H₂O as an efficient green initiator to construct renewable hydrophobic porous materials for pollutant removal

Abstract

The utilization of H₂O as solvent is widely favored in the field of material synthesis due to its environmentally friendly properties. However, in the synthesis process of renewable hydrophobic materials, the limited solubility of containing hydroxyl carbohydrate in H₂O poses challenges to achieving effective collisions. Herein, H₂O-assisted grinding facilitated the generation of active hydroxyl groups in sodium methylsilicate, thereby promoting condensation or encapsulation with diversified substrates (e.g., molecules, lignin, cellulose, fulvic acid, plants, hydroxide, metal salts, elementary substance, oxides, and metal-organic framework-5 (MOF-5)) through node-node, node-line, node-sheet connections and surface-modified strategies. The reactions were catalyzed exclusively by H₂O and accompanied by the CO₂ fixation. The first utilization of sodium methylsilicate enabled the successful fabrication of organic/plant/metal-based hydrophobic porous materials and silicon-modified materials from renewable and cost-effective substrates through mechanical activation. H₂O-assisted grinding enabled the prepared hydrophobic porous materials with surface areas of 129–388 m²/g and yields of 66%–90%, overcoming challenges in liquid-phase methods. Notably, H₂O in the untreated plant tissues can initiate the system to directly synthesize renewable hydrophobic porous materials and capture CO₂ from the atmosphere to produce NaHCO₃ as the byproduct. Meanwhile, the obtained hydrophobic material has been successfully applied in oil-water separation (permeability of petroleum ether > 801 L/(m²·h)), medical waste adsorption (propofol separation rate > 85%), pollutant degradation (Rhodamine B, Congo red, and Nile red dye removal rate of 90%–99.99%), and flood control engineering (remained well waterproof after 10 days). The work proposed a general and facile H₂O-assisted grinding strategy to prepare various renewable hydrophobic materials, enabling efficient utilization of naturally abundant hydroxyl-containing renewable resources and demonstrating promising potential for environmental applications.

Keywords

Hydrophobic material / Renewable resource / Sodium methylsilicate / Pollutant removal / Mechanochemistry

References

[1] Abbas, H., Alawi, R., Hussin, M.H., Johari, Y., Muttlib, N.A.A., Karobari, M.I., 2023. Characterization of reinforced nanohybrid dental composite resin made of nano silica rice husk with the reinforcement utilizing kenaf fiber. Cellulose 30, 9693-9708.

[2] Ben Amara, F., Dionne, E.R., Kassir, S., Pellerin, C., Badia, A., 2020. Molecular origin of the odd-even effect of macroscopic properties of n-alkanethiolate self-assembled monolayers: bulk or interface? J. Am. Chem. Soc. 142, 13051-13061.

[3] Belenguer, A.M., Lampronti, G.I., de Mitri, N., Driver, M., Hunter, C.A., Sanders, J.K.M., 2018. Understanding the influence of surface solvation and structure on polymorph stability: a combined mechanochemical and theoretical approach. J. Am. Chem. Soc. 140, 17051-17059.

[4] Bellinetto, E., Regoli, S., Barni, R., Canevali, C., Boumezgane, O., Zoia, L., Riccardi, C., Turri, S., Griffini, G., 2025. Enhanced performance and reprocessability in polypropylene-lignin blends through plasma treatment. J. Bioresour. Bioprod. 10, 170-186.

[5] Cao, X.Y., Guo, X., Xiao, T.Y., Jia, W.C., Liu, X.D., Li, C.G., Zhang, H., Fatehi, P., Shi, H.Q., 2025. Superhydrophobic biomass-based aerogel fabricated in lithium bromide trihydrate for oil adsorption. Sep. Purif. Technol. 354, 129421.

[6] Castro-Aguirre, E., Iñiguez-Franco, F., Samsudin, H., Fang, X., Auras, R., 2016. Poly(lactic acid)-mass production, processing, industrial applications, and end of life. Adv. Drug Deliv. Rev. 107, 333-366.

[7] Chen, L., Yu, L., Qi, L.H., Eichhorn, S.J., Isogai, A., Lizundia, E., Zhu, J.Y., Chen, C.J., 2025. Cellulose nanocomposites by supramolecular chemistry engineering. Nat. Rev. Mater. 10, 728-749.

[8] Chowdhury, M.R., Steffes, J., Huey, B.D., McCutcheon, J.R., 2018. 3D printed polyamide membranes for desalination. Science 361, 682-686.

[9] Das, S.C., Hossain, J., Rahman, M.M., Talukder, M.R., 2025. Synthesis of amorphous carbon (a-C) thin films from the iodomethane chemical route by PE-CVD method for optoelectronic devices. Diam. Relat. Mater. 154, 112173.

[10] Faustini, M., Nicole, L., Ruiz-Hitzky, E., Sanchez, C., 2018. History of organic-inorganic hybrid materials: prehistory, art, science, and advanced applications. Adv. Funct. Mater. 28, 1704158.

[11] Fiss, B.G., Richard, A.J., Douglas, G., Kojic, M., Friščić, T., Moores, A., 2021. Mechanochemical methods for the transfer of electrons and exchange of ions: inorganic reactivity from nanoparticles to organometallics. Chem. Soc. Rev. 50, 8279-8318.

[12] Han, Z.L., Wang, P., Lu, Y.C., Jia, Z., Qu, S.X., Yang, W., 2022. A versatile hydrogel network-repairing strategy achieved by the covalent-like hydrogen bond interaction. Sci. Adv. 8, eabl5066.

[13] Hartmann, D., Thorwart, T., Müller, R., Thusek, J., Schwabedissen, J., Mix, A., Lamm, J.H., Neumann, B., Mitzel, N.W., Greb, L., 2021. The structure of bis(catecholato)silanes: phase adaptation by dynamic covalent chemistry of the Si-O bond. J. Am. Chem. Soc. 143, 18784-18793.

[14] He, Y.Q., Zhou, Y.Q., Cai, J.B., Feng, Y., Luo, B.H., Liu, M.X., 2022. Facile fabrication of hydrophobic paper by HDTMS modified chitin nanocrystals coating for food packaging. Food Hydrocoll. 133, 107915.

[15] Hou, J., Jiang, Q.W., 2018. Preparation of nanosized NaA zeolite and its surface modification by KH-550. Mater. Sci. Pol. 36, 638-643.

[16] Jia, H.Y., Cui, H.L., Wu, N.J., Deng, S.S., Wang, F., Wang, M.H., Wang, Z., 2025. Fabrication of superior flame-retardant phosphorylated chitosan biobased porous composites reinforced by superhydrophobic silicone interpenetrating crosslinking networks. Carbohydr. Polym. 347, 122540.

[17] Jia, J.J., Wang, Q.Q., Li, J.Y., Xu, Z.W., Li, H., Wei, D.H., Yuan, B.X., 2023. Liquid-assisted grinding accelerating the defluorinative coupling of gem-difluoroalkenes under ball-milling conditions. ACS Sustainable Chem. Eng. 12, 111-119.

[18] Jiang, Q.W., Tang, P.C., Chen, W.C., Han, J.T., Wu, R.D., Zhang, C.M., 2024. Fabrication and characterization of a novel superhydrophobic cotton fabric with integrated 3D graphene-Ag/TiO₂ aerogel for superior antibacterial performance, oil-water separation, and enhanced durability. Ind. Crops Prod. 222, 119882.

[19] Kim, H., Lee, H., 2025. Low-surface-energy capped hydrogel micropillar arrays for transparent superhydrophobic antifogging surfaces. Small 21, e09390.

[20] Kim, M.J., Lee, C., Shin, E.J., Lee, T.I., Kim, S., Jeong, J., Choi, J., Hwang, W.S., Im, S.G., Cho, B.J., 2021. Highly reliable charge trap-type organic non-volatile memory device using advanced band-engineered organic-inorganic hybrid dielectric stacks. Adv. Funct. Mater. 31, 2103291.

[21] Liu, Q., Wang, B.Y., Jiang, H.Q., Lu, Q.X., Wang, L.L., Yang, Y., Cheng, R.F., Gao, Q., Yang, L., Du, G.B., Gao, W., 2024. Optimization of durable superhydrophobic wood with superstrong ultraviolet resistance and chemical stability. Chem. Eng. J. 480, 148164.

[22] Liu, Z.K., Dong, Y.H., Qi, X.Q., Wang, R., Zhu, Z.L., Yan, C., Jiao, X.P., Li, S.P., Qie, L., Li, J., Huang, Y.H., 2022. Stretchable separator/current collector composite for superior battery safety. Energy Environ. Sci. 15, 5313-5323.

[23] Mahmood, N., Yuan, Z.S., Schmidt, J., Xu, C.C., 2016. Depolymerization of lignins and their applications for the preparation of polyols and rigid polyurethane foams: a review. Renew. Sustain. Energy Rev. 60, 317-329.

[24] Mallik, A.K., Moktadir, M.A., Rahman, M.A., Shahruzzaman, M., Rahman, M.M., 2022. Progress in surface-modified silicas for Cr(VI) adsorption: a review. J. Hazard. Mater. 423, 127041.

[25] Mehanna, Y.A., Sadler, E., Upton, R.L., Kempchinsky, A.G., Lu, Y., Crick, C.R., 2021. The challenges, achievements and applications of submersible superhydrophobic materials. Chem. Soc. Rev. 50, 6569-6612.

[26] Miao, Y., Xu, H.C., Wang, E.F., Liang, Y.P., Wang, Z.P., Sheng, K.C., Dai, C.P., Zhang, W.B., Huang, J.D., 2023. Ultralight, elastic, magnetic and superhydrophobic cellulose nanofibril based aerogel with layer-support structure designed for both excellent oil-water separation and efficient PM_2.5 removal. Sep. Purif. Technol. 327, 124986.

[27] Mishra, K., Siwal, S.S., Sithole, T., Singh, N., Hart, P., Thakur, V.K., 2024. Biorenewable materials for water remediation: the central role of cellulose in achieving sustainability. J. Bioresour. Bioprod. 9, 253-282.

[28] Miura, Y., Kashiwagi, T., Fukuda, T., Shichiri, A., Shiobara, T., Saitow, K.I., 2022. Near-room-temperature synthesis of alkoxysilanes and H₂ via mechanochemical ball milling. ACS Sustainable Chem. Eng. 10, 16159-16168.

[29] Mizutani, T., Ohta, H., Ueda, T., Kashiwagi, T., Fukuda, T., Shiobara, T., Saitow, K.I., 2023. Mechanochemically tailored silicon particles for efficient H₂ production: entropy and enthalpy engineering. ACS Sustainable Chem. Eng. 11, 11769-11780.

[30] Montazeri, M., Norouzbeigi, R., 2025. Ambient-dried, natural palm tree trunk-based hydrophobic foam for efficient oil sorption. Ind. Crops Prod. 225, 120551.

[31] Moseenkov, S.I., Kuznetsov, V.L., Zolotarev, N.A., Kolesov, B.A., Prosvirin, I.P., Ishchenko, A.V., Zavorin, A.V., 2023. Investigation of amorphous carbon in nanostructured carbon materials (a comparative study by TEM, XPS, Raman spectroscopy and XRD). Materials (Basel) 16, 1112.

[32] Preuss, M.D., Schnitzer, T., Jansen, S.A.H., Meskers, S.C.J., Kuster, T.H.R., Lou, X.W., Meijer, E.W., Vantomme, G., 2024. Functionalization of supramolecular polymers by dynamic covalent boroxine chemistry. Angew. Chem. Int. Ed. 63, e202402644.

[33] Sun, Y.C., Wang, M., Sun, R.C., 2015. Toward an understanding of inhomogeneities in structure of lignin in green solvents biorefinery. Part 1: fractionation and characterization of lignin. ACS Sustainable Chem. Eng. 3, 2443-2451.

[34] Tang, D.S., Yang, C.H., Shen, C., Li, Z.Y., Lyu, Z.Q., Yu, L.W., Huang, Q., Zhu, X.H., 2024. Inhibiting efflorescence of alkali-activated slag mortar by improving its hydrophobicity with methyl-terminated polydimethylsiloxane (PDMS): evidences showing the remained PDMS. Constr. Build. Mater. 443, 137688.

[35] Tang, M.W., Fang, X.R., Li, B.W., Xu, M., Wang, H.Y., Cai, S., 2022. Hydrophobic modification of wood using tetramethylcyclotetrasiloxane. Polymers (Basel) 14, 2077.

[36] Wang, D., Hu, C.S., Gu, J., Tu, D.Y., Wang, G., Jiang, M.L., Zhang, W.W., 2020. Bamboo surface coated with polymethylsilsesquioxane/Cu-containing nanoparticles (PMS/CuNP) xerogel for superhydrophobic and anti-mildew performance. J. Wood Sci. 66, 33.

[37] Wang, J.Y., Xiong, Z.M., Guo, L., Zhang, Y.F., Zhang, F., Du, F.P., 2025. Enhanced superhydrophobicity and durability of modified cotton cloth for efficient oil-water separation. Sep. Purif. Technol. 354, 128716.

[38] Wang, M.X., Chen, Y.M., Gao, Y., Hu, C., Hu, J., Tan, L., Yang, Z.M., 2018. Rapid self-recoverable hydrogels with high toughness and excellent conductivity. ACS Appl. Mater. Interfaces 10(31), 26610-26617.

[39] Wang, X., 2019. Challenges and outlook for catalytic direct amidation reactions. Nat. Catal. 2, 98-102.

[40] Wang, Z.L., Ren, Y.C., Wu, F.H., Qu, G.F., Chen, X.P., Yang, Y.Y., Wang, J., Lu, P., 2023. Advances in the research of carbon-, silicon-, and polymer-based superhydrophobic nanomaterials: synthesis and potential application. Adv. Colloid Interface Sci. 318, 102932.

[41] Wu, Z.M., Cai, C.C., Meng, X.J., Liu, Y.H., Liu, T., Zhao, Z.X., 2025. Robust and superhydrophobic CelluMOF triboelectric materials enabled by H-bond/ionic coordinations. Adv. Funct. Mater. 36, e14745.

[42] Yamamoto, T., Ashida, S., Inubuse, N., Shimizu, S., Miura, Y., Mizutani, T., Saitow, K.I., 2024. Room-temperature thermochemical water splitting: efficient mechanocatalytic hydrogen production. J. Mater. Chem. A 12, 30906-30918.

[43] Yao, H., Zhang, Y.J., Zhang, C., Xie, Z.L., Zheng, X.G., 2025. Strengthening the new-old mortar interfacial bonding through sodium methyl silicate comparing with rubber latex. Constr. Build. Mater. 475, 141181.

[44] Zha, H.Y., Zeng, L., Fu, H.Y., Zhuo, P., 2025. Engineering properties and microscopic mechanisms of carbonaceous mudstone modified by hydrophobic sodium methylsilicate. Case Stud. Constr. Mater. 23, e05385.

[45] Zhang, W., Zhu, K.R., Yang, C.C., Ai, Y., Gao, Y.H., Li, W., Zhao, D.Y., 2023. Monomicelle-induced assembly route toward low-dimensional mesoporous nanomaterials for catalysis. EcoEnergy 1, 85-107.

[46] Zhang, W.B., Zhai, X.L., Xiang, T.H., Zhou, M., Zang, D.L., Gao, Z.X., Wang, C.Y., 2017. Superhydrophobic melamine sponge with excellent surface selectivity and fire retardancy for oil absorption. J. Mater. Sci. 52, 73-85.

[47] Zhang, Q.H., Wang, G.L., Wen, X.L., Hoch, M., Mao, J., Shi, X.Y., 2022b. Moisture crosslinking and properties of ethylene-vinyl acetate rubber. Polymer (Guildf) 259, 125362.

[48] Zhang, R., Yao, W.Z., Qian, L., Sang, W., Yuan, Y., Du, M.C., Cheng, H., Chen, C., Qin, X., 2021. A practical and sustainable protocol for direct amidation of unactivated esters under transition-metal-free and solvent-free conditions. Green Chem. 23, 3972-3982.

[49] Zhang, Z.H., Chen, Z.Y., Tang, Y.H., Li, Y.T., Ma, D.Q., Zhang, G.D., Boukherroub, R., Cao, C.F., Gong, L.X., Song, P.G., Cao, K., Tang, L.C., 2022a. Silicone/graphene oxide co-cross-linked aerogels with wide-temperature mechanical flexibility, super-hydrophobicity and flame resistance for exceptional thermal insulation and oil/water separation. J. Mater. Sci. Technol. 114, 131-142.