c/span\u003e).\u003c/p\u003e \u003cp\u003eIn light of the aforementioned findings, sodium alginate fiber was selected as the substrate for the construction of superhydrophilic films aimed at facilitating oil-water separation in this study. The pore structure of the hydrophilic membrane was modified through the incorporation of UiO-66-NH\u003csub\u003e2\u003c/sub\u003e/MgAl-LDH cluster-assembled microsphere, aiming to elucidate its correlation with the oil-water separation efficacy of the film. The morphology of the membrane was characterized by XPS, SEM, and AFM etc. And the separation performance was characterized by separation flux, separation efficiency, and oil cut-off rate. This research will provide an approach for designing multifunctional membranes for o/w separation.\u003c/p\u003e"},{"header":"Experimental","content":"\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.1 Materials\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe sodium alginate raw material for the preparation of sodium alginate fiber was obtained from Yantai Hongri Biotechnology Co. Dopamine hydrochloride (C\u003csub\u003e8\u003c/sub\u003eH\u003csub\u003e11\u003c/sub\u003eNO\u003csub\u003e2\u003c/sub\u003e\u0026middot;HCl), zirconium chloride (ZrCl\u003csub\u003e4\u003c/sub\u003e), 2-aminoterephthalic acid (C\u003csub\u003e8\u003c/sub\u003eH\u003csub\u003e7\u003c/sub\u003eNO\u003csub\u003e4\u003c/sub\u003e), magnesium nitrate hexahydrate (Mg(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e\u0026middot;6H\u003csub\u003e2\u003c/sub\u003eO), aluminum nitrate hydrate (Al(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e3\u003c/sub\u003e\u0026middot;9H\u003csub\u003e2\u003c/sub\u003eO), urea (CH\u003csub\u003e4\u003c/sub\u003eN\u003csub\u003e2\u003c/sub\u003eO), Sudan\u0026nbsp;Ⅲ\u0026nbsp;were obtained from Shanghai Macklin Biochemical Technology Co. Ltd, concentrated ammonia, N,N-dimethylformamide (DMF), methanol were of analytical grade.\u003c/p\u003e\n\u003ch2\u003e2.2 Preparation of sodium alginate fibre\u003c/h2\u003e\n\u003cp\u003e955 g of deionised water was added to 45 g of sodium alginate raw material weighed in advance, which was then stirred at 80 \u0026deg;C for 1 h to obtain 1000 g of sodium alginate solution with a concentration of 4.5%. The solution was defoamed by centrifugation at 10000 rpm for 10 mi\u003cu\u003en\u003c/u\u003e at 50 ℃ to obtain the sodium alginate solution for spinning, which was loaded into a stainless steel storage tank with an insulated jacket (the temperature of the jacketed insulated water was 50 ℃). The sodium alginate solution was pressurised with compressed air through a spinneret nozzle with a diameter of 0.05 mm \u0026times; 800 holes into a coagulation bath consisting of a 5 wt% aqueous solution of calcium chloride at a bath temperature of 25 ℃. The regenerated fibres were subjected to a series of processes, including drawing, washing and oiling, to obtain sodium alginate fibres in a wet state. Subsequently, the wet fibre was placed in a refrigerator at -80 ℃ for 4 h, after which the frozen wet fibre was freeze-dried to obtain the final sodium alginate fibre.\u003c/p\u003e\n\u003ch2\u003e2.3 Preparation of U-LDHn cluster-assembled microsphere\u003c/h2\u003e\n\u003cp\u003eMgAl-LDHs were prepared through a solvothermal method. Typically, 0.02 mol of Mg(NO\u003csub\u003e3\u003c/sub\u003e)\u003csub\u003e2\u003c/sub\u003e\u0026middot;6H\u003csub\u003e2\u003c/sub\u003eO and 0.01 mol of Al(NO\u003csub\u003e3\u003c/sub\u003e)\u0026middot;9H\u003csub\u003e2\u003c/sub\u003eO were added to 100 mL of deionised water. Then, 6 g of urea were added into the solution under continuous stirring for 5 min. The mixed solution was transferred to a 100 mL stainless steel hot press kettle and stored for 24 h at 110 ℃(Xu, et al. 2005; Dong, et al. 2019). The solid product obtained was collected by centrifugation and washed three times with deionised water to remove excess reactants. The sample obtained was baked in a vacuum drying oven at 60 ℃ for 12 h.\u003c/p\u003e\n\u003cp\u003eDifferent weight (0.05 g, 0.15 g, 0.25 g, 0.35 g, 0.45 g) of MgAl-LDHs were added to 50 mL of DMF, which were stirred for 30 min, respectively. Then, 0.2332 g of ZrCl\u003csub\u003e4\u0026nbsp;\u003c/sub\u003eand 0.1812 g of H\u003csub\u003e2\u003c/sub\u003eBDC-NH\u003csub\u003e2\u003c/sub\u003e were added to the above solutions, which were stirred for 1 h to allow for full dissolution.\u0026nbsp;The mixed solution was transferred to a 100 mL stainless steel autoclave and stored at 120 ℃ for 48 h(Li, et al. 2019). The solid product was collected by centrifugation and washed 6 times with methanol to remove excess reactants. The resulting sample was baked in a vacuum oven at 80 ℃ for 12 h. The obtained scluster-assembled microsphere was coded as U-LDH\u003csub\u003e1\u003c/sub\u003e, U-LDH\u003csub\u003e2\u003c/sub\u003e,\u003csub\u003e\u0026nbsp;\u003c/sub\u003eU-LDH\u003csub\u003e3\u003c/sub\u003e,\u003csub\u003e\u0026nbsp;\u003c/sub\u003eU-LDH\u003csub\u003e4\u0026nbsp;\u003c/sub\u003eand U-LDH\u003csub\u003e5\u003c/sub\u003e,\u0026nbsp;which different content of MgAl-LDHs were 12.5%, 30.0%, 41.7%, 50.0%, and 56.3%, respectively.\u003c/p\u003e\n\u003ch2\u003e2.4 Fabrication of superhydrophilic membrane\u003c/h2\u003e\n\u003cp\u003eSodium alginate was crushed to powder using a crusher, then 0.5 g of the scluster-assembled sphere U-LDHn and 0.6 g of sodium alginate fibres were weighed and dispersed in deionised water to give 45 g of suspension. Dilute ammonia was added to the above suspension to adjust the pH of the suspension to 8.5. After sonication for 30 min, 0.7 g of dopamine hydrochloride was weighed and dissolved in 15 mL of deionised water and the dopamine hydrochloride solution was added to the above suspension which was stirred at 30 ℃ for 24 h(Liao, et al. 2017). Finally, 15 g of the suspension was weighed and then vacuum filtration onto cellulose acetate filter paper (the effective area of the cellulose acetate filter paper was 2.54 cm\u003csup\u003e-2\u003c/sup\u003e), and then dried under vacuum at 45 ℃ for 4 h.\u003c/p\u003e\n\u003ch2\u003e2.5 Characterization\u003c/h2\u003e\n\u003cp\u003eA Fourier transform infrared spectrometer (FTIR) (Avatar-360, USA) was used to study the chemical structure of the synthesized particles and membranes. The wave number range of all spectra was 4000 cm\u003csup\u003e-1\u003c/sup\u003e to 400 cm\u003csup\u003e-1\u003c/sup\u003e.XRD analyses were performed using a D8 ADVANCE Ultra Front Diffractometer with a scan rate of 4\u0026deg; min\u003csup\u003e-1\u003c/sup\u003e in the 2\u0026theta; range of 5~80\u0026deg;. Microscopic analyses of the samples were performed using a ZEISS-Gemini SEM 500 (Germany), and all samples were sprayed with gold prior to microscopic observation. Atomic force micro-scopy (AFM, Bruker) was applied to investigate the surface roughness from a membrane area of 15 \u0026mu;m\u0026nbsp;\u0026times;\u0026nbsp;15\u0026nbsp;\u0026mu;m\u0026nbsp;in tapping mode. The surface composition of the membranes was studied by X-ray photoelectron spectroscopy (XPS, AXIS SUPRA+). Thermogravimetric analysis of the composite membranes was carried out using an NETZSCH/STA449F5 thermogravimetric analyzer. The samples were placed in a TGA sample cup and heated from room temperature to 800\u0026nbsp;℃\u0026nbsp;at a heating rate of 10\u0026nbsp;℃\u0026nbsp;min\u003csup\u003e-1\u003c/sup\u003e. Surface properties such as surface area, pore volume and pore diameter were measured using a Bruauer - Emmet - Teller (BET) analyser (JW-BK100). The surface wettability of the membranes was investigated using a SDC-80 contact angle meter.\u0026nbsp;\u003c/p\u003e\n\u003ch2\u003e2.6 Oil/water separation\u003c/h2\u003e\n\u003cp\u003eThe U-LDHn@SA membrane was wetted by water, then the wetted membrane was sandwiched between two Teflon flanges. The oil/water mixture can be prepared by mixing synthetic ester oil, transformer oil, dichloromethane into water (20 mL, V\u003csub\u003eoil\u003c/sub\u003e/V\u003csub\u003ewater\u003c/sub\u003e =1/1), and then slowly pouring it into the separation apparatus. The separation efficiency (\u003cem\u003e\u0026eta;\u003c/em\u003e) is calculated by the following equation(Pan, et al. 2008)：\u003c/p\u003e\n\u003cp\u003e\u003cimg 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\"\u003e\u003c/p\u003e\n\u003cp\u003ewhere \u003cem\u003eJ\u003c/em\u003e represents flux (L m\u003csup\u003e-2\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e), \u003cem\u003eV\u003c/em\u003e represents the filtrate volume (L), \u003cem\u003eS\u003c/em\u003e represents the effective area (m\u003csup\u003e2\u003c/sup\u003e),\u0026nbsp;\u003cem\u003e∆\u003c/em\u003e\u003cem\u003et\u003c/em\u003e represents the separating time (h).\u003c/p\u003e\n\u003cp\u003eFor emulsion separation, 10 mL of oil was mixed with 490 mL water, followed by the addition of Tween-80 (0.05 g) and sonicated for 3 h to obtain a stable oil-in-water emulsion. The prepared emulsion was added into the upper receiver of the filtration equipment and negative pressure of \u0026lt;0.1 bar was applied to separate the emulsion. The con\u0026shy;centration of the oil in pure emulsion and filtrates was measured by a UV\u0026ndash;vis spectrometer (\u0026lambda; = 340 ~ 600) and the oil rejection percentage was calculated by the Eq(Jiang JingXian, et al. 2019):\u003c/p\u003e\n\u003cp\u003e\u003cimg src=\"data:image/png;base64,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\"\u003e\u003c/p\u003e\n\u003cp\u003eWhere \u003cem\u003eC\u003csub\u003e0\u003c/sub\u003e\u003c/em\u003e and \u003cem\u003eC\u003csub\u003ef\u003c/sub\u003e\u003c/em\u003e are the concentrations of oil in the pure emulsion and filtrates, respectively.\u003c/p\u003e\n\u003ch2\u003e2.7 Reusability and stability\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003eThe wettability of the membrane was determined by measuring the contact angle of water and oil on the membrane at room temperature. The water contact angles (WCA) of samples were measured with an SDC-80 static contact angle analyzer at 25 \u0026deg;C. The same method was used to determine the oil contact angle (OCA) underwater. The adhesion of the oil is observed by repeatedly contacting the membrane surface with the oil droplets.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cem\u003e2.8 Data analysis\u003c/em\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAt least three repeat times were set up during the test and the data were presented as \u0026quot;mean \u0026plusmn; standard deviation\u0026quot; (n = 3).\u003c/p\u003e"},{"header":"Results and discussion","content":"\u003ch2\u003e3.1 Characterization of U-LDHn @ SA composite Membrane\u0026nbsp;\u003c/h2\u003e\n\u003cp\u003e\u0026nbsp;The surface morphologies of the pure SA membrane, and the composite membranes U-LDHn@SA are shown in Fig. 1. As illustrated in Fig. 1a, the pure SA membrane exhibits a homogeneous surface morphology, primarily composed of aggregated sodium alginate fibers. These fibers are densely packed, forming a compact membrane structure that will impede water permeation. The dense architecture of the SA membrane is likely attributed to the formation of intermolecular hydrogen bonds between closely aligned fibers, which undergo irreversible structural changes upon drying. As shown in Fig.1c\u003csub\u003e2\u003c/sub\u003e, the synthesized pure MgAl-LDHs are smooth hexagonal sheet structures and the size of individual MgAl-LDHs nanosheets can reach up to 2 \u0026mu;m, with a thickness of only nanoscale, which makes it easy to attach UiO-66-NH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003enanoparticles (Fig. S1 and S2). The morphology of pure UiO-66-NH\u003csub\u003e2\u003c/sub\u003e is more regular spheres, and its particle sizes range from 50 to 200 nm(Zhu, et al. 2021). As shown in Fig. 1c\u003csub\u003e1\u003c/sub\u003e, UiO-66-NH\u003csub\u003e2\u003c/sub\u003e was successfully loaded onto MgAl-LDHs and the two were clustered together, resulting in the overall size of the U-LDHn clustered microspheres being increased from the nanometer scale to the micrometer scale. The micrometer-sized U-LDHn cluster-assembled microspheres were further embedded within SA nanofibers, resulting in a roughened surface morphology of the U-LDHn@SA composite membrane. This unique encapsulation method can induce the formation of loosely stacked nanofiber structures, which can improve water permeability. Increasing the amount of MgAl-LDHs increases the hexagonal lamellar structure in the clustered U-LDHn as shown in Fig. 1b and 1d. EDS has been used to characterize elemental distribution on the surface of the composite Membrane U-LDH\u003csub\u003e3\u003c/sub\u003e@SA, respectively. As illustrated in Fig. 1e, the EDS has been mapped from Fig. 1c\u003csub\u003e1\u003c/sub\u003e,\u003csub\u003e\u0026nbsp;\u003c/sub\u003edemonstrated the present of Mg, Al, and Zr elements, and are uniformly distributed on the membrane surface.\u003c/p\u003e\n\u003cp\u003e\u0026nbsp;The FTIR spectra of MgAl-LDHs, UiO-66-NH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eand U-LDHn are shown in Fig.2a. The main characteristic peaks of U-LDHn were almost identical to those of pure UiO-66-NH\u003csub\u003e2\u003c/sub\u003e. The peaks located at 3462 and 3355 cm\u003csup\u003e-1\u003c/sup\u003e are asymmetric and symmetric stretching vibrations of the -NH\u003csub\u003e2\u003c/sub\u003e group, and the signal at 1585 cm\u003csup\u003e-1\u003c/sup\u003e is due to -COOH and Zr\u003csup\u003e4+\u003c/sup\u003e coordination(Li, et al. 2022).\u0026nbsp;These results indicated that the successful introducing of UiO-66-NH\u003csub\u003e2\u0026nbsp;\u003c/sub\u003eto U-LDHn. The characteristic peak at 771 cm\u003csup\u003e-1\u003c/sup\u003e can be attributed to Al-OH vibrations, which suggest the presence of MgAl-LDHs in the composites(Yousefzadeh, et al. 2024). XRD analysis of UiO-66-NH\u003csub\u003e2\u003c/sub\u003e, MgAl-LDHs,\u0026nbsp;U-LDHn were also conducted to investigate the synthesis of U-LDHn. As illustrated in Fig.2b, the XRD spectra of U-LDHn exhibit distinctive diffraction peaks of UiO-66-NH\u003csub\u003e2\u003c/sub\u003e at 7.1\u0026deg;,\u0026nbsp;8.1\u0026deg;\u0026nbsp;which correspond to the (111), (002) crystal planes, respectively(Zhao, et al. 2020). The presence of MgAl-LDHs was observed as relatively weak signals on the XRD patterns of U-LDHs, with the most prominent peak occurring at 12.21\u0026deg;(Ma, et al. 2011). This phenomenon can be attributed to the particles of UiO-66-NH\u003csub\u003e2\u003c/sub\u003e covering the MgAl-LDHs, thereby obscuring the signal (Fig. S3). In summary, the results of IR and XRD spectroscopy indicate that the synthesis of U-LDHn was successful.\u003c/p\u003e\n\u003cp\u003eThe thermal characteristics of pure SA membranes and U-LDHn@SA composite membranes were evaluated using thermogravimetric analysis. As shown in Fig. 2c, three phases of weight loss were observed for the samples, the weight loss in the first phase (40-240 ℃) was mainly caused by the evaporation of adsorbed water on the surface of the samples. The detachment of the hydroxyl-containing groups of the material and the decomposition of the carbonate ions of LDH lead to the weight loss in the second stage (240-380 ℃)(Yang, et al. 2012; Fern\u0026aacute;ndez, et al. 1998). At temperatures above 380\u0026nbsp;℃, the hydrophilic ligand 2-aminoterephthalic acid, a component of UiO-66-NH\u003csub\u003e2\u003c/sub\u003e, also begins to decompose(Garibay, et al. 2010). When the temperature reached 800\u0026nbsp;℃, the total weight loss was 54% for pure SA and 47% for the composite membrane U-LDH\u003csub\u003e1\u003c/sub\u003e@SA. By further increasing the ratio of MgAl-LDH instead, the thermal stability of the membrane was weakened. The total weight loss of the composite membrane U-LDH\u003csub\u003e5\u003c/sub\u003e@SA reaches 60%, indicating that the higher content of hydrophilic groups in the composite material improves the hydrophilicity of the material.\u003c/p\u003e\n\u003cp\u003eIn order to analyze the chemical structure of the membrane surface, XPS analysis of the composite membrane was carried out (Fig. 3). The full-spectrum scan illustrated the presence of C, O, N, Mg, Al, and Zr, which was consistent with the EDS results. The peaks at 401.8 eV and 399.9 eV in the N 1s pattern correspond to C\u0026minus;N and N\u0026minus;H. Within the context of the Zr 3d pattern, the spectral peaks manifested at binding energies of 182.4 eV and 184.9 eV can be ascribed to the Zr 3d 5/2 orbitals(Su, et al. 2017). In the Al 2p spectrum, the characteristic peak centered at 75.3 eV is attributed to the Al\u0026minus;O chemical bonding. Combining the above characterizations that MgAl-LDHs with UiO-66-NH\u003csub\u003e2\u003c/sub\u003e were successfully prepared and loaded onto sodium alginate fibers(Chen, et al. 2020). In the C 1s spectrum, the signals at 284.8 eV, 286.6 eV, and 288.4 eV correspond to C\u0026minus;C, C\u0026minus;O\u0026minus;C, and O\u0026minus;C=O bonds, respectively, which may be related to the structure of sodium alginate as well as to the formation of PDAs by self-polymerization of dopamine HCl.\u003c/p\u003e\n\u003ch2\u003e3.2 Surface wettability\u003c/h2\u003e\n\u003cp\u003eSurface wettability is a pivotal factor in assessing the oil-water separation efficiency of membranes, given its potential impact on the permeation flux and antifouling properties of the membrane. Thus, the contact angle was measured in both air and underwater environments. In the air, the drop of water immediately was spread on the SA membrane surface and forming an angle of 45.3\u0026ordm; (Fig. 4a). This observation indicates that the SA membrane is hydrophilic, this may attributable to the abundance of hydroxyl-containing groups on the surface of membrane. When the water droplet contacted the U-LDH\u003csub\u003e3\u003c/sub\u003e@SA composite membrane, it spread rapidly, resulting in a contact angle of zero degrees (Fig. 4a and Movie S1). The results demonstrated that the U-LDH\u003csub\u003e3\u003c/sub\u003e-modified, the U-LDHn@SA composite membrane exhibits superhydrophilic properties, facilitated to the application of oil-water separation. Subsequently, the underwater OCA of U-LDHn@SA composite membranes was evaluated by fire-resistant oil. The underwater OCA were all around 140\u0026ordm;\u0026nbsp;for U-LDHn@SA composite membranes (Fig. 4b). To further investigate the self-cleaning and anti-fouling performance of the U-LDHn@SA composite membrane, a dynamic oil wetting test was performed on the membrane. As depicted in Movie S2, an oil droplet (fire-resistant oil) contacted and then left the surface of the membrane in an aqueous environment. After complete contact with the U-LDHn@SA membrane surface, when the droplet upward lift, no discernible deformation was observed upon its departure from the membrane surface. These observations suggest that the composite membrane possesses underwater superoleophobic properties.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eNotably, as illustrated in Fig. 4c and 4d, the Ra values of the pure SA film and the U-LDHn@SA composite film were 49.3 and 89.3, respectively. The Ra of the composite membrane after the incorporation of U-LDHn cluster spheres exceeds twice that of the pure SA membrane. The surface wettability of a membrane increases with the roughness of the surface. Therefore, PDA and U-LDHn cluster-assembled microspheres improve the porosity and hydrophilicity of the membrane(Wen, et al. 2018).\u003c/p\u003e\n\u003ch2\u003e3.3 Oil/water separation\u003c/h2\u003e\n\u003cp\u003eThe separation performance of the composite membrane with an effective area of 2.54 cm\u003csup\u003e2\u003c/sup\u003e was investigated by using o/w mixture (transformer oil/water). The membrane was wetted in water for 2 min and fixed with a clip between two glass tubes (Fig. 5a). The oil and water mixture were added into the upper tube of the filtration device. As depicted in Fig. 5a, the U-LDHn@SA membrane exhibited a rapid permeation of the water and collected in a flask while the oil could not pass through the superhydrophilic membrane and was collected from the upper part of the tube. In contrast, when pure SA membrane was used, a single droplet of water could not pass through the membrane even a high negative pressure of 1.0 bar was applied for 3 min. The impermeability of the SA membrane may be due to the tight fiber arrangement, smooth surface, and small pore size (Fig. S4). As shown in Fig. 5b, the permeate flux of U-LDH\u003csub\u003e1\u003c/sub\u003e@SA membrane was 832.4 L m\u003csup\u003e-2\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e with high separation efficiency above 98%. The separation flux U-LDH\u003csub\u003e\u0026nbsp;\u003c/sub\u003e@SA membrane increased to 2661 L m\u003csup\u003e-2\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e with the MgAl-LDH content increased from 12.5% to 41.7%. However, the separation flux decreased significantly to 809.7 L m\u003csup\u003e-2\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e when MgAl-LDHs increased to 56.3%. These may because when the MgAl-LDH content is extremely low, the main constituents within the hydrophilic particle are small-sized UiO-66-NH\u003csub\u003e2\u003c/sub\u003e. The pores in the composite membrane were covered by an excess of small-sized UiO-66-NH\u003csub\u003e2\u003c/sub\u003e, which results in a reduction of the overall porosity of the membrane. When the MgAl-LDH content increased to 41.7%, the overall particle size of the U-LDHn cluster-assembled microsphere increased, which further led to a loosening of the fiber arrangement within the membrane, which increased the composite membrane\u0026apos;s porosity, thus increased the separation flux. However, as the MgAl-LDH content increased to 56.3%, the excessive MgAl-LDH micrometer-scale laminae obscured the pore space that the U-LDHn cluster-assembled microsphere made the membrane appear, leading to a decrease in the separation flux. In addition, several other o/w mixtures containing different oils such as synthetic ester oils, transformer oils, and methylenechloride were tested for separation using the U-LDH\u003csub\u003e3\u003c/sub\u003e@SA composite membrane. It has been demonstrated that composite membranes consistently demonstrate high separation fluxes for low relative molecular mass oils (synthetic ester oils and transformer oils) of around 2565 L m\u003csup\u003e-2\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e and relative low separation fluxes for high molecular mass oils (dichloromethane) of around 1988 L m\u003csup\u003e-2\u0026nbsp;\u003c/sup\u003eh\u003csup\u003e-1\u003c/sup\u003e.\u003c/p\u003e\n\u003ch2\u003e3.4 Recyclability, stability, and antifouling properties of the membrane\u003c/h2\u003e\n\u003cp\u003eIn order to examine the recyclability of the membrane, the U-LDH\u003csub\u003e3\u003c/sub\u003e@SA membrane were also subjected to cyclic separation tests. As depicted in Fig. 6a, the membrane exhibited separation of o/w mixture after 10 cycles. The separation flux decreased as the number of cycles increased, it may be because the membrane surface or pores absorbed much oil. Nonetheless, the separation efficiency of the membrane was essentially stabilized at 99%, and the separation flux was stabilized at approximately 2021 L m\u003csup\u003e-2\u0026nbsp;\u003c/sup\u003eh\u003csup\u003e-1\u003c/sup\u003e. The above results proved that U-LDH\u003csub\u003e3\u003c/sub\u003e@SA membrane has superior antifouling ability and excellent reusability. To evaluate the chemical stability of the U-LDH\u003csub\u003e3\u003c/sub\u003e@SA composite membrane, the transformer oil was separated from different pH water (pH = 1.0 and 12.0) and 0.1 M NaCl solution (Fig. 6b). As shown in Fig. 6c,\u0026nbsp;at pH = 12 a brown colored solution was collected in the receiving flask. It is possible that trace amounts of PDA molecules were eliminated during the washout process. The acid and salt solutions had no significant effect on the morphology of the composite membranes. Thus, the U-LDHn@SA membrane can be used to treat oily wastewater under weak acid, weak/medium alkaline, and saline conditions. To verify the anti-fouling and self-cleaning capability of the U-LDH\u003csub\u003e3\u003c/sub\u003e@SA membrane, underwater anti-fouling tests were conducted. As shown in Fig. 6d and Movie S3 the membrane was immersed in the water and tried to foul with the flow of oil, the oil rapidly slid off despite hitting the membrane with a high flow rate. Moreover, when the membrane was tried to immerse in the water/fire-resistant oil mixture, it was found to float on the oil-water interface and was clear after soaking in the oil. This entire experiment showed that the membrane possessed strong antifouling and self-cleaning ability, which could be a promising material for o/w separation.\u003c/p\u003e\n\u003ch2\u003e3.5 Oil-in-water emulsion separation\u003c/h2\u003e\n\u003cp\u003eIn comparison with o/w mixtures, o/w emulsions are challenging to treat due to their good stability and micro dimensions(Wang, et al. 2015). In this work, several o/w emulsions (transformer oil, synthetic ester oil and fire-resistant oil) were prepared and the separation performance of U-LDH\u003csub\u003e3\u003c/sub\u003e@SA composite membrane was investigated. As shown in Fig. 7a, the low viscosity and light oil emulsion (transformer oil) exhibited highest oil rejection percentage of 94.2%, and the oil rejection percentage of the high viscosity and heavy oil emulsions (fire-resistant oil) were slightly lower, but also higher than 92%. When the oil emulsion approached the membrane surface during the separation process, it could easily detach back to the feed emulsion due to the non-sticky property of the superhydrophilic and underwater superoleophobic membrane. (Fig. 7d) (Zhong, et al. 2023). The DLS graphs, photographs, and optical microscopic images of feed and filtrate are shown in Fig. 7b and 7c (Synthetic ester oil as an example). The original emulsion was milky white in color with a wider droplet size distribution ranging from 51 nm to 8825 nm, while the filtrate was transparent in color with large oil droplets are almost non-existent only small droplets are present. The DLS plot of the filtrate only observed a strong peak in the range of 31 ~ 270 nm, which may be due to the presence of emulsifier. The results indicated that the composite membrane show good separation performance on oil-in-water emulsion separation.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eIn summary, a novel SUS membrane was designed by the blending of SA nanofibers with UiO-66-NH2/MgAl-LDH cluster-assembled microsphere, followed by self-polymerization of bioinspired PDA. PDA and U-LDHn cluster-assembled microspheres improve the Ra of the membrane, thus increasing the surface hydrophilicity. The obtained SUS membrane can efficiently separate oil/water mixtures with a high o/w separation efficiency of 99%, with a flux rate of 2661 L m\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e by applying a negative pressure of 0.1 bar. After 10 cycles, the oil-water separation efficiency exceeded 99%, and the water flux always exceeded 2021 L m\u003csup\u003e\u0026minus;\u0026thinsp;2\u003c/sup\u003e h\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e. In addition, the composite membrane has excellent chemical stability, self-cleaning, and anti-fouling properties. Moreover, the membrane showed high oil-in-water emulsion separation efficiency with the oil rejection percentage of 94.2%. This study presents a novel UiO-66-NH\u003csub\u003e2\u003c/sub\u003e/MgAl-LDH@SA composite membrane, offering valuable insights for the treatment of oily water pollution.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003eAuthor contributions\u003c/p\u003e\n\u003cp\u003eJiawen Zhang and Zhenggang Wang wrote the main manuscript text, Jiawen Zhang prepared all figures . Honmei Wang, Jingfeng Zhang and Xichao Liang reviewed the manuscript. Zhuang Fu and Shuang Hu made substantial contributions to the conception and design of the work.\u003c/p\u003e\n\u003cp\u003eFunding\u003c/p\u003e\n\u003cp\u003eThis work was supported by the Natural Science Foundation supported by Hunan Province [grant numbers 2024JJ6027], Hunan Provincial Department of Education Scientific Research Key Project [grant numbers 23A0269], and Changsha University of Science and Technology Graduate Student Research Innovation Project [grant numbers CLKYCX24073].\u003c/p\u003e\n\u003cp\u003eData availability\u003c/p\u003e\n\u003cp\u003eData is provided within the manuscript or supplementary information files.\u003c/p\u003e\n\u003cp\u003eDeclarations\u003c/p\u003e\n\u003cp\u003eConflict of interest\u003c/p\u003e\n\u003cp\u003eThe authors declare no competing interests.\u003c/p\u003e\n\u003cp\u003eHuman and animal rights\u003c/p\u003e\n\u003cp\u003eWe declare that no experiments on animal or human participants were conducted in the study.\u003c/p\u003e\n\u003cp\u003eConsent for publication\u003c/p\u003e\n\u003cp\u003eThe authors have agreed to submit the manuscript to the journal.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eY. Li, H. Zhang, C. Ma, H. Yin, L. Gong, Y. Duh, R. Feng, Durable, cost-effective and superhydrophilic chitosan-alginate hydrogel-coated mesh for efficient oil/water separation, Carbohydrate polymers, 226(2019) 115279.\u003c/li\u003e\n \u003cli\u003eY. Liu, X. Wang, S. Feng, Nonflammable and magnetic sponge decorated with polydimethylsiloxane brush for multitasking and highly efficient oil\u0026ndash;water separation, Advanced Functional Materials, 29(2019) 1902488.\u003c/li\u003e\n \u003cli\u003eA. Xie, J. Cui, J. Yang, Y. Chen, J. Lang, C. Li, Y. Yan, J. Dai, Graphene oxide/Fe (III)-based metal-organic framework membrane for enhanced water purification based on synergistic separation and photo-Fenton processes, Applied Catalysis B: Environmental, 264(2020) 118548.\u003c/li\u003e\n \u003cli\u003eY. Huang, H. Zhan, D. Li, H. Tian, C. Chang, Tunicate cellulose nanocrystals modified commercial filter paper for efficient oil/water separation, Journal of Membrane Science, 591(2019) 117362.\u003c/li\u003e\n \u003cli\u003eW. Zheng, J. Huang, S. Li, M. Ge, L. Teng, Z. Chen, Y. Lai, Advanced materials with special wettability toward intelligent oily wastewater remediation, ACS Applied Materials \u0026amp; Interfaces, 13(2020) 67-87.\u003c/li\u003e\n \u003cli\u003eM. Wu, P. Mu, B. Li, Q. Wang, Y. Yang, J. Li, Pine powders-coated PVDF multifunctional membrane for highly efficient switchable oil/water emulsions separation and dyes adsorption, Separation and Purification Technology, 248(2020) 117028.\u003c/li\u003e\n \u003cli\u003eA. Xie, J. Cui, J. Yang, Y. Chen, J. Lang, C. Li, Y. Yan, J. Dai, Photo-Fenton self-cleaning PVDF/NH2-MIL-88B (Fe) membranes towards highly-efficient oil/water emulsion separation, Journal of Membrane Science, 595(2020) 117499.\u003c/li\u003e\n \u003cli\u003eJ. Yang, J. Cui, A. Xie, J. Dai, C. Li, Y. Yan, Facile preparation of superhydrophilic/underwater superoleophobic cellulose membrane with CaCO3 particles for oil/water separation, Colloids and Surfaces A: Physicochemical and Engineering Aspects, 608(2021) 125583.\u003c/li\u003e\n \u003cli\u003eX. Yue, Z. Li, T. Zhang, D. Yang, F. Qiu, Design and fabrication of superwetting fiber-based membranes for oil/water separation applications, Chemical Engineering Journal, 364(2019) 292-309.\u003c/li\u003e\n \u003cli\u003eW. Zhang, Y. Zhu, X. Liu, D. Wang, J. Li, L. Jiang, J. Jin, Salt‐induced fabrication of superhydrophilic and underwater superoleophobic PAA‐g‐PVDF membranes for effective separation of oil‐in‐water emulsions, Angewandte Chemie International Edition, 53(2014) 856-60.\u003c/li\u003e\n \u003cli\u003eW. Zhang, Y. Liu, F. Tao, Y. An, Y. Zhong, Z. Liu, Z. Hu, X. Zhang, X. Wang, An overview of biomass-based Oil/Water separation materials, Separation and Purification Technology, 316(2023) 123767.\u003c/li\u003e\n \u003cli\u003eJ. Liu, R. Zhang, M. Ci, S. Sui, P. Zhu, Sodium alginate/cellulose nanocrystal fibers with enhanced mechanical strength prepared by wet spinning, Journal of Engineered Fibers and Fabrics, 14(2019) 1558925019847553.\u003c/li\u003e\n \u003cli\u003eM. Ehsan, H. Razzaq, S. Razzaque, M. Kanwal, I. Hussain, Engineering nanocomposite membranes of sodium alginate-graphene oxide for efficient separation of oil-water and antifouling performance, Journal of Environmental Chemical Engineering, 11(2023) 109185.\u003c/li\u003e\n \u003cli\u003eF. Wahid, X.-J. Zhao, Y.-X. Duan, X.-Q. Zhao, S.-R. Jia, C. Zhong, Designing of bacterial cellulose-based superhydrophilic/underwater superoleophobic membrane for oil/water separation, Carbohydrate Polymers, 257(2021) 117611.\u003c/li\u003e\n \u003cli\u003eM. Awwad, M. Bilal, M. Sajid, M.S. Nawaz, I. Ihsanullah, MOF-based membranes for oil/water separation: Status, challenges, and prospects, Journal of Environmental Chemical Engineering, 11(2023) 109073.\u003c/li\u003e\n \u003cli\u003eS. Yu, H. Pang, S. Huang, H. Tang, S. Wang, M. Qiu, Z. Chen, H. Yang, G. Song, D. Fu, Recent advances in metal-organic framework membranes for water treatment: A review, Science of the Total Environment, 800(2021) 149662.\u003c/li\u003e\n \u003cli\u003eA. Elrasheedy, N. Nady, M. Bassyouni, A. El-Shazly, Metal organic framework based polymer mixed matrix membranes: Review on applications in water purification, Membranes, 9(2019) 88.\u003c/li\u003e\n \u003cli\u003eH. Daglar, S. Keskin, Recent advances, opportunities, and challenges in high-throughput computational screening of MOFs for gas separations, Coordination Chemistry Reviews, 422(2020) 213470.\u003c/li\u003e\n \u003cli\u003eL. Wang, M. Zheng, Z. Xie, Nanoscale metal\u0026ndash;organic frameworks for drug delivery: a conventional platform with new promise, Journal of Materials Chemistry B, 6(2018) 707-17.\u003c/li\u003e\n \u003cli\u003eI. Ihsanullah, Applications of MOFs as adsorbents in water purification: Progress, challenges and outlook, Current Opinion in Environmental Science \u0026amp; Health, 26(2022) 100335.\u003c/li\u003e\n \u003cli\u003eS. Shen, Y. Shen, Y. Wu, H. Li, C. Sun, G. Zhang, Y. Guo, Surface modification of PVDF membrane via deposition-grafting of UiO-66-NH2 and their application in oily water separations, Chemical Engineering Science, 260(2022) 117934.\u003c/li\u003e\n \u003cli\u003eX. Zhu, Z. Yu, H. Zeng, X. Feng, Y. Liu, K. Cao, X. Li, R. Long, Using a simple method to prepare UiO‐66‐NH2/chitosan composite membranes for oil\u0026ndash;water separation, Journal of Applied Polymer Science, 138(2021) 50765.\u003c/li\u003e\n \u003cli\u003eT. Kameda, M. Tochinai, S. Kumagai, T. Yoshioka, Mg\u0026minus; Al layered double hydroxide intercalated with CO32\u0026ndash;and its recyclability for treatment of SO2, Applied Clay Science, 183(2019) 105349.\u003c/li\u003e\n \u003cli\u003eM. Everaert, K. Slenders, K. Dox, S. Smolders, D. De Vos, E. Smolders, The isotopic exchangeability of phosphate in Mg-Al layered double hydroxides, Journal of Colloid and Interface Science, 520(2018) 25-32.\u003c/li\u003e\n \u003cli\u003eZ. Tahsiri, M. Niakousari, S. Hosseini, M. Majdinasab, Magnetic layered double hydroxide nanosheet as a biomolecular vessel for enzyme immobilization, International Journal of Biological Macromolecules, 209(2022) 1422-9.\u003c/li\u003e\n \u003cli\u003eY. Cao, A. Khan, T.A. Kurniawan, R. Soltani, A.B. Albadarin, Synthesis of hierarchical micro-mesoporous LDH/MOF nanocomposite with in situ growth of UiO-66-(NH2) 2 MOF on the functionalized NiCo-LDH ultrathin sheets and its application for thallium (I) removal, Journal of Molecular Liquids, 336(2021) 116189.\u003c/li\u003e\n \u003cli\u003eM.A. Iqbal, M. Secchi, M.A. Iqbal, M. Montagna, C. Zanella, M. Fedel, MgAl-LDH/graphene protective film: Insight into LDH-graphene interaction, Surface and Coatings Technology, 401(2020) 126253.\u003c/li\u003e\n \u003cli\u003eZ. Yang, S. Li, X. Xia, Y. Liu, Hexagonal MgAl-LDH simultaneously facilitated active facet exposure and holes storage over ZnIn2S4/MgAl-LDH heterojunction for boosting photocatalytic activities and anti-photocorrosion, Separation and Purification Technology, 300(2022) 121819.\u003c/li\u003e\n \u003cli\u003eJ. Long, Z. Yang, J. Huang, X. Zeng, Self-assembly of exfoliated layered double hydroxide and graphene nanosheets for electrochemical energy storage in zinc/nickel secondary batteries, Journal of Power Sources, 359(2017) 111-8.\u003c/li\u003e\n \u003cli\u003eT. Lu, Y. Sun, M. Shi, D. Ding, Z. Ma, Y. Pan, Y. Yuan, W. Liao, Y. Sun, Ni dopped MgAl hydrotalcite catalyzed hydrothermal liquefaction of microalgae for low N, O bio-oil production, Fuel, 333(2023) 126437.\u003c/li\u003e\n \u003cli\u003eX. Guo, P. Yin, H. Yang, Superb adsorption of organic dyes from aqueous solution on hierarchically porous composites constructed by ZnAl-LDH/Al (OH) 3 nanosheets, Microporous and Mesoporous Materials, 259(2018) 123-33.\u003c/li\u003e\n \u003cli\u003eZ.P. Xu, G.Q. Lu, Hydrothermal synthesis of layered double hydroxides (LDHs) from mixed MgO and Al2O3: LDH formation mechanism, Chemistry of Materials, 17(2005) 1055-62.\u003c/li\u003e\n \u003cli\u003eS. Dong, Y. Jia, X. Xu, J. Luo, J. Han, X. Sun, Crystallization and properties of poly (ethylene terephthalate)/layered double hydroxide nanocomposites, Journal of colloid and interface science, 539(2019) 54-64.\u003c/li\u003e\n \u003cli\u003eH. Li, Y. Yin, L. Zhu, Y. Xiong, X. Li, T. Guo, W. Xing, Q. Xue, A hierarchical structured steel mesh decorated with metal organic framework/graphene oxide for high-efficient oil/water separation, Journal of hazardous materials, 373(2019) 725-32.\u003c/li\u003e\n \u003cli\u003eY. Liao, M. Tian, R. Wang, A high-performance and robust membrane with switchable super-wettability for oil/water separation under ultralow pressure, Journal of Membrane Science, 543(2017) 123-32.\u003c/li\u003e\n \u003cli\u003eQ. Pan, M. Wang, H. Wang, Separating small amount of water and hydrophobic solvents by novel superhydrophobic copper meshes, Applied Surface Science, 254(2008) 6002-6.\u003c/li\u003e\n \u003cli\u003eZ.-M. Zhang, Z.-Q. Gan, R.-Y. Bao, K. Ke, Z.-Y. Liu, M.-B. Yang, W. Yang, Green and robust superhydrophilic electrospun stereocomplex polylactide membranes: Multifunctional oil/water separation and self-cleaning, Journal of Membrane Science, 593(2020) 117420.\u003c/li\u003e\n \u003cli\u003eJ.J. Jiang JingXian, Z.Q. Zhang QingHua, Z.X. Zhan XiaoLi, C.F. Chen FengQiu, A multifunctional gelatin-based aerogel with superior pollutants adsorption, oil/water separation and photocatalytic properties, (2019).\u003c/li\u003e\n \u003cli\u003eP.-B. Li, Y.-X. Wang, Z.-X. Shao, B.-T. Wu, H. Li, M.-M. Gao, K.-G. Liu, K.-R. Shi, Enhanced corrosion protection of magnesium alloy via in situ Mg\u0026ndash;Al LDH coating modified by core\u0026ndash;shell structured Zn\u0026ndash;Al LDH@ ZIF-8, Rare Metals, 41(2022) 2745-58.\u003c/li\u003e\n \u003cli\u003eY. Yousefzadeh, V. Izadkhah, S. Sobhanardakani, B. Lorestani, S. Alavinia, UiO-66-NH2/guanidine-functionalized chitosan: a new bio-based reusable bifunctional adsorbent for removal of methylene blue from aqueous media, International Journal of Biological Macromolecules, 254(2024) 127391.\u003c/li\u003e\n \u003cli\u003eD.L. Zhao, W.S. Yeung, Q. Zhao, T.-S. Chung, Thin-film nanocomposite membranes incorporated with UiO-66-NH2 nanoparticles for brackish water and seawater desalination, Journal of Membrane Science, 604(2020) 118039.\u003c/li\u003e\n \u003cli\u003eW. Ma, N. Zhao, G. Yang, L. Tian, R. Wang, Removal of fluoride ions from aqueous solution by the calcination product of Mg\u0026ndash;Al\u0026ndash;Fe hydrotalcite-like compound, Desalination, 268(2011) 20-6.\u003c/li\u003e\n \u003cli\u003eY. Yang, N. Gao, W. Chu, Y. Zhang, Y. Ma, Adsorption of perchlorate from aqueous solution by the calcination product of Mg/(Al\u0026ndash;Fe) hydrotalcite-like compounds, Journal of Hazardous Materials, 209(2012) 318-25.\u003c/li\u003e\n \u003cli\u003eJ.M. Fern\u0026aacute;ndez, M.A. Ulibarri, F.M. Labajos, V. Rives, The effect of iron on the crystalline phases formed upon thermal decomposition of Mg-Al-Fe hydrotalcites, Journal of Materials Chemistry, 8(1998) 2507-14.\u003c/li\u003e\n \u003cli\u003eS.J. Garibay, S.M. Cohen, Isoreticular synthesis and modification of frameworks with the UiO-66 topology, Chemical communications, 46(2010) 7700-2.\u003c/li\u003e\n \u003cli\u003eY. Su, Z. Zhang, H. Liu, Y. Wang, Cd0. 2Zn0. 8S@ UiO-66-NH2 nanocomposites as efficient and stable visible-light-driven photocatalyst for H2 evolution and CO2 reduction, Applied Catalysis B: Environmental, 200(2017) 448-57.\u003c/li\u003e\n \u003cli\u003eP. Chen, L. Chen, X.a. Dong, H. Wang, J. Li, Y. Zhou, C. Xue, Y. Zhang, F. Dong, Enhanced photocatalytic VOCs mineralization via special Ga-OH charge transfer channel in \u0026alpha;-Ga2O3/MgAl-LDH heterojunction, ACS ES\u0026amp;T Engineering, 1(2020) 501-11.\u003c/li\u003e\n \u003cli\u003eN. Wen, X. Miao, X. Yang, M. Long, W. Deng, Q. Zhou, W. Deng, An alternative fabrication of underoil superhydrophobic or underwater superoleophobic stainless steel meshes for oil-water separation: Originating from one-step vapor deposition of polydimethylsiloxane, Separation and Purification Technology, 204(2018) 116-26.\u003c/li\u003e\n \u003cli\u003eG. Wang, Y. He, H. Wang, L. Zhang, Q. Yu, S. Peng, X. Wu, T. Ren, Z. Zeng, Q. Xue, A cellulose sponge with robust superhydrophilicity and under-water superoleophobicity for highly effective oil/water separation, Green Chemistry, 17(2015) 3093-9.\u003c/li\u003e\n \u003cli\u003eD. Zhong, X. Wang, J. Wang, Green electrospun poly (vinyl alcohol)/silicon dioxide nanofibrous membrane coated with polydopamine in the presence of strong oxidant for effective separation of surfactant-stabilized oil-in-water emulsion, Surface and Coatings Technology, 460(2023) 129421.\u003c/li\u003e\n\u003c/ol\u003e"},{"header":"Scheme ","content":"\u003cp\u003eScheme 1 is are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"cellulose","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cels","sideBox":"Learn more about [Cellulose](https://www.springer.com/journal/10570)","snPcode":"10570","submissionUrl":"https://submission.nature.com/new-submission/10570/3","title":"Cellulose","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false},"keywords":"Sodium alginate fibre, Layered double hydroxide material, UIO-66-NH2, Oil-water separation","lastPublishedDoi":"10.21203/rs.3.rs-6820860/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6820860/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eOil spills and waste oil discharges generate vast quantities of oily wastewater, posing severe ecological and environmental challenges while also endangering human health, which necessitates the development of advanced and efficient oil-water separation membranes. In this work, a novel sodium alginate fiber (SA) based superhydrophilic/underwater superoleophobic (SUS) membrane was developed for o/w separation through a facile method by blending SA nanofibers with UiO-66-NH\u003csub\u003e2\u003c/sub\u003e/MgAl-LDH cluster-assembled microsphere. The micron-scale spheres were embedded within SA nanofibers, inducing the formation of a loosely stacked nanofiber structure, thereby enhancing water permeability. The obtained composite membrane exhibited good o/w separation performance with a high separation efficiency of \u0026gt;99% and a flux rate of ~2661 L m\u003csup\u003e-2\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e. Moreover, The underwater oil contact angle (OCA) of U-LDHn@SA composite membrane were all around 140°, which indicated that U-LDHn@SA composite membrane has good underwater superoleophobicity. After 10 cycles, the oil-water separation efficiency exceeded 99% and the water flux always exceeds 2021 L m\u003csup\u003e-2\u003c/sup\u003e h\u003csup\u003e-1\u003c/sup\u003e. The compose membrane also exhibited the potential to separate oil-in-water emulsion with the highest oil rejection of 94%. The membrane showed antifouling properties, recyclability, and stability in harsh conditions. This work provides a new idea for the development of oil-water separation membranes with practical applications.\u003c/p\u003e","manuscriptTitle":"Preparation of UiO-66-NH 2 /MgAl-LDHs @ Sodium Alginate Fiber Membrane and Determination of Oil Water Separation Performance","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-01 10:37:17","doi":"10.21203/rs.3.rs-6820860/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-14T21:52:19+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-06-14T18:42:10+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-06-06T09:31:33+00:00","index":"","fulltext":""},{"type":"submitted","content":"Cellulose","date":"2025-06-04T12:54:44+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"cellulose","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"cels","sideBox":"Learn more about [Cellulose](https://www.springer.com/journal/10570)","snPcode":"10570","submissionUrl":"https://submission.nature.com/new-submission/10570/3","title":"Cellulose","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"em","reportingPortfolio":"Springer Hybrid","inReviewEnabled":true,"inReviewRevisionsEnabled":false}}],"origin":"","ownerIdentity":"90fe3d21-6d59-43f3-ad54-0f704f6ccb16","owner":[],"postedDate":"July 1st, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-12-08T16:07:30+00:00","versionOfRecord":{"articleIdentity":"rs-6820860","link":"https://doi.org/10.1007/s10570-025-06875-3","journal":{"identity":"cellulose","isVorOnly":false,"title":"Cellulose"},"publishedOn":"2025-12-03 15:58:15","publishedOnDateReadable":"December 3rd, 2025"},"versionCreatedAt":"2025-07-01 10:37:17","video":"","vorDoi":"10.1007/s10570-025-06875-3","vorDoiUrl":"https://doi.org/10.1007/s10570-025-06875-3","workflowStages":[]},"version":"v1","identity":"rs-6820860","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6820860","identity":"rs-6820860","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}