Effects of surface modification with Glutaraldehyde/Nanoclay/Styrene on Poplar Wood Performance

Effects of surface modification with Glutaraldehyde/Nanoclay/Styrene on Poplar Wood 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 Effects of surface modification with Glutaraldehyde/Nanoclay/Styrene on Poplar Wood Performance Raoufeh Abedini, Fatemeh Shahi, Maryam Ghorbani, Seyed Mojtaba Amininasab This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7387162/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Limited application of fast-growing species due to dimensional changes and low mechanical strength can be expand by modification methods. In this study, the effect of surface modification with aldehydes/nanoparticles/polymer on chemo/physico/mechanical properties of poplar ( Populus Spp .) wood was investigated. For this purpose, specimens were modified with 20% Glutaraldehyde (GA) solution, without and with nano clay (NC) (in 1% and 2%), and subsequently with styrene (St) for combined modification. According to Fourier-transform infrared (FTIR) spectroscopy results, changes of chemical structure confirmed the reaction of GA with wood. Scanning electron microscopy (SEM) images showed reducing of vessels pit aperture size by GA modification and forming a layer of St on the internal surface of lumens, which resulted in less hygroscopicity for modified specimens. The highest dimensional stability was calculated for GA/St and GA/NC/St modified specimens. GA modification enhanced the photostability of wood exposed to accelerated weathering, and this feature was intensified with adding NC. GA modification increased surface roughness and subsequently contact angle of specimens, which was more obvious by adding NC. GA significantly improved the hardness of specimens, and the highest modulus of bending was measured for GA/St modified wood. Finally, it could be concluded that GA/NC/styrene modification is a promising method for enhancing dimensional stability and weathering resistance of poplar wood, but for efficient strengthening of GA modified wood, styrene impregnation under pressure is suggested. poplar wood surface chemical modification glutaraldhyde chemo/physico/mechanical properties weathering resistance Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 1 Introduction Wood is considered as an important building material for interior and exterior applications (Acosta et al. 2021 ), owing to its renewability, sustainability, easy processing, aesthetic appeal and high strength-to-weight ratio properties (Lopez-Gomez et al. 2025 ; Sun et al. 2016 ). However, some inherent defects of light-fast growing species, such as susceptibility to dimensional changes at different relative humidity and low mechanical strength, restrict their industrial applications (Acosta et al. 2021 ). Studies on enhancing wood properties by variety of methods can be summarized into four approaches: blocking hydroxyl groups of wood components, using low surface energy materials, improving wood surface roughness, and filling the wood cell cavities. Surface modification by different techniques such as mechanical, thermal and chemical modification, can enhance the physical and mechanical properties of wood (Hill 2006 ; Petric 2013 ). Chemical modification is an effective method for improving the dimensional stability, via crosslinking to the hydroxyl groups of wood components (Hill 2006 ; Sun et al. 2016 ; Che et al. 2019 ). Glutaraldehyde (GA) as an aldehyde, can improve the dimensional stability, durability, and hydrophobicity of wood by chemical modification through crosslinking to the wood structure (Sun et al. 2016 ; Xiao et al. 2012 ; Xie et al. 2011 ). Since the porous structure of the GA modified wood is still empty, several studies have been conducted for introducing an efficient mechanism followed by cell wall modification such as: filling porosity with wax (Scholz et al. 2012 ) and oil (Mohebby et al. 2014 ), or in situ polymerization of monomers (Li et al. 2013 ; Devi and Maji 2013 ). In situ polymerization, despite the retarding water absorption (Ermeydan et al. 2014 ; Li et al. 2013 ) and enhancing some of mechanical properties, such as stiffness and flexural strength (Che et al. 2019 ; Sun et al. 2016 ), could not resistance expose weathering (Liu and Hu 2021 ; Ermeydan et al. 2020 ). According to the literatures, for improving the wood resistance to weathering parameters such as UV, various nanoparticles including TiO2, ZnO, SiO2 and nano clay could be used (Marzi, 2015 ; Devi and Maji 2013 ; Fufa et al. 2012 ). Nanoclay is a low cost, available, and safe nanoparticle, which improves stiffness, toughness, heat resistance, and flame resistance of wood composites (Frigione and Lettieri 2018 ). Accordingly, this research was conducted to develop a multifunctional surface modification by clay nanoparticles/ glutaraldehyde/styrene for enhancing the physicomechanical properties and photo stability of resultant product. 2 Material and Methods 2.1 Materials Glutaraldehyde 50% in aqueous solution and acetone were from Daejung (Seohaean- Siheung-si, Gyeonggi-do, Korea); Nano clay (Montmorillonite) and Benzoyl peroxide were purchased from Sigma-Aldrich and CDH (India), respectively. Styrene was prepared by Tabriz petrochemical co. (Iran); and Sodium acetate, Acetic acid and magnesium chloride were also produced by Kimia chemicals (Iran). Poplar wood ( Populus deltoeides ) was harvested from a local forest in north of Iran, Sari. specimens were prepared from clear, defect free wood for physical, weathering and mechanical tests according to ASTM D4442-92 (2003), ASTM G154 (2006) and ASTM ASTM D143-14 (2014), respectively. In addition to control specimens, five replicate specimens were oven dried at 103 ± 2°C and weighed for each of the modified woods. Experimental specimens were randomly separated according to Table 1 . Table 1 code of experimental treatments Treatment Code Control C Glutaraldehyde treated GA Glutaraldehyde/ 1% nano clay GN1 Glutaraldehyde/ 2 nano clay GN2 Glutaraldehyde/Styrene GS Glutaraldehyde/1% nano clay/Styrene GN1St Glutaraldehyde/2% nano clay/Styrene GN2St 2.2 Methods 50% GA solution was diluted to 20% solution by 0.1 molar sodium acetate buffer and acetic acid as a pH adjuster. Magnesium chloride was added to GA solution at 12.5 wt% as catalyst. For preparing the glutaraldehyde/nano clay (GA/NC) solution, 1 and 2 wt% nono clay was added to GA solution and was ultrasound in 30 minutes for preventing the NC sediment. Specimens were immersed in modifiers for 24 h, then removed from solution, wrapped in aluminums foils and heated at 120°C for 48 h. After unwrapping, the modified specimens were dried for 24 h at 103°C. For GA/NC/styrene (St) modification, GA/NC modified specimens immersed in 20% St/acetone solution containing benzoyl peroxide 2wt% as initiator for 24 h, then wrapped in aluminum foil and heated at 90°C for 24 h to cure the styrene. Finally, the modified specimens were weighed, and the amount of weight percent gain (WPG) was evaluated according to Eq. (1): Weight gain = W 1 – W 0 / W 0 × 100 (1) Where W 0 and W 1 are weight of specimens before and after modification (g). 2.3 Characterization of modified wood 2.3.1 Fourier Transform Infrared Analysis For evaluating the chemical structure, the FTIR Spectroscopy was conducted on the surface of control and modified specimens, before and after exposing UV radiation, using an Agilent cary630 FTIR spectrometer (Agilent Co., USA) in the attenuated total reflectance (ATR) mode. The resulting spectra were recorded in the range of 400 and 4000 cm − 1 with a resolution of 4 cm − 1 . 2.3.2 Morphological characterization Morphological features of untreated and treated specimens were examined using scanning electron microscope (SEM). Before applying the surface modification and coating, the transvers and tangential surfaces of the specimens were cut with a surgery blade to obtain smooth and fuzzy-free surfaces. After developing a hierarchical structure based on styrene coating on nanoparticles/glutaraldehyde modified wood, the specimen was mounted on the holder with a double-sided adhesive tape, gold sputter-coated and observed with an electron microscope (SNE-4500 M, Korea). 2.3.3 Physical Properties The physical properties of modified and control specimens were calculated by soaking them in deionized water during 168 h at room temperature. Water absorption (WA), water repellent efficiency (WRE), volumetric swelling (VS), and anti-swelling efficiency (ASE) were determined according to Eqs. 2 to 5: WA = W 1 – W 0 / W 0 × 100 (2) where W 0 and W 1 are the weight of the specimens before and after soaking in water (g), respectively. WRE = WA c – WA m / WA c × 100 (3) where WA c and WA m represent water absorption of control and modified specimens. VS = V 1 – V 0 / V 0 × 100 (4) where V 1 and V 0 are the volume after and before soaking in water (cm 3 ). ASE = S c – S m / S 1 × 100 (5) where S c is the volume swelling of control specimens (%), and S m is the volume swelling of the modified specimens (%). 2.3.4 Accelerated weathering The photostability of the specimens were evaluated by a chamber fabricated with S304 stainless steel internal walls. For simulating the harm of sunshine, Four UVA-340 W lamps (Philips F40T12/BL) with wavelength region from 365 nm to 295 nm and peak emission of 340 nm were used as light sources. The distance between each lamps, and lamp and specimens were 10 cm and 7 cm, respectively. This test was consisted of a continuous light irradiation for 300 hours on the specimen's surface. 23.5 Color Measurement The color of control and modified specimens, before and after weathering, was assessed using a ZB-A Colorimeter (Hangzhou Zhibang Automated Technology Co., China) in the CIELAB color system at three positions on the tangential surface of each specimen. This instrument provided the numerical values of L* (lightness intensity from zero: black to 100: white), a* (the color coordinate in pure green: -120 –pure red: +120), b* (the color chroma on the pure yellow: +120 –pure blue axis: -120). To compare the color changes after weathering, three factors, ΔL* as the lightness change, Δa* and Δb* as the color coordinates changes, and ΔE* as the overall color change were calculated using Eqs. 6–9. Δ L = L f – L i (6) Δ a = a f – a i (7) Δ b = b f – b i (8) Δ E = [Δ L 2 + Δ a 2 + Δ b 2 ] 1/2 (9) where the indexes of i and f introduce color changes before and after weathering. 2.3.6 Surface roughness test Surface roughness was measured perpendicular to grain of specimens using a Mahr Perthometer m3 instrument (Göttingen, Germany) with a tip radius of 2 µm and active tracing length of 17.5 mm. Each measurement was represented by the calculated roughness parameters R a (average roughness), R z (roughness depth: mean height of 10 point from profile), and R max (maximum roughness). Three tracing were made on each measuring surface. 2.3.7 Wettability Water contact angles (WCAs) on the surface of control and modified specimens were measured to evaluate the effect of modification on the wettability. Images of water droplets (about 4 µl) on the specimen’s surface, were captured at intervals of 10s for a total duration of 120s, using a digital microscope (Dino-lite AM7915MZTL, Taiwan) that was connected to a computer supported by Dinocapture 2.0 version 1.5.36 software. For every type of modifications, three specimens were tested, and WCA was determined on three spots of tangential surface of each specimen. Finally, images were analyzed by ImageJ software to determine contact angle. 2.3.8 Mechanical Properties Mechanical properties, including bending properties (strength (MOR) and modulus (MOE)) and hardness were tested according to ASTM D143-14 (2014), using a SANTAM STM-20 machine (Santam Co., Iran). 2.4 Statistical Analysis A complete randomized design and Duncan grouping were used to evaluate the effect of different surface modifications on the properties of poplar wood. Statistical analysis was conducted using SPSS software program, version 17.0 (IBM Corp., Armonk, NY, USA). 3 Results and discussion 3.1 Morphology Fig. 1 shows the scanning electron micrographs of the control and modified specimens. Transverse and tangential surfaces of the control specimens are respectively, presented in Figure 1(a) and (b), in which vessel and fiber lumens are completely empty and inter-vessel pits are open. The porous structure of the glutaraldehyde-modified wood was maintained (Sun et al. 2016) (Fig. 1(c)), but in contrast with control, reducing the aperture of inter-vessel pits in the tangential surface confirm the bulking of the cell walls (Figure 1(d)). It confirms that the majority of the glutaraldehyde molecules reacted with the cell wall polymers and resulted in cell wall bulking. Deposition of nanoparticles in fibers (Fig. 1(e)) and internal wall of the vessel (Fig. 1(f)) are evident. 20% Styrene solution polymerized as a layer on the inner surface of the fibers and the vessels (Fig. 1h). The layers formed by styrene on the clay nanoparticles/glutaraldehyde modified structure, covered the pits of the cell walls (Fig. 1i & j). 3.2 Surface chemistry Fig. 2 illustrates the infrared spectra of all specimens before and after UV irradiation. The band at 3350 cm -1 attributed to the hydroxyl groups of alcohol, phenol, and acids (Sun et al. 2016; Xing et al. 2015), significantly reduced for GN1St and GN2St specimens due to the reaction of free −OH groups with GA’s aldehyde groups and forming covalent bonds. The peak within the range of 2780 to 3000 cm -1 is associated to the C-H stretching in the styrene polymer and methyl/methylene groups of the wood. The peak at 1735 cm⁻¹ assigned to C=O stretching in esters, aldehydes, and ketones (Sun et al. 2016; Xing et al. 2015), shifts to 1717 cm⁻¹ in glutaraldehyde-modified specimens subsequent to ketone formation (R–CO–R). Enhancing the intensity of this peak for glutaraldehyde/styrene specimens indicates a greater contribution from carbonyl groups (Devi and Maji, 2013). 1418 cm -1 peak related to the nanoclay carbonate content intensified with nanoparticle loading. In glutaraldehyde-treated wood, OH bending vibrations of cellulose/hemicellulose at 1317 cm -1 , diminished due to –OH reaction with aldehydes. 1230 cm -1 peak related to the formation of methylene ether bridges (-RCH-O-CHR-) (Xi et al. 2018) reduced in GN1 and GA treatments. Peaks at 1030–1050 cm -1 (aliphatic alcohols/ethers) and 1160 cm -1 (C–O–C stretching) confirmed the reaction of hydroxyl groups of wood with glutaraldehyde via formation of acetal bonds (Sun et al. 2016). The montmorillonite consists of approximately 43% SiO2, 16% AL2O3, and other elements such as Fe2O3 and MgO (Komatsu et al. 2016). In all nanoparticle-treated specimens, peaks in the range of 1870 cm -1 and 770 cm -1 confirmed the presence of clay nanoparticles in the modified wood substrate (Devi and Maji, 2013). After 300 hours of UV irradiation, the combined nano clay/glutaraldehyde (GA) modification significantly improved photostability, as demonstrated by the stability observed in the FTIR spectra of modified specimens. The hydroxyl group vibrations (3400 cm -1 region) exhibited negligible changes upon UV irradiation. The intensity of the C-H stretching vibration of methylene groups (2933 cm -1 ) decreased in all specimens upon UV irradiation, consistent with previous findings (Nguyen et al. 2016). The carbonyl stretching vibration peak at 1731 cm -1 increased significantly in the control specimens, whereas the modified specimens showed negligible changes in this spectral region. This phenomenon results from photooxidative degradation, wherein UV irradiation breaks down the lignin and cellulose polymer chains, and subsequently increased the carbonyl index (Devi and Maji 2013; Teacă et al. 2013). According to the literatures, clay nanoparticles as UV stabilizers, in combination with vinyl polymers, effectively reduced the carbonyl index intensity and inhibited photodegradation (Devi and Maji 2013). The intensity of lignin's aromatic vibrations at 1607 cm -1 and 1506 cm -1 decreased significantly in control specimens, indicating their susceptibility to photodegradation (Teacă et al. 2013). Glutaraldehyde (GA) modification, likely through the chemical blocking of reactive phenolic groups, protected lignin against degradation (Xiao et al. 2012). 3.3 Color changes Table 2 shows the color index of control and modified specimens before and after UV irradiation. The modification induced darkening on all specimens relative to the controls, and the GN2St combined modification exhibited the most pronounced effect, which quantitatively confirmed by the significant reduction in the L* index values. Darkening effect of styrene has previously reported for pine wood (Acosta et al. 2021). The modification resulted in a significant increase in a* (yellowness) and b* (redness) index. Unlike the modified specimens, weathering significantly changed color of the control specimen, with increasing a* and the b* indexes from 6.35 to 12 and 34.47 to 62.32, respectively. With the exception of the control specimen, weathering significantly increased the L* index (lightness) in all modified specimens. Degradation of cell wall polymers in the control specimens was identified as a key factor contributing to their color darkening (Ermeydan et al. 2020). ∆E* value represents the overall change of surface color, resulting from changes in all color indexes. The control specimens exhibited the most pronounced total color change following UV irradiation, primarily due to lignin's strong UV absorption capacity and subsequent degradation of its chromophoric groups (Che et al., 2019; Xiao et al. 2012). Modification with glutaraldehyde, particularly in the presence of 1% clay nanoparticles, mitigated these alterations. Xiao and the coworkers also reported a reduction in lignin and hemicellulose degradation of GA-modified wood following weathering (Xiao et al. 2012). The enhanced photostability of lignin in GA-modified wood was attributed to the blocking of lignin's phenolic groups by glutaraldehyde (Xiao et al. 2012). Modification with styrene, with the exception of GN1St, resulted in more pronounced surface color changes. According to literatures, polystyrene rapidly undergoes a yellowing reaction exposed to UV light (Ermeydan et al. 2020). The specimens modified with clay nanoparticles at a concentration of 1% (GN1St and GN1) exhibited the least color change after weathering. However, increasing the concentration of nanoclay to 2% resulted in a higher color change, likely attributable to agglomeration of clay nanoparticles. Fufa and coworkers similarly demonstrated that the nanoparticles markedly diminished color changes of weathered specimens (Fufa et al. 2012). Previous studies have demonstrated that the nanoclay and nanotitanium, at 0.5% concentration improved wood's photostability more effectively than higher concentrations (Devi and Maji 2013). Table 2 Color parameters after UV irradiation Before irradiation After irradiation Sample code L* a* b* L* a* b* ∆E* C 66.53 (0.27) 6.35 (0.49) 34.47 (0.11) 60.72 (0.27) 12.02 (0.41) 62.32 (0.7) 29.02 G 57.41 (0.27) 17.99 (0.99) 59.62 (0.08) 60.20 (0.45) 18.16 (0.6) 61.55 (0.49) 3.43 GN1 61.63 (0.21) 17.02 (0.87) 61.09 (0.76) 64.55 (0.18) 16.44 (0.3) 61.89 (0.4) 3.24 GN2 59.57 (0.24) 16.81 (0.18) 59.83 (0.59) 63.78 (0.32) 16.50 (0.11) 62.33 (0.6) 4.93 GS 55.11 (0.23) 21.98 (0.45) 60.51 (0.23) 60.68 (0.33) 19.79 (0.25) 62.51 (1.4) 6.39 GN1St 60.68 (0.21) 15.70 (0.19) 60.57 (0.39) 63.28 (0.18) 15.59 (0.15) 58.85 (1.03) 3.28 GN2St 51.23 (0.37) 21.83 (0.55) 58.33 (0.34) 57.81 (0.6) 19.07 (0.13) 59.06 (2.19) 7.47 Note: The data in parenthesis refers to the standard deviations 3.4 Physical properties Figures 3–5 present the physical property results of the control and modified specimens. The bulking coefficient of the GA-modified specimen (6.1%), which is the only chemical reactive with the wood in this study, confirmed the penetration of polar GA into the wood cell walls, without applying pressure. A significant difference was observed in the weight percent gain (WPG) between specimens modified with GA and those modified with GA/styrene (fig. 3), which increased by nanoparticles. The highest total weight percent gain was calculated for GN1St and GN2St. However, WPG of styrene decreased with higher nanoparticle concentration, probably due to nanoparticles agglomeration, which may physically block the pathways of styrene penetration. Water absorption and swelling analyses demonstrated that GA modification effectively enhanced both hydrophobicity and dimensional stability. According to the results of water absorption and swelling, glutaraldehyde modification improved both hydrophobicity and dimensional stability of the resulting product, without significant enhancement with addition of nanoclay (Fig. 4a&b). Impregnation with styrene significantly reduced water absorption and dimensional changes for all specimens and the lowest water absorption was measured for GS modified specimens (Fig. 4a). Glutaraldehyde, as a dialdehyde, reacts with one and two hydroxyl groups of wood to form hemiacetal and acetal, respectively. Under hydrolytic conditions, the acetal demonstrates significantly greater stability compared to the hemiacetal (Xie et al. 2011). The combination of hydroxyl groups blocking and cell wall bulking by glutaraldehyde, accompanied with porosity reduction via styrene polymerization reduced the water absorption (Ermeydan et al. 2020; Che et al. 2019; Sun et al. 2016; Ermeydan et al. 2014). 3.5 Roughness Surface roughness plays a critical role in coating adhesion to wood substrate (Hang et al. 2024). According to the results, the effect of modification on surface roughness was statically significant (Table 3). The highest roughness was observed in the GN1 and GN1St specimens, whereas the lowest was recorded for the control ones. Glutaraldehyde modification significantly increased surface roughness, although this effect has not been previously reported in the literature. The roughness parameters increased significantly in specimens containing 1% nano clay, but decreased with increasing nanoparticle concentration to 2%. Probably, the higher concentration of nanoparticles promoted more uniform surfaces by filling the pores, thereby reducing surface roughness. The addition of styrene had no significant effect on surface roughness of GA modified specimens. Table 3 Surface roughness parameters of untreated and modified specimens 3.6 Wettability Contact angle measurements revealed a significant reduction in wettability for the modified specimens (Fig. 5). In contrast to the GN1St specimens, which exhibited the highest contact angles, the control specimens showed the lowest contact angle values. Wood modification with glutaraldehyde increased the contact angle by reducing hydroxyl groups and porosity, followed by the bulking of the wood cell wall. The addition of nano clay into the glutaraldehyde enhanced the water contact angle on the modified specimens, which could be attributed to the increase in surface roughness. The GN2 specimen exhibited an initial contact angle of 125°, which underwent rapid reduction, ultimately reaching the lowest value among all modified samples within 120 seconds. This rapid reduction could be attributed to the reduction in surface roughness caused by nanoparticle agglomeration. Combining chemical modification/nanoparticles with styrene demonstrated both higher and more stable contact angles, suggesting the polymeric matrix effectively immobilized the nanoparticles and blocked the path of water penetration (Acosta et al. 2021). 3.6 Mechanical properties In this study, the effect of modification on some mechanical properties including hardness and bending was measured. Material resistance to local and bulk deformation is represented by hardness and the modulus of elasticity, respectively (Yadav and Yusoh 2019). Surface modification with GA increased the hardness (Fig. 6). This increment could be attributed to the crosslinking of microfibrils with glutaraldehyde, resulting in enhanced cell wall hardness (Xiao et al. 2010). Adding nanoparticles and styrene did not create a significant increase in hardness compared to GA modified specimens. However, elevated nanoparticle concentration, with or without styrene, reduced hardness to the extent that no statistically significant difference remained between the modified surface and the control specimen (Yadav and Yusoh 2019). GA modification significantly reduced the modulus of rupture (MOR) while having no statistically significant effect on the modulus of elasticity (MOE) (Fig.7 a&b). These findings align with earlier studies on scot pine GA modified wood (Lopez-Gomez et al. 2025; Sun et al. 2016). Compared to control specimens, GA/nanoclay modification enhanced the modulus of elasticity (MOE) (GN1 and GN2). The addition of styrene enhanced the MOE of the GA modified specimens, whereas this property decreased in the GA/nanoclay modified ones. Consistent with our findings, Che and coworkers documented that styrene incorporation increased the modulus of elasticity (MOE) through its reinforcing role within wood cell cavities (Che et al. 2019). Yadav and Yusoh (2019) reported an increase in the elastic modulus at 1% nanoclay loading, while a followed by a progressive decrease at higher concentrations up to 2.5%. Unlike MOE, MOR decreased after modification, with no significant differences observed among the different groups. The reduction in MOR following GA modification can be attributed to the restricted mobility of wood cell wall polymers caused by GA crosslinking within the cell wall (Xiao et al. 2010; Sun et al. 2016). The GA/styrene modification enhanced wood stiffness. Because MOR is more sensitive to stiffness changes than MOE (Sun et al. 2016), the GA/styrene ultimately reduced the flexural strength of the final product. 4 Conclusion Scanning electron micrographs confirmed the cell wall bulking following GA modification, along with styrene coating on the inner surface of the fibers. Clay nanoparticles penetrated the pit membrane, however, their penetration and overall effectiveness decreased at higher concentration due to increased agglomeration tendency. According to the FTIR spectra, nanoclay/GA increased the photostability of the modified specimens. While glutaraldehyde limited lignin degradation, styrene-modified specimens exhibited rapid yellowing upon UV exposure, and requires additional protective for outdoor applications. GA/styrene reduced water absorption and dimensional changes. Although styrene did not form direct bonds with the cell wall, its penetration into the nonpolar cell wall components following GA modification improved the anti-swelling efficiency. Surface modification with glutaraldehyde/1% nanoclay/styrene increased the water contact angle and reduced surface wettability through enhanced surface roughness. Surface modification with GA increased the hardness, but the nanoparticles and styrene showed no statistically significant enhancement in the hardness of GA-modified specimens. While GA/nanoclay enhanced MOE, subsequent styrene addition further increased MOE in GA-modified specimens, but reduced it in GA/nanoclay-modified samples. Following modification, MOR exhibited a decrease, with no statistically significant differences between treatment groups. It is suggested that the effects of pressure processes be investigated to substantially enhance this resistance. Declarations Author contributions Raoufeh Abdini planned and supervised the project, performed the data analyses, and writing the manuscript. Fatemeh Shahi produced the test specimens and carried out the experiments. Maryam Ghorbani designed, conceived the original idea, advised the project and reviewed and edit the manuscript. Seyed Mojtaba Amininasab planned and advised the project. Funding The authors did not receive support from any organization for the submitted work. Data availability No datasets were generated or analysed during the current study. Conflict of interest The authors declare no competing interests. References Acosta AP, Delucis AR, Amico SC, Gatto DA (2021) Fast-growing pine wood modified by a two-step treatment based on heating and in situ polymerization of polystyrene. Construction and Building Materials 302: 1-11. https://doi.org/10.1016/j.conbuildmat.2021.124422 American Society for Testing and Materials (2014) ASTM D143: Standard test methods for small clear specimens of timber. ASTM International , West Conshohocken, PA, USA. American Society for Testing and Materials (2006) ASTM G154: Standard practice for operating fluorescent light apparatus for UV exposure of nonmetallic materials. ASTM International , West Conshohocken, PA, USA. American Society for Testing and Materials (2003) ASTM D4442: Standard test methods for direct moisture content measurement of wood and wood-base materials. ASTM International , West Conshohocken, PA, USA. Chang TC, Chang HT, Wu CL, Lin HY, Chang ST (2010) Stabilizing effect of extractives on the photooxidation of Acacia confusa wood. Polym Degrad Stab 95:1518-1522. https://doi.org/10.1016/j.polymdegradstab.2010.06.012 Che W, Xiao Z, Wang Z, Nguyen TT, Xie Y (2019) Enhanced weathering resistance of radiata pine wood by treatment with an aqueous styrene/acrylic acid copolymer dispersion. Journal of Wood Chemistry and Technology 39:1-15. https://doi.org/10.1080/02773813.2019.1636824 Devi RR, Maji TK (2013) In situ polymerized wood polymer composite: effect of additives and nanoclay on the thermal and mechanical properties. Materials Research 16:954-963. https://doi.org/10.1590/S1516-14392013005000071 Ermeydan MA, Babacan M, Tomak ED (2020) Evaluation of dimensional stability, weathering and decay resistance of modified pine wood by in-situ polymerization of styrene. Journal of Wood Chemistry and Technology 40(5):1-12. https://doi.org/10.1080/02773813.2020.1786127 Ermeydan MA, Cabane E, Gierlinger N, Koetz J, Burgert I (2014) Improvement of wood material properties via in situ polymerization of styrene into tosylated cell walls. Royal Society of Chemistry 4:12981-12988. https://doi.org/10.1039/c4ra00741g Frigione M, Lettieri M (2018) Novel attribute of organic-inorganic hybrid coatings for protection and preservation of materials (stone and wood) belonging to cultural heritage. Coatings 8(9):319. https://doi.org/10.3390/coatings8090319 Fufa SM, Jelle BP, Hovde PJ, Rorvik PM (2012) Coated wooden cladding and the influence of nanoparticles on the weathering performance. Progress in Organic Coatings 75:72-78. https://doi.org/10.1016/j.porgcoat.2012.03.010 Hang J, Yan X, Li J (2024) A review on the effect of wood surface modification on paint film adhesion properties. Coatings 14(10):1313. https://doi.org/10.3390/coatings14101313 Hill CAS (2006) Wood Modification Chemical, Thermal and other Processes. John Wiley & Sons, Hoboken. https://doi.org/10.1002/0470021748 Komatsu LGH, Oliani WL, Lugao AB, Parra DF (2016) Nanocomposites of irradiated polypropylene with clay are degradable? Radiation Physics and Chemistry 118:11-15. https://doi.org/10.1016/j.radphyschem.2015.06.004 Li Y, Dong X, Lu Z, Jia W, Liu Y (2013) Effect of polymer in situ synthesized from methyl methacrylate and styrene on the morphology, thermal behavior and durability of wood. Journal of Applied Polymer Science 128(1): 13-20. https://doi.org/10.1002/app.38099 Liu Y, Hu J (2021) Investigation of polystyrene-based microspheres from different copolymers and their structural color coatings on wood surface. Coatings 11:14. https://doi.org/10.3390/coatings11010014 Lopez-Gomez YM, Nissinen VH, Barbero-Lopez A, Venalainen M, Haapala A (2025) Assessment of glutaraldehyde and formaldehyde for enhancing decay resistance and reducing caffeine leachability in Scots pine wood. International Biodeterioration & Biodegradation 198: 0964-8305. https://doi.org/10.1016/j.ibiod.2025.106014 Marzi T (2015) Nanostructured materials for protection and reinforcement of timber structures: a review and future challenges. Construction and Building Materials 97:119-130. https://doi.org/10.1016/j.conbuildmat.2015.07.016 Mohebby B, Kevily H, Kazemi-Najafi S (2014) Oleothermal modification of fir wood with a combination of soybean oil and maleic anhydride and its effects on physico-mechanical properties of treated wood. Wood Science and Technology 48:797-809. https://doi.org/10.1007/s00226-014-0640-5 Nguyen TV, Nguyen TA, Dao PH, Mac VP, Nguyen AH, Do MT, Nguyen TH (2016) Effect of rutile titania dioxide nanoparticles on the mechanical property, thermal stability, weathering resistance and antibacterial property of styrene acrylic polyurethane coating. Advances in Natural Sciences: Nanoscience and Nanotechnology 7:045015. https://doi.org/10.1088/2043-6262/7/4/045015 Petric M (2013) Surface modification of wood: A critical review. Reviews of Adhesion and Adhesives 1(2): 216-247. https://doi: 10.7569/RAA.2013.097308 Schneider MH, Phillips JG, Lande S (2000) Physical and mechanical properties of wood polymer composites. Journal of Forest Engineering 11:83-89. https://doi.org/10.1080/08435243.2000.10702748 Scholz G, Krause A, Militz H (2012) Full impregnation of modified wood with wax. European Journal of Wood and Wood Products 70:91-98. https://doi.org/10.1515/hf-2016-0063 Sun W, Shen H, Cao J (2016) Modification of wood by glutaraldehyde and poly (vinyl alcohol). Materials & Design 96: 392-400. https://doi.org/10.1016/j.matdes.2016.02.044 Teacă CA, Roşu D, Bodîrlău R, Roşu L (2013) Structural changes in wood under artificial UV light irradiation determined by FTIR spectroscopy and color measurements - A brief review. BioResources 8(1):1478-1507. https://doi.org/10.15376/biores.8.1.1478-1507 Xiao Z, Xie Y, Mai C (2012) The fungal resistance of wood modified with glutaraldehyde. Holzforschung 66:237-243. https://doi.org/10.1515/HF.2011.138 Xiao Z, Xie Y, Militz H, Mai C (2010) Effects of chemical modification with glutaraldehyde on the mechanical properties of wood. Holzforschung 64:475-482. https://doi.org/10.1515/HF.2010.058 Xi X, Pizzi A, Amirou S (2018) Melamine-glyoxal-glutaraldehyde wood panel adhesives without formaldehyde. Polymers 10(1):1-18. https://doi.org/10.3390/polym10010022 Xie Y, Hill CAS, Xiao Z, Mai C, Militz H (2011) Dynamic water vapour sorption properties of wood treated with glutaraldehyde. Wood Science and Technology 45:49-61. https://doi.org/10.1007/s00226-010-0311-0 Xing D, Wang S, Li J (2015) Effect of artificial weathering on the properties of industrial-scale thermally modified wood. BioResources 10(4):8238-8252. https://doi.org/10.15376/biores.10.4.8238-8252 Yadav SM, Yusoh KB (2019) Subsurface mechanical properties and subsurface creep behavior of modified nanoclay-based wood-plastic composites studied by nanoindentation. Polymer Bulletin 76(1):2179-2196. https://doi.org/10.1007/s00289-018-2497-5 Additional Declarations No competing interests reported. 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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-7387162","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":514838368,"identity":"7fbe3a74-43d1-4c15-8bff-c71d53556975","order_by":0,"name":"Raoufeh Abedini","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3ElEQVRIiWNgGAWjYHACNiCSYGBjb0AIHSBOCw+SOmK0ACmJBCJdZd7A/OzBhzKLPD7J5w8/F+45zMDffoDxcAUeLTIH2MwNZ5yTKGaTzjGWnvHsMIPEmQSGg2fwaJFgYDCT5m2TSGyTzmGQ5jlwmIHhBgPDwQa8Wti/Sf8FaZE8/vg3SIs8YS08ZtKMIC0SQOtAWgwIamHmKTfsOQfUwpNjZs1zIJ3H8ExiA34t7O3bHvwoq0uc33788W2eA9ZycscPH/6ITwsDMxqfh4GBEa+GUTAKRsEoGAVEAABhkUWw0WiQjQAAAABJRU5ErkJggg==","orcid":"","institution":"Sari Agricultural Sciences and Natural Resources University","correspondingAuthor":true,"prefix":"","firstName":"Raoufeh","middleName":"","lastName":"Abedini","suffix":""},{"id":514838369,"identity":"3c8c5e87-1625-4959-98e4-f8a52493d83f","order_by":1,"name":"Fatemeh Shahi","email":"","orcid":"","institution":"Sari Agricultural Sciences and Natural Resources University","correspondingAuthor":false,"prefix":"","firstName":"Fatemeh","middleName":"","lastName":"Shahi","suffix":""},{"id":514838370,"identity":"823f5095-e6ea-48a1-9231-1ca540979ef7","order_by":2,"name":"Maryam Ghorbani","email":"","orcid":"","institution":"Sari Agricultural Sciences and Natural Resources University","correspondingAuthor":false,"prefix":"","firstName":"Maryam","middleName":"","lastName":"Ghorbani","suffix":""},{"id":514838371,"identity":"a38d8448-f107-4d1a-9989-16bf5fc8f3eb","order_by":3,"name":"Seyed Mojtaba Amininasab","email":"","orcid":"","institution":"University of Kurdistan","correspondingAuthor":false,"prefix":"","firstName":"Seyed","middleName":"Mojtaba","lastName":"Amininasab","suffix":""}],"badges":[],"createdAt":"2025-08-16 11:38:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7387162/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7387162/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":91329997,"identity":"9b4d25bc-77c9-4f0e-a62a-e89c66d31b1e","added_by":"auto","created_at":"2025-09-15 10:46:20","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1033071,"visible":true,"origin":"","legend":"\u003cp\u003eTransverse and tangential surfaces of control specimens (a, b), and modified with: GA (c, d), 2% nanoclay/GA (e, f), GA/St (g, h), and 2% nanoclay/GA/St (i, j), respectively.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-7387162/v1/83942069267336bcea9892de.png"},{"id":91329994,"identity":"bd45d00a-f674-4252-9302-a58ca1f7e876","added_by":"auto","created_at":"2025-09-15 10:46:20","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":108823,"visible":true,"origin":"","legend":"\u003cp\u003eFTIR spectra of control © and modified specimens before (continuous lines) and after UV irradiation (dashed lines and asterisks).\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-7387162/v1/63805870b32ec0e1882d1c0b.png"},{"id":91331125,"identity":"15a1721e-bcdf-4e55-924f-34c26e80f37a","added_by":"auto","created_at":"2025-09-15 10:54:20","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":45190,"visible":true,"origin":"","legend":"\u003cp\u003eDensity and weight percent gain (WPG) for control and modified specimens (small and capital letters indicate Duncan grouping for density and WPG, respectively)\u003c/p\u003e","description":"","filename":"3.png","url":"https://assets-eu.researchsquare.com/files/rs-7387162/v1/601bd94850392caa935a3778.png"},{"id":91329995,"identity":"678a8600-94dd-4b3e-a8e9-5ace1fa08106","added_by":"auto","created_at":"2025-09-15 10:46:20","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":103339,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of modification on water absorption and swelling (letters on columns indicate Duncan grouping)\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-7387162/v1/2519de6965a323a602b0e920.png"},{"id":91332803,"identity":"b6011bc8-63d4-4ebf-8168-2c9cbba0c53c","added_by":"auto","created_at":"2025-09-15 11:19:58","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":44215,"visible":true,"origin":"","legend":"\u003cp\u003eContact angles of water droplet on wood surface\u003c/p\u003e","description":"","filename":"5.png","url":"https://assets-eu.researchsquare.com/files/rs-7387162/v1/5e826d52fc1375304b04ff1d.png"},{"id":91331330,"identity":"013946b4-8a6a-43e9-85bd-32ca2e94d006","added_by":"auto","created_at":"2025-09-15 11:02:20","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":14321,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of modification on hardness (letters on columns indicate Duncan grouping)\u003c/p\u003e","description":"","filename":"6.png","url":"https://assets-eu.researchsquare.com/files/rs-7387162/v1/613598c9a328b72e0c562f7a.png"},{"id":91330005,"identity":"6ca23b52-be53-49b3-b727-6b9451416770","added_by":"auto","created_at":"2025-09-15 10:46:20","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":51015,"visible":true,"origin":"","legend":"\u003cp\u003eEffect of modification on modulus of elasticity and modulus of rupture (letters on columns indicate Duncan grouping)\u003c/p\u003e","description":"","filename":"7.png","url":"https://assets-eu.researchsquare.com/files/rs-7387162/v1/6f5f8b10d120b4d5416cea66.png"},{"id":94490458,"identity":"bb345168-7213-4a48-aa0c-33700d861ee5","added_by":"auto","created_at":"2025-10-27 17:10:21","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2183728,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7387162/v1/43fdb477-e1c7-47e3-9d5b-6afed7d2a2db.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effects of surface modification with Glutaraldehyde/Nanoclay/Styrene on Poplar Wood Performance","fulltext":[{"header":"1 Introduction","content":"\u003cp\u003eWood is considered as an important building material for interior and exterior applications (Acosta et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2021\u003c/span\u003e), owing to its renewability, sustainability, easy processing, aesthetic appeal and high strength-to-weight ratio properties (Lopez-Gomez et al. \u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e2025\u003c/span\u003e; Sun et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2016\u003c/span\u003e). However, some inherent defects of light-fast growing species, such as susceptibility to dimensional changes at different relative humidity and low mechanical strength, restrict their industrial applications (Acosta et al. \u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e2021\u003c/span\u003e). Studies on enhancing wood properties by variety of methods can be summarized into four approaches: blocking hydroxyl groups of wood components, using low surface energy materials, improving wood surface roughness, and filling the wood cell cavities.\u003c/p\u003e\u003cp\u003eSurface modification by different techniques such as mechanical, thermal and chemical modification, can enhance the physical and mechanical properties of wood (Hill \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Petric \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). Chemical modification is an effective method for improving the dimensional stability, via crosslinking to the hydroxyl groups of wood components (Hill \u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e2006\u003c/span\u003e; Sun et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Che et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2019\u003c/span\u003e). Glutaraldehyde (GA) as an aldehyde, can improve the dimensional stability, durability, and hydrophobicity of wood by chemical modification through crosslinking to the wood structure (Sun et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2016\u003c/span\u003e; Xiao et al. \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e2012\u003c/span\u003e; Xie et al. \u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e2011\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eSince the porous structure of the GA modified wood is still empty, several studies have been conducted for introducing an efficient mechanism followed by cell wall modification such as: filling porosity with wax (Scholz et al. \u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e2012\u003c/span\u003e) and oil (Mohebby et al. \u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e2014\u003c/span\u003e), or in situ polymerization of monomers (Li et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Devi and Maji \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e). In situ polymerization, despite the retarding water absorption (Ermeydan et al. \u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e2014\u003c/span\u003e; Li et al. \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e2013\u003c/span\u003e) and enhancing some of mechanical properties, such as stiffness and flexural strength (Che et al. \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e2019\u003c/span\u003e; Sun et al. \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e2016\u003c/span\u003e), could not resistance expose weathering (Liu and Hu \u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e2021\u003c/span\u003e; Ermeydan et al. \u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e2020\u003c/span\u003e).\u003c/p\u003e\u003cp\u003eAccording to the literatures, for improving the wood resistance to weathering parameters such as UV, various nanoparticles including TiO2, ZnO, SiO2 and nano clay could be used (Marzi, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e2015\u003c/span\u003e; Devi and Maji \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e2013\u003c/span\u003e; Fufa et al. \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e2012\u003c/span\u003e). Nanoclay is a low cost, available, and safe nanoparticle, which improves stiffness, toughness, heat resistance, and flame resistance of wood composites (Frigione and Lettieri \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e2018\u003c/span\u003e). Accordingly, this research was conducted to develop a multifunctional surface modification by clay nanoparticles/ glutaraldehyde/styrene for enhancing the physicomechanical properties and photo stability of resultant product.\u003c/p\u003e"},{"header":"2 Material and Methods","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e\u003ch2\u003e2.1 Materials\u003c/h2\u003e\u003cp\u003eGlutaraldehyde 50% in aqueous solution and acetone were from Daejung (Seohaean- Siheung-si, Gyeonggi-do, Korea); Nano clay (Montmorillonite) and Benzoyl peroxide were purchased from Sigma-Aldrich and CDH (India), respectively. Styrene was prepared by Tabriz petrochemical co. (Iran); and Sodium acetate, Acetic acid and magnesium chloride were also produced by Kimia chemicals (Iran).\u003c/p\u003e\u003cp\u003ePoplar wood (\u003cem\u003ePopulus deltoeides\u003c/em\u003e) was harvested from a local forest in north of Iran, Sari. specimens were prepared from clear, defect free wood for physical, weathering and mechanical tests according to ASTM D4442-92 (2003), ASTM G154 (2006) and ASTM ASTM D143-14 (2014), respectively. In addition to control specimens, five replicate specimens were oven dried at 103\u0026thinsp;\u0026plusmn;\u0026thinsp;2\u0026deg;C and weighed for each of the modified woods. Experimental specimens were randomly separated according to Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003ecode of experimental treatments\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eTreatment\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eCode\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eC\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlutaraldehyde treated\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGA\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlutaraldehyde/ 1% nano clay\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGN1\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlutaraldehyde/ 2 nano clay\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGN2\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlutaraldehyde/Styrene\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGS\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlutaraldehyde/1% nano clay/Styrene\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGN1St\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGlutaraldehyde/2% nano clay/Styrene\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGN2St\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\u003ch2\u003e2.2 Methods\u003c/h2\u003e\u003cp\u003e50% GA solution was diluted to 20% solution by 0.1 molar sodium acetate buffer and acetic acid as a pH adjuster. Magnesium chloride was added to GA solution at 12.5 wt% as catalyst. For preparing the glutaraldehyde/nano clay (GA/NC) solution, 1 and 2 wt% nono clay was added to GA solution and was ultrasound in 30 minutes for preventing the NC sediment. Specimens were immersed in modifiers for 24 h, then removed from solution, wrapped in aluminums foils and heated at 120\u0026deg;C for 48 h.\u003c/p\u003e\u003cp\u003eAfter unwrapping, the modified specimens were dried for 24 h at 103\u0026deg;C. For GA/NC/styrene (St) modification, GA/NC modified specimens immersed in 20% St/acetone solution containing benzoyl peroxide 2wt% as initiator for 24 h, then wrapped in aluminum foil and heated at 90\u0026deg;C for 24 h to cure the styrene. Finally, the modified specimens were weighed, and the amount of weight percent gain (WPG) was evaluated according to Eq.\u0026nbsp;(1):\u003c/p\u003e\u003cp\u003eWeight gain\u0026thinsp;=\u0026thinsp;\u003cem\u003eW\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e \u0026ndash; \u003cem\u003eW\u003c/em\u003e\u003csub\u003e0\u003c/sub\u003e / \u003cem\u003eW\u003c/em\u003e\u003csub\u003e0\u003c/sub\u003e \u0026times; 100 (1)\u003c/p\u003e\u003cp\u003eWhere W\u003csub\u003e0\u003c/sub\u003e and W\u003csub\u003e1\u003c/sub\u003e are weight of specimens before and after modification (g).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e\u003ch2\u003e2.3 Characterization of modified wood\u003c/h2\u003e\u003cdiv id=\"Sec6\" class=\"Section3\"\u003e\u003ch2\u003e2.3.1 Fourier Transform Infrared Analysis\u003c/h2\u003e\u003cp\u003eFor evaluating the chemical structure, the FTIR Spectroscopy was conducted on the surface of control and modified specimens, before and after exposing UV radiation, using an Agilent cary630 FTIR spectrometer (Agilent Co., USA) in the attenuated total reflectance (ATR) mode. The resulting spectra were recorded in the range of 400 and 4000 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e with a resolution of 4 cm\u003csup\u003e\u0026minus;\u0026thinsp;1\u003c/sup\u003e.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec7\" class=\"Section3\"\u003e\u003ch2\u003e2.3.2 Morphological characterization\u003c/h2\u003e\u003cp\u003eMorphological features of untreated and treated specimens were examined using scanning electron microscope (SEM). Before applying the surface modification and coating, the transvers and tangential surfaces of the specimens were cut with a surgery blade to obtain smooth and fuzzy-free surfaces. After developing a hierarchical structure based on styrene coating on nanoparticles/glutaraldehyde modified wood, the specimen was mounted on the holder with a double-sided adhesive tape, gold sputter-coated and observed with an electron microscope (SNE-4500 M, Korea).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec8\" class=\"Section3\"\u003e\u003ch2\u003e2.3.3 Physical Properties\u003c/h2\u003e\u003cp\u003eThe physical properties of modified and control specimens were calculated by soaking them in deionized water during 168 h at room temperature. Water absorption (WA), water repellent efficiency (WRE), volumetric swelling (VS), and anti-swelling efficiency (ASE) were determined according to Eqs.\u0026nbsp;2 to 5:\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003e\u003cem\u003eWA\u003c/em\u003e\u0026thinsp;=\u0026thinsp;W\u003csub\u003e1\u003c/sub\u003e \u0026ndash; W\u003csub\u003e0\u003c/sub\u003e / W\u003csub\u003e0\u003c/sub\u003e \u0026times; 100 (2)\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003ewhere \u003cem\u003eW\u003c/em\u003e\u003csub\u003e0\u003c/sub\u003e and \u003cem\u003eW\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e are the weight of the specimens before and after soaking in water (g), respectively.\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003e\u003cem\u003eWRE\u003c/em\u003e\u0026thinsp;=\u0026thinsp;WA\u003csub\u003ec\u003c/sub\u003e \u0026ndash; WA\u003csub\u003e\u003cem\u003em\u003c/em\u003e\u003c/sub\u003e \u003cem\u003e/\u003c/em\u003e WA\u003csub\u003ec\u003c/sub\u003e \u0026times; 100 (3)\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003ewhere WA\u003csub\u003ec\u003c/sub\u003e and WA\u003csub\u003em\u003c/sub\u003e represent water absorption of control and modified specimens.\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003e\u003cem\u003eVS\u003c/em\u003e\u0026thinsp;=\u0026thinsp;\u003cem\u003eV\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e \u0026ndash; \u003cem\u003eV\u003c/em\u003e\u003csub\u003e\u003cem\u003e0\u003c/em\u003e\u003c/sub\u003e \u003cem\u003e/ V\u003c/em\u003e\u003csub\u003e0\u003c/sub\u003e \u0026times; 100 (4)\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003ewhere \u003cem\u003eV\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e and \u003cem\u003eV\u003c/em\u003e\u003csub\u003e0\u003c/sub\u003e are the volume after and before soaking in water (cm\u003csup\u003e3\u003c/sup\u003e).\u003cdiv class=\"BlockQuote\"\u003e\u003cp\u003e\u003cem\u003eASE\u003c/em\u003e\u0026thinsp;=\u0026thinsp;\u003cem\u003eS\u003c/em\u003e\u003csub\u003ec\u003c/sub\u003e \u0026ndash; \u003cem\u003eS\u003c/em\u003e\u003csub\u003e\u003cem\u003em\u003c/em\u003e\u003c/sub\u003e \u003cem\u003e/ S\u003c/em\u003e\u003csub\u003e1\u003c/sub\u003e \u0026times; 100 (5)\u003c/p\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003ewhere \u003cem\u003eS\u003c/em\u003e\u003csub\u003ec\u003c/sub\u003e is the volume swelling of control specimens (%), and \u003cem\u003eS\u003c/em\u003e\u003csub\u003em\u003c/sub\u003e is the volume swelling of the modified specimens (%).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec9\" class=\"Section3\"\u003e\u003ch2\u003e2.3.4 Accelerated weathering\u003c/h2\u003e\u003cp\u003eThe photostability of the specimens were evaluated by a chamber fabricated with S304 stainless steel internal walls. For simulating the harm of sunshine, Four UVA-340 W lamps (Philips F40T12/BL) with wavelength region from 365 nm to 295 nm and peak emission of 340 nm were used as light sources. The distance between each lamps, and lamp and specimens were 10 cm and 7 cm, respectively. This test was consisted of a continuous light irradiation for 300 hours on the specimen's surface.\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\n\u003ch3\u003e23.5 Color Measurement\u003c/h3\u003e\n\u003cp\u003eThe color of control and modified specimens, before and after weathering, was assessed using a ZB-A Colorimeter (Hangzhou Zhibang Automated Technology Co., China) in the CIELAB color system at three positions on the tangential surface of each specimen. This instrument provided the numerical values of L* (lightness intensity from zero: black to 100: white), a* (the color coordinate in pure green: -120 \u0026ndash;pure red: +120), b* (the color chroma on the pure yellow: +120 \u0026ndash;pure blue axis: -120). To compare the color changes after weathering, three factors, ΔL* as the lightness change, Δa* and Δb* as the color coordinates changes, and ΔE* as the overall color change were calculated using Eqs.\u0026nbsp;6\u0026ndash;9.\u003c/p\u003e\u003cp\u003eΔ\u003cem\u003eL\u003c/em\u003e\u0026thinsp;=\u0026thinsp;\u003cem\u003eL\u003c/em\u003e\u003csub\u003ef\u003c/sub\u003e \u0026ndash; \u003cem\u003eL\u003c/em\u003e\u003csub\u003ei\u003c/sub\u003e (6)\u003c/p\u003e\u003cp\u003eΔ\u003cem\u003ea\u003c/em\u003e\u0026thinsp;=\u0026thinsp;\u003cem\u003ea\u003c/em\u003e\u003csub\u003ef\u003c/sub\u003e \u0026ndash; \u003cem\u003ea\u003c/em\u003e\u003csub\u003ei\u003c/sub\u003e (7)\u003c/p\u003e\u003cp\u003eΔ\u003cem\u003eb\u003c/em\u003e\u0026thinsp;=\u0026thinsp;\u003cem\u003eb\u003c/em\u003e\u003csub\u003ef\u003c/sub\u003e \u0026ndash; \u003cem\u003eb\u003c/em\u003e\u003csub\u003ei\u003c/sub\u003e (8)\u003c/p\u003e\u003cp\u003eΔ\u003cem\u003eE\u003c/em\u003e = [Δ\u003cem\u003eL\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;Δ\u003cem\u003ea\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e\u0026thinsp;+\u0026thinsp;Δ\u003cem\u003eb\u003c/em\u003e\u003csup\u003e2\u003c/sup\u003e]\u003csup\u003e1/2\u003c/sup\u003e (9)\u003c/p\u003e\u003cp\u003ewhere the indexes of i and f introduce color changes before and after weathering.\u003c/p\u003e\u003cdiv id=\"Sec11\" class=\"Section3\"\u003e\u003cdiv class=\"Heading\"\u003e2.3.6 Surface roughness test\u003c/div\u003e\u003cp\u003eSurface roughness was measured perpendicular to grain of specimens using a Mahr Perthometer m3 instrument (G\u0026ouml;ttingen, Germany) with a tip radius of 2 \u0026micro;m and active tracing length of 17.5 mm. Each measurement was represented by the calculated roughness parameters R\u003csub\u003ea\u003c/sub\u003e (average roughness), R\u003csub\u003ez\u003c/sub\u003e (roughness depth: mean height of 10 point from profile), and R\u003csub\u003emax\u003c/sub\u003e (maximum roughness). Three tracing were made on each measuring surface.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec12\" class=\"Section3\"\u003e\u003cdiv class=\"Heading\"\u003e2.3.7 Wettability\u003c/div\u003e\u003cp\u003eWater contact angles (WCAs) on the surface of control and modified specimens were measured to evaluate the effect of modification on the wettability. Images of water droplets (about 4 \u0026micro;l) on the specimen\u0026rsquo;s surface, were captured at intervals of 10s for a total duration of 120s, using a digital microscope (Dino-lite AM7915MZTL, Taiwan) that was connected to a computer supported by Dinocapture 2.0 version 1.5.36 software. For every type of modifications, three specimens were tested, and WCA was determined on three spots of tangential surface of each specimen. Finally, images were analyzed by ImageJ software to determine contact angle.\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec13\" class=\"Section3\"\u003e\u003cdiv class=\"Heading\"\u003e2.3.8 Mechanical Properties\u003c/div\u003e\u003cp\u003eMechanical properties, including bending properties (strength (MOR) and modulus (MOE)) and hardness were tested according to ASTM D143-14 (2014), using a SANTAM STM-20 machine (Santam Co., Iran).\u003c/p\u003e\u003c/div\u003e\u003cdiv id=\"Sec14\" class=\"Section2\"\u003e\u003ch2\u003e2.4 Statistical Analysis\u003c/h2\u003e\u003cp\u003eA complete randomized design and Duncan grouping were used to evaluate the effect of different surface modifications on the properties of poplar wood. Statistical analysis was conducted using SPSS software program, version 17.0 (IBM Corp., Armonk, NY, USA).\u003c/p\u003e\u003c/div\u003e"},{"header":"3 Results and discussion","content":"\u003cp\u003e\u003cstrong\u003e3.1 Morphology\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFig. 1 shows the scanning electron micrographs of the control and modified specimens. Transverse and tangential surfaces of the control specimens are respectively, presented in Figure 1(a) and (b), in which vessel and fiber lumens are completely empty and inter-vessel pits are open. The porous structure of the glutaraldehyde-modified wood was maintained (Sun et al. 2016) (Fig. 1(c)), but in contrast with control, reducing the aperture of inter-vessel pits in the tangential surface confirm the bulking of the cell walls (Figure 1(d)). It confirms that the majority of the glutaraldehyde molecules reacted with the cell wall polymers and resulted in cell wall bulking. Deposition of nanoparticles in fibers (Fig. 1(e)) and internal wall of the vessel (Fig. 1(f)) are evident. 20% Styrene solution polymerized as a layer on the inner surface of the fibers and the vessels (Fig. 1h). The layers formed by styrene on the clay nanoparticles/glutaraldehyde modified structure, covered the pits of the cell walls (Fig. 1i \u0026amp; j).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.2 Surface chemistry\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFig. 2 illustrates the infrared spectra of all specimens before and after UV irradiation. The band at 3350 cm\u003csup\u003e-1\u003c/sup\u003e attributed to the hydroxyl groups of alcohol, phenol, and acids (Sun et al. 2016; Xing et al. 2015), significantly reduced for GN1St and GN2St specimens due to the reaction of free \u0026minus;OH groups with GA\u0026rsquo;s aldehyde groups and forming covalent bonds. The peak within the range of 2780 to 3000 cm\u003csup\u003e-1\u0026nbsp;\u003c/sup\u003eis associated to the C-H stretching in the styrene polymer and methyl/methylene groups of the wood. The peak at 1735 cm⁻\u0026sup1; assigned to C=O stretching in esters, aldehydes, and ketones (Sun et al. 2016; Xing et al. 2015), shifts to 1717 cm⁻\u0026sup1; in glutaraldehyde-modified\u0026nbsp;specimens\u0026nbsp;subsequent to ketone formation (R\u0026ndash;CO\u0026ndash;R). Enhancing the intensity of this peak for glutaraldehyde/styrene\u0026nbsp;specimens\u0026nbsp;indicates a greater contribution from carbonyl groups\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e(Devi and Maji, 2013). 1418 cm\u003csup\u003e-1\u003c/sup\u003e peak related to the nanoclay carbonate content intensified with nanoparticle loading. In glutaraldehyde-treated wood, OH bending vibrations of cellulose/hemicellulose at 1317 cm\u003csup\u003e-1\u003c/sup\u003e, diminished due to \u0026ndash;OH reaction with aldehydes. 1230 cm\u003csup\u003e-1\u003c/sup\u003e peak related to the formation of methylene ether bridges (-RCH-O-CHR-) (Xi et al. 2018) reduced in GN1 and GA treatments. Peaks at 1030\u0026ndash;1050 cm\u003csup\u003e-1\u003c/sup\u003e (aliphatic alcohols/ethers) and 1160 cm\u003csup\u003e-1\u003c/sup\u003e (C\u0026ndash;O\u0026ndash;C stretching) confirmed the reaction of hydroxyl groups of wood with glutaraldehyde via formation of acetal bonds (Sun et al. 2016). The montmorillonite consists of approximately 43% SiO2, 16% AL2O3, and other elements such as Fe2O3 and MgO (Komatsu et al. 2016). In all nanoparticle-treated specimens, peaks in the range of 1870 cm\u003csup\u003e-1\u003c/sup\u003e and 770 cm\u003csup\u003e-1\u003c/sup\u003e confirmed the presence of clay nanoparticles in the modified wood substrate (Devi and Maji, 2013).\u003c/p\u003e\n\u003cp\u003eAfter 300 hours of UV irradiation, the combined nano clay/glutaraldehyde (GA) modification significantly improved photostability, as demonstrated by the stability observed in the FTIR spectra of modified specimens. The hydroxyl group vibrations (3400 cm\u003csup\u003e-1\u003c/sup\u003e region) exhibited negligible changes upon UV irradiation. The intensity of the C-H stretching vibration of methylene groups (2933 cm\u003csup\u003e-1\u003c/sup\u003e) decreased in all specimens upon UV irradiation, consistent with previous findings (Nguyen et al. 2016). The carbonyl stretching vibration peak at 1731 cm\u003csup\u003e-1\u003c/sup\u003e increased significantly in the control specimens, whereas the modified specimens showed negligible changes in this spectral region. This phenomenon results from photooxidative degradation, wherein UV irradiation breaks down the lignin and cellulose polymer chains, and subsequently increased the carbonyl index (Devi and Maji 2013; Teacă et al. 2013). According to the literatures, clay nanoparticles as UV stabilizers, in combination with vinyl polymers, effectively reduced the carbonyl index intensity and inhibited photodegradation (Devi and Maji 2013). The intensity of lignin\u0026apos;s aromatic vibrations at 1607 cm\u003csup\u003e-1\u003c/sup\u003e and 1506 cm\u003csup\u003e-1\u003c/sup\u003e decreased significantly in control specimens, indicating their susceptibility to photodegradation (Teacă et al. 2013). Glutaraldehyde (GA) modification, likely through the chemical blocking of reactive phenolic groups, protected lignin against degradation (Xiao et al. 2012).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.3 Color changes\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTable 2 shows the color index of control and modified specimens before and after UV irradiation. The modification induced darkening on all specimens relative to the controls, and the GN2St combined modification exhibited the most pronounced effect, which quantitatively confirmed by the significant reduction in the L* index values. Darkening effect of styrene has previously reported for pine wood (Acosta et al. 2021). The modification resulted in a significant increase in a* (yellowness) and b* (redness) index. Unlike the modified specimens, weathering significantly changed color of the control specimen, with increasing a* and the b* indexes from 6.35 to 12 and 34.47 to 62.32, respectively. With the exception of the control specimen, weathering significantly increased the L* index (lightness) in all modified specimens. Degradation of cell wall polymers in the control specimens was identified as a key factor contributing to their color darkening (Ermeydan et al. 2020).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e∆E* value represents the overall change of surface color, resulting from changes in all color indexes. The control specimens exhibited the most pronounced total color change following UV irradiation, primarily due to lignin\u0026apos;s strong UV absorption capacity and subsequent degradation of its chromophoric groups (Che et al., 2019; Xiao et al. 2012). Modification with glutaraldehyde, particularly in the presence of 1% clay nanoparticles, mitigated these alterations. Xiao and the coworkers\u0026nbsp;also reported a reduction in lignin and hemicellulose degradation of GA-modified wood following weathering (Xiao et al. 2012). The enhanced photostability of lignin in GA-modified wood was attributed to the blocking of lignin\u0026apos;s phenolic groups by glutaraldehyde (Xiao et al. 2012). Modification with styrene, with the exception of GN1St, resulted in more pronounced surface color changes.\u0026nbsp;According to literatures, polystyrene rapidly undergoes a yellowing reaction exposed to UV light (Ermeydan et al. 2020). The specimens modified with clay nanoparticles at a concentration of 1% (GN1St and GN1) exhibited the least color change after weathering. However, increasing the concentration of nanoclay to 2% resulted in a higher color change, likely attributable to agglomeration of clay nanoparticles. Fufa and coworkers similarly demonstrated that the nanoparticles markedly diminished color changes of weathered specimens (Fufa et al. 2012). Previous studies have demonstrated that the nanoclay and nanotitanium, at 0.5% concentration improved wood\u0026apos;s photostability more effectively than higher concentrations (Devi and Maji 2013).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 2\u0026nbsp;\u003c/strong\u003eColor parameters after UV irradiation\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cdiv align=\"\"\u003e\n \u003ctable border=\"1\" cellspacing=\"0\" cellpadding=\"0\" width=\"557\"\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003e\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"3\" valign=\"top\" style=\"width: 227px;\"\u003e\n \u003cp\u003eBefore irradiation\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd colspan=\"4\" valign=\"top\" style=\"width: 274px;\"\u003e\n \u003cp\u003eAfter irradiation\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eSample code\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003eL*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003ea*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003eb*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003eL*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003ea*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003eb*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e∆E*\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eC\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e66.53 (0.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e6.35 (0.49)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e34.47 (0.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e60.72 (0.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e12.02 (0.41)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e62.32\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.7)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e29.02\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eG\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e57.41 (0.27)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e17.99 (0.99)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e59.62 (0.08)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e60.20 (0.45)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e18.16\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e61.55 (0.49)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e3.43\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eGN1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e61.63 (0.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e17.02 (0.87)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e61.09 (0.76)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e64.55 (0.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e16.44\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.3)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e61.89\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e3.24\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eGN2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e59.57 (0.24)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e16.81 (0.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e59.83 (0.59)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e63.78 (0.32)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e16.50 (0.11)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e62.33\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(0.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e4.93\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eGS\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e55.11 (0.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e21.98 (0.45)\u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e60.51 (0.23)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e60.68 (0.33)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e19.79 (0.25)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e62.51\u003c/p\u003e\n \u003cp\u003e\u0026nbsp;(1.4)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e6.39\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eGN1St\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e60.68 (0.21)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e15.70 (0.19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e60.57 (0.39)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e63.28 (0.18)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e15.59 (0.15)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e58.85 (1.03)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e3.28\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd valign=\"top\" style=\"width: 56px;\"\u003e\n \u003cp\u003eGN2St\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e51.23 (0.37)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e21.83 (0.55)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e58.33 (0.34)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e57.81\u003c/p\u003e\n \u003cp\u003e(0.6)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e19.07 (0.13)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 76px;\"\u003e\n \u003cp\u003e59.06 (2.19)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd valign=\"top\" style=\"width: 47px;\"\u003e\n \u003cp\u003e7.47\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"8\" valign=\"top\" style=\"width: 557px;\"\u003e\n \u003cp\u003eNote: The data in parenthesis refers to the standard deviations \u0026nbsp;\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n\u003c/div\u003e\n\u003cp\u003e\u003cstrong\u003e3.4 Physical properties\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eFigures 3\u0026ndash;5 present the physical property results of the control and modified specimens. The bulking coefficient of the GA-modified specimen (6.1%), which is the only chemical reactive with the wood in this study, confirmed the penetration of polar GA into the wood cell walls, without applying pressure. A significant difference was observed \u003cem\u003ein\u003c/em\u003e the weight percent gain (WPG) between specimens modified with GA and those modified with GA/styrene (fig. 3), which increased by nanoparticles. The highest total weight percent gain was calculated for GN1St and GN2St. However, WPG of styrene decreased with \u003cem\u003ehigher\u003c/em\u003e nanoparticle concentration, probably due to nanoparticles agglomeration, which may physically block the pathways of styrene penetration.\u003c/p\u003e\n\u003cp\u003eWater absorption and swelling analyses demonstrated that GA modification effectively enhanced both hydrophobicity and dimensional stability. According to the results of water absorption and swelling, glutaraldehyde modification improved both\u003cem\u003e\u0026nbsp;\u003c/em\u003ehydrophobicity and dimensional stability of the resulting product, without significant enhancement with addition of nanoclay (Fig. 4a\u0026amp;b). Impregnation with styrene significantly reduced water absorption and dimensional changes for all specimens and the lowest water absorption was measured for GS modified specimens (Fig. 4a). Glutaraldehyde, as a dialdehyde, reacts with one and two hydroxyl groups of wood to form hemiacetal and acetal, respectively. Under hydrolytic conditions, the acetal demonstrates significantly greater stability compared to the hemiacetal (Xie et al. 2011). The combination of hydroxyl groups blocking and cell wall bulking by glutaraldehyde, accompanied with porosity reduction via styrene polymerization reduced the water absorption (Ermeydan et al. 2020; Che et al. 2019; Sun et al. 2016; Ermeydan et al. 2014).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.5 Roughness\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSurface roughness plays a critical role in coating adhesion to wood substrate (Hang et al. 2024). According to the results, the effect of modification on surface roughness was statically significant (Table 3). The highest roughness was observed in the GN1 and GN1St specimens, whereas the lowest was recorded for the control ones. Glutaraldehyde modification significantly increased surface roughness, although this effect has not been previously reported in the literature. The roughness parameters increased significantly in specimens containing 1% nano clay, but decreased with increasing nanoparticle concentration to 2%. Probably, the higher concentration of nanoparticles promoted more uniform surfaces by filling the pores, thereby reducing surface roughness. The addition of styrene had no significant effect on surface roughness of GA modified specimens.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eTable 3\u0026nbsp;\u003c/strong\u003eSurface roughness parameters of untreated and modified specimens\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e\u003cimg 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\" width=\"746\" height=\"289\"\u003e\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.6 Wettability\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eContact angle measurements revealed a significant reduction in wettability for the modified specimens\u0026nbsp;(Fig. 5).\u0026nbsp;In contrast to the GN1St specimens, which exhibited the highest contact angles, the control specimens showed the lowest contact angle values.\u003c/p\u003e\n\u003cp\u003eWood modification with glutaraldehyde increased the contact angle by reducing hydroxyl groups and porosity, followed by the bulking of the wood cell wall. The addition of nano clay into the glutaraldehyde enhanced the water contact angle on the modified specimens, which could be attributed to the increase in surface roughness. The GN2 specimen exhibited an initial contact angle of 125\u0026deg;, which underwent rapid reduction, ultimately reaching the lowest value among all modified samples within 120 seconds. This rapid reduction could be attributed to the reduction in surface roughness caused by nanoparticle agglomeration. Combining chemical modification/nanoparticles with styrene demonstrated both higher and more stable contact angles, suggesting the polymeric matrix effectively immobilized the nanoparticles and blocked the path of water penetration (Acosta et al. 2021).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003e3.6 Mechanical properties\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eIn this study, the effect of modification on some mechanical properties including hardness and bending was measured. Material resistance to local and bulk deformation is represented by hardness and the modulus of elasticity, respectively (Yadav and Yusoh 2019).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eSurface modification with GA increased the hardness (Fig. 6). This increment could be attributed to the crosslinking of microfibrils with glutaraldehyde, resulting in enhanced cell wall hardness\u0026nbsp;(Xiao et al. 2010). Adding nanoparticles and styrene did not create a significant increase in hardness compared to GA modified specimens. However, elevated nanoparticle concentration, with or without styrene, reduced hardness to the extent that no statistically significant difference remained between the modified surface and the control specimen (Yadav and Yusoh 2019).\u003c/p\u003e\n\u003cp\u003eGA modification significantly reduced the modulus of rupture (MOR) while having no statistically significant effect on the modulus of elasticity (MOE) (Fig.7 a\u0026amp;b). These findings align with earlier studies on scot pine GA modified wood (Lopez-Gomez et al. 2025; Sun et al. 2016). Compared to control specimens, GA/nanoclay modification enhanced the modulus of elasticity (MOE) (GN1 and GN2). The addition of styrene enhanced the MOE of the GA modified specimens, whereas this property decreased in the GA/nanoclay modified ones. Consistent with our findings, Che and coworkers documented that styrene incorporation increased the modulus of elasticity (MOE) through its reinforcing role within wood cell cavities (Che et al. 2019). Yadav and Yusoh (2019) reported an increase in the elastic modulus at 1% nanoclay loading, while a followed by a progressive decrease at higher concentrations up to 2.5%.\u003c/p\u003e\n\u003cp\u003eUnlike MOE, MOR decreased after modification, with no significant differences observed among the different groups. The reduction in MOR following GA modification can be attributed to the restricted mobility of wood cell wall polymers caused by GA crosslinking within the cell wall (Xiao et al. 2010; Sun et al. 2016). The GA/styrene modification enhanced wood stiffness. Because MOR is more sensitive to stiffness changes than MOE (Sun et al. 2016), the GA/styrene ultimately reduced the flexural strength of the final product.\u0026nbsp;\u003c/p\u003e"},{"header":"4 Conclusion","content":"\u003cp\u003e\u003cul\u003e\u003cli\u003e\u003cp\u003eScanning electron micrographs confirmed the cell wall bulking following GA modification, along with styrene coating on the inner surface of the fibers. Clay nanoparticles penetrated the pit membrane, however, their penetration and overall effectiveness decreased at higher concentration due to increased agglomeration tendency.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eAccording to the FTIR spectra, nanoclay/GA increased the photostability of the modified specimens. While glutaraldehyde limited lignin degradation, styrene-modified specimens exhibited rapid yellowing upon UV exposure, and requires additional protective for outdoor applications.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eGA/styrene reduced water absorption and dimensional changes. Although styrene did not form direct bonds with the cell wall, its penetration into the nonpolar cell wall components following GA modification improved the anti-swelling efficiency.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eSurface modification with glutaraldehyde/1% nanoclay/styrene increased the water contact angle and reduced surface wettability through enhanced surface roughness.\u003c/p\u003e\u003c/li\u003e\u003cli\u003e\u003cp\u003eSurface modification with GA increased the hardness, but the nanoparticles and styrene showed no statistically significant enhancement in the hardness of GA-modified specimens. While GA/nanoclay enhanced MOE, subsequent styrene addition further increased MOE in GA-modified specimens, but reduced it in GA/nanoclay-modified samples. Following modification, MOR exhibited a decrease, with no statistically significant differences between treatment groups. It is suggested that the effects of pressure processes be investigated to substantially enhance this resistance.\u003c/p\u003e\u003c/li\u003e\u003c/ul\u003e\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor contributions\u003c/strong\u003e Raoufeh Abdini planned and supervised the project, performed the data analyses, and writing the manuscript. Fatemeh Shahi produced the test specimens and carried out the experiments. Maryam Ghorbani designed, conceived the original idea, advised the project and reviewed and edit the manuscript. Seyed Mojtaba Amininasab planned and advised the project.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u0026nbsp;\u003c/strong\u003eThe authors did not receive support from any organization for the submitted work.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eData availability\u003c/strong\u003e No datasets were generated or analysed during the current study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConflict of interest\u003c/strong\u003e The authors declare no competing interests.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eAcosta AP, Delucis AR, Amico SC, Gatto DA (2021) Fast-growing pine wood modified by a two-step treatment based on heating and in situ polymerization of polystyrene. Construction and Building Materials 302: 1-11. https://doi.org/10.1016/j.conbuildmat.2021.124422\u003c/li\u003e\n\u003cli\u003eAmerican Society for Testing and Materials (2014) ASTM D143: Standard test methods for small clear specimens of timber. \u003cem\u003eASTM International\u003c/em\u003e, West Conshohocken, PA, USA.\u003c/li\u003e\n\u003cli\u003eAmerican Society for Testing and Materials (2006) ASTM G154: Standard practice for operating fluorescent light apparatus for UV exposure of nonmetallic materials. \u003cem\u003eASTM International\u003c/em\u003e, West Conshohocken, PA, USA. \u003c/li\u003e\n\u003cli\u003eAmerican Society for Testing and Materials (2003) ASTM D4442: Standard test methods for direct moisture content measurement of wood and wood-base materials. \u003cem\u003eASTM International\u003c/em\u003e, West Conshohocken, PA, USA.\u003c/li\u003e\n\u003cli\u003eChang TC, Chang HT, Wu CL, Lin HY, Chang ST (2010) Stabilizing effect of extractives on the photooxidation of Acacia confusa wood. Polym Degrad Stab 95:1518-1522. https://doi.org/10.1016/j.polymdegradstab.2010.06.012\u003c/li\u003e\n\u003cli\u003eChe W, Xiao Z, Wang Z, Nguyen TT, Xie Y (2019) Enhanced weathering resistance of radiata pine wood by treatment with an aqueous styrene/acrylic acid copolymer dispersion. Journal of Wood Chemistry and Technology 39:1-15. https://doi.org/10.1080/02773813.2019.1636824\u003c/li\u003e\n\u003cli\u003eDevi RR, Maji TK (2013) In situ polymerized wood polymer composite: effect of additives and nanoclay on the thermal and mechanical properties. Materials Research 16:954-963. https://doi.org/10.1590/S1516-14392013005000071\u003c/li\u003e\n\u003cli\u003eErmeydan MA, Babacan M, Tomak ED (2020) Evaluation of dimensional stability, weathering and decay resistance of modified pine wood by in-situ polymerization of styrene. Journal of Wood Chemistry and Technology 40(5):1-12. https://doi.org/10.1080/02773813.2020.1786127\u003c/li\u003e\n\u003cli\u003eErmeydan MA, Cabane E, Gierlinger N, Koetz J, Burgert I (2014) Improvement of wood material properties via in situ polymerization of styrene into tosylated cell walls. Royal Society of Chemistry 4:12981-12988. https://doi.org/10.1039/c4ra00741g\u003c/li\u003e\n\u003cli\u003eFrigione M, Lettieri M (2018) Novel attribute of organic-inorganic hybrid coatings for protection and preservation of materials (stone and wood) belonging to cultural heritage. Coatings 8(9):319. https://doi.org/10.3390/coatings8090319\u003c/li\u003e\n\u003cli\u003eFufa SM, Jelle BP, Hovde PJ, Rorvik PM (2012) Coated wooden cladding and the influence of nanoparticles on the weathering performance. Progress in Organic Coatings 75:72-78. https://doi.org/10.1016/j.porgcoat.2012.03.010\u003c/li\u003e\n\u003cli\u003eHang J, Yan X, Li J (2024) A review on the effect of wood surface modification on paint film adhesion properties. Coatings 14(10):1313. https://doi.org/10.3390/coatings14101313\u003c/li\u003e\n\u003cli\u003eHill CAS (2006) Wood Modification Chemical, Thermal and other Processes. John Wiley \u0026amp; Sons, Hoboken. https://doi.org/10.1002/0470021748\u003c/li\u003e\n\u003cli\u003eKomatsu LGH, Oliani WL, Lugao AB, Parra DF (2016) Nanocomposites of irradiated polypropylene with clay are degradable? Radiation Physics and Chemistry 118:11-15. https://doi.org/10.1016/j.radphyschem.2015.06.004\u003c/li\u003e\n\u003cli\u003eLi Y, Dong X, Lu Z, Jia W, Liu Y (2013) Effect of polymer in situ synthesized from methyl methacrylate and styrene on the morphology, thermal behavior and durability of wood. Journal of Applied Polymer Science 128(1): 13-20. https://doi.org/10.1002/app.38099\u003c/li\u003e\n\u003cli\u003eLiu Y, Hu J (2021) Investigation of polystyrene-based microspheres from different copolymers and their structural color coatings on wood surface. Coatings 11:14. https://doi.org/10.3390/coatings11010014\u003c/li\u003e\n\u003cli\u003eLopez-Gomez YM, Nissinen VH, Barbero-Lopez A, Venalainen M, Haapala A (2025) Assessment of glutaraldehyde and formaldehyde for enhancing decay resistance and reducing caffeine leachability in Scots pine wood. International Biodeterioration \u0026amp; Biodegradation 198: 0964-8305. https://doi.org/10.1016/j.ibiod.2025.106014\u003c/li\u003e\n\u003cli\u003eMarzi T (2015) Nanostructured materials for protection and reinforcement of timber structures: a review and future challenges. Construction and Building Materials 97:119-130. https://doi.org/10.1016/j.conbuildmat.2015.07.016\u003c/li\u003e\n\u003cli\u003eMohebby B, Kevily H, Kazemi-Najafi S (2014) Oleothermal modification of fir wood with a combination of soybean oil and maleic anhydride and its effects on physico-mechanical properties of treated wood. Wood Science and Technology 48:797-809. https://doi.org/10.1007/s00226-014-0640-5\u003c/li\u003e\n\u003cli\u003eNguyen TV, Nguyen TA, Dao PH, Mac VP, Nguyen AH, Do MT, Nguyen TH (2016) Effect of rutile titania dioxide nanoparticles on the mechanical property, thermal stability, weathering resistance and antibacterial property of styrene acrylic polyurethane coating. Advances in Natural Sciences: Nanoscience and Nanotechnology 7:045015. https://doi.org/10.1088/2043-6262/7/4/045015\u003c/li\u003e\n\u003cli\u003ePetric M (2013) Surface modification of wood: A critical review. Reviews of Adhesion and Adhesives 1(2): 216-247. https://doi: 10.7569/RAA.2013.097308\u003c/li\u003e\n\u003cli\u003eSchneider MH, Phillips JG, Lande S (2000) Physical and mechanical properties of wood polymer composites. Journal of Forest Engineering 11:83-89. https://doi.org/10.1080/08435243.2000.10702748\u003c/li\u003e\n\u003cli\u003eScholz G, Krause A, Militz H (2012) Full impregnation of modified wood with wax. European Journal of Wood and Wood Products 70:91-98. https://doi.org/10.1515/hf-2016-0063\u003c/li\u003e\n\u003cli\u003eSun W, Shen H, Cao J (2016) Modification of wood by glutaraldehyde and poly (vinyl alcohol). Materials \u0026amp; Design 96: 392-400. https://doi.org/10.1016/j.matdes.2016.02.044\u003c/li\u003e\n\u003cli\u003eTeacă CA, Roşu D, Bod\u0026icirc;rlău R, Roşu L (2013) Structural changes in wood under artificial UV light irradiation determined by FTIR spectroscopy and color measurements - A brief review. BioResources 8(1):1478-1507. https://doi.org/10.15376/biores.8.1.1478-1507\u003c/li\u003e\n\u003cli\u003eXiao Z, Xie Y, Mai C (2012) The fungal resistance of wood modified with glutaraldehyde. Holzforschung 66:237-243. https://doi.org/10.1515/HF.2011.138\u003c/li\u003e\n\u003cli\u003eXiao Z, Xie Y, Militz H, Mai C (2010) Effects of chemical modification with glutaraldehyde on the mechanical properties of wood. Holzforschung 64:475-482. https://doi.org/10.1515/HF.2010.058\u003c/li\u003e\n\u003cli\u003eXi X, Pizzi A, Amirou S (2018) Melamine-glyoxal-glutaraldehyde wood panel adhesives without formaldehyde. Polymers 10(1):1-18. https://doi.org/10.3390/polym10010022\u003c/li\u003e\n\u003cli\u003eXie Y, Hill CAS, Xiao Z, Mai C, Militz H (2011) Dynamic water vapour sorption properties of wood treated with glutaraldehyde. Wood Science and Technology 45:49-61. https://doi.org/10.1007/s00226-010-0311-0\u003c/li\u003e\n\u003cli\u003eXing D, Wang S, Li J (2015) Effect of artificial weathering on the properties of industrial-scale thermally modified wood. BioResources 10(4):8238-8252. https://doi.org/10.15376/biores.10.4.8238-8252\u003c/li\u003e\n\u003cli\u003eYadav SM, Yusoh KB (2019) Subsurface mechanical properties and subsurface creep behavior of modified nanoclay-based wood-plastic composites studied by nanoindentation. Polymer Bulletin 76(1):2179-2196. https://doi.org/10.1007/s00289-018-2497-5\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"poplar wood, surface chemical modification, glutaraldhyde, chemo/physico/mechanical properties, weathering resistance","lastPublishedDoi":"10.21203/rs.3.rs-7387162/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7387162/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eLimited application of fast-growing species due to dimensional changes and low mechanical strength can be expand by modification methods. In this study, the effect of surface modification with aldehydes/nanoparticles/polymer on chemo/physico/mechanical properties of poplar (\u003cem\u003ePopulus Spp\u003c/em\u003e.) wood was investigated. For this purpose, specimens were modified with 20% Glutaraldehyde (GA) solution, without and with nano clay (NC) (in 1% and 2%), and subsequently with styrene (St) for combined modification. According to Fourier-transform infrared (FTIR) spectroscopy results, changes of chemical structure confirmed the reaction of GA with wood. Scanning electron microscopy (SEM) images showed reducing of vessels pit aperture size by GA modification and forming a layer of St on the internal surface of lumens, which resulted in less hygroscopicity for modified specimens. The highest dimensional stability was calculated for GA/St and GA/NC/St modified specimens. GA modification enhanced the photostability of wood exposed to accelerated weathering, and this feature was intensified with adding NC. GA modification increased surface roughness and subsequently contact angle of specimens, which was more obvious by adding NC. GA significantly improved the hardness of specimens, and the highest modulus of bending was measured for GA/St modified wood. Finally, it could be concluded that GA/NC/styrene modification is a promising method for enhancing dimensional stability and weathering resistance of poplar wood, but for efficient strengthening of GA modified wood, styrene impregnation under pressure is suggested.\u003c/p\u003e","manuscriptTitle":"Effects of surface modification with Glutaraldehyde/Nanoclay/Styrene on Poplar Wood Performance","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-09-15 10:46:15","doi":"10.21203/rs.3.rs-7387162/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c578a9bd-c823-4e58-ad53-85b05c6a92f3","owner":[],"postedDate":"September 15th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-10-27T16:48:35+00:00","versionOfRecord":[],"versionCreatedAt":"2025-09-15 10:46:15","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7387162","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7387162","identity":"rs-7387162","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}