Synthesis of Nano-Silicon Hybrid Alkyl Carboxylate to Inhibit Water and Chloride Transport in Concrete
Downloads
Concrete is vulnerable to water and chloride ingress because of its porous structure and hydrophilic hydration products. To address the poor dispersion, hydration interference, and strength loss often associated with conventional hydrophobic modifiers, this study synthesized a nano-silicon hybrid hydrophobic polymer ester (HPE) based on C12 alkyl carboxylate groups. Unlike conventional nano-silicon or alkyl-based modifiers that mainly rely on pore refinement or surface hydrophobization alone, HPE integrates C12 alkyl carboxylate groups with nano-silicon to construct multiple transport barriers. The effects of HPE dosage on concrete properties and transport-inhibition mechanisms were evaluated using contact angle, water absorption, electrical flux, rapid chloride migration, natural chloride diffusion, compressive strength, SEM, and MIP tests. HPE increased the contact angle from 14° to 78° and reduced long-term water absorption to 28% of the control. The electrical flux and chloride migration coefficient decreased to 48% and 62% of the control, respectively. MIP results showed reductions of 67.9% in the most probable pore diameter and 28.4% in total porosity. The enhanced durability is attributed to hydrophobic film formation, in-situ pore-blocking particles, and nano-silicon-assisted pore densification.
Downloads
[1] Yi, Y., Zhu, D., Guo, S., Zhang, Z., & Shi, C. (2020). A review on the deterioration and approaches to enhance the durability of concrete in the marine environment. Cement and Concrete Composites, 113. doi:10.1016/j.cemconcomp.2020.103695.
[2] Liu, P., Feng, C., Wang, F., Gao, Y., Yang, J., Zhang, W., & Yang, L. (2018). Hydrophobic and water-resisting behavior of Portland cement incorporated by oleic acid modified fly ash. Materials and Structures/Materiaux et Constructions, 51(2), 38. doi:10.1617/s11527-018-1161-8.
[3] Ruan, S., Gao, R., Tu, W., Li, G., Lu, J. X., Yan, D., & Poon, C. S. (2025). Hydration products and hybridisation mechanisms of hydrophobic cement pastes with alkyl-organosilanes. Cement and Concrete Composites, 163, 106208. doi:10.1016/j.cemconcomp.2025.106208.
[4] Zhao, J., Gao, X., Chen, S., Lin, H., Li, Z., & Lin, X. (2022). Hydrophobic or superhydrophobic modification of cement-based materials: A systematic review. Composites Part B: Engineering, 243, 243. doi:10.1016/j.compositesb.2022.110104.
[5] Cheng, Y., Qin, C., & Huang, Q. (2024). Hydrophobic cement: Concept, preparation and application. Construction and Building Materials, 449. doi:10.1016/j.conbuildmat.2024.138444.
[6] Abdrassilov, D., Aniskin, A., Shakhmov, Z., & Lukpanov, R. (2026). Hydrophobic Modification of Concrete Using a Hydrophobizing Admixture. Construction Materials, 6(1), 3. doi:10.3390/constrmater6010003.
[7] Tittarelli, F., & Moriconi, G. (2011). Comparison between surface and bulk hydrophobic treatment against corrosion of galvanized reinforcing steel in concrete. Cement and Concrete Research, 41(6), 609–614. doi:10.1016/j.cemconres.2011.03.011.
[8] Elnaggar, E. M., Elsokkary, T. M., Shohide, M. A., El-Sabbagh, B. A., & Abdel-Gawwad, H. A. (2019). Surface protection of concrete by new protective coating. Construction and Building Materials, 220, 245–252. doi:10.1016/j.conbuildmat.2019.06.026.
[9] Wang, X., & Lin, Z. (2021). Robust, hydrophobic anti-corrosion coating prepared by PDMS modified epoxy composite with graphite nanoplatelets/nano-silica hybrid nanofillers. Surface and Coatings Technology, 421. doi:10.1016/j.surfcoat.2021.127440.
[10] Wang, D., He, L., Wu, Y., Li, Y., Hu, W., Ma, T., Luo, S., Song, J., Sun, W., & Zhang, G. (2024). Alkali-activated organogeopolymers with volumetric superhydrophobicity. Cement and Concrete Composites, 145, 105336. doi:10.1016/j.cemconcomp.2023.105336.
[11] Zarzuela Sánchez, R., González-Coneo, J., Luna, M., Díaz, A., & Mosquera, M. J. (2023). Studying the bulk hydrophobization of cement mortars by the combination of alkylalkoxysilane admixture and fluoropolymer-functionalized aggregate. Journal of Building Engineering, 65, 105771. doi:10.1016/j.jobe.2022.105771.
[12] Han, K., Yin, B., Jia, X., Xu, H., Li, T., Wang, P., & Hou, D. (2024). One-step hybridization of silane hydrolysis and silica mineralization for enhanced superhydrophobic coating on cement-based materials. Journal of Building Engineering, 94, 109824. doi:10.1016/j.jobe.2024.109824.
[13] Hodul, J., Beníková, T., Drochytka, R., & Borg, R. P. (2025). The Examination of the Effect of Water-Soluble Hydrophobic Agents on Physical–Mechanical Parameters and Resistance to Aggressive Environment of Concrete. Coatings, 15(2), 175. doi:10.3390/coatings15020175.
[14] She, W., Zheng, Z., Zhang, Q., Zuo, W., Yang, J., Zhang, Y., Zheng, L., Hong, J., & Miao, C. (2020). Predesigning matrix-directed super-hydrophobization and hierarchical strengthening of cement foam. Cement and Concrete Research, 131. doi:10.1016/j.cemconres.2020.106029.
[15] Liang, C., Zhao, P., Liu, L., Wang, S., Wang, S., Sobolev, K., & Lu, L. (2023). Fabrication of bulk hydrophobic cement-based materials with ultra-high impermeability. Journal of Building Engineering, 63, 105492. doi:10.1016/j.jobe.2022.105492.
[16] Liang, C., Chen, M., Jiang, D., Hou, P., Zhao, D., Wang, S., Yu, Z., Zhao, P., & Lu, L. (2025). Synthesis of MNS@PDMS emulsion for enhancing hydrophobicity in cementitious materials with limited strength loss. Cement and Concrete Composites, 157, 105875. doi:10.1016/j.cemconcomp.2024.105875.
[17] Zhang, D., Zhu, H., Wu, Q., Yang, T., Yin, Z., & Tian, L. (2023). Investigation of the hydrophobicity and microstructure of fly ash-slag geopolymer modified by polydimethylsiloxane. Construction and Building Materials, 369, 130540. doi:10.1016/j.conbuildmat.2023.130540.
[18] Gao, R., Mao, J., Ruan, S., Tu, W., Wang, Y., & Yan, D. (2025). Early-Age Properties and Reaction of Hydrophobic Portland Cement and Alkali-Activated Fly Ash–Slag Pastes with Alkyl Silanes. Buildings, 15(16), 2966. doi:10.3390/buildings15162966.
[19] Wang, X., Zhang, W., Wang, Y., Wu, H., Danzeng, D., & Meng, Y. (2025). Assessment of the Wettability and Mechanical Properties of Stearic-Acid-Modified Hydrophobic Cementitious Materials. Coatings, 15(1), 100. doi:10.3390/coatings15010100.
[20] Wang, W., Wang, S., Yao, D., Wang, X., Yu, X., & Zhang, Y. (2020). Fabrication of all-dimensional superhydrophobic mortar with enhanced waterproof ability and freeze-thaw resistance. Construction and Building Materials, 238, 238. doi:10.1016/j.conbuildmat.2019.117626.
[21] Meng, F., Han, K., Guo, T., Shu, X., Guo, Y., Dong, L., Cai, J., & Ran, Q. (2025). Elucidating the effects and mechanisms of OTES@silica nano capsules on water resistance and compressive strength of cement paste. Cement and Concrete Research, 198, 108003. doi:10.1016/j.cemconres.2025.108003.
[22] Xie, M., Zhong, Y., Li, Z., Lei, F., & Jiang, Z. (2021). Study on alkylsilane-incorporated cement composites: Hydration mechanism and mechanical properties effects. Cement and Concrete Composites, 122, 104161. doi:10.1016/j.cemconcomp.2021.104161.
[23] Ormellese, M., Lazzari, L., Goidanich, S., Fumagalli, G., & Brenna, A. (2009). A study of organic substances as inhibitors for chloride-induced corrosion in concrete. Corrosion Science, 51(12), 2959–2968. doi:10.1016/j.corsci.2009.08.018.
[24] Diamanti, M. V., Pérez Rosales, E. A., Raffaini, G., Ganazzoli, F., Brenna, A., Pedeferri, M., & Ormellese, M. (2015). Molecular modelling and electrochemical evaluation of organic inhibitors in concrete. Corrosion Science, 100, 231–241. doi:10.1016/j.corsci.2015.07.034.
[25] Bhuvaneshwari, B., Selvaraj, A., Iyer, N. R., & Ravikumar, L. (2015). Electrochemical investigations on the performance of newly synthesized azomethine polyester on rebar corrosion. Materials and Corrosion, 66(4), 387–395. doi:10.1002/maco.201307472.
[26] Zhi, F., Jiang, L., Jin, M., Xu, P., Xiao, B., Jiang, Q., Chen, L., & Gu, Y. (2020). Inhibition effect and mechanism of polyacrylamide for steel corrosion in simulated concrete pore solution. Construction and Building Materials, 259. doi:10.1016/j.conbuildmat.2020.120425.
[27] Chen, R., Liu, J., & Mu, S. (2022). Chloride ion penetration resistance and microstructural modification of concrete with the addition of calcium stearate. Construction and Building Materials, 321, 126188. doi:10.1016/j.conbuildmat.2021.126188.
[28] Chen, J., Zhang, Y., Hou, D., Yu, J., Zhao, T., & Yin, B. (2019). Experiment and molecular dynamics study on the mechanism for hydrophobic impregnation in cement-based materials: A case of octadecane carboxylic acid. Construction and Building Materials, 229. doi:10.1016/j.conbuildmat.2019.116871.
[29] Yang, H.-M., Singh, J. K., Kwon, S.-J., Goudar, S. K., Shivaprasad, K. N., & Lee, S. (2026). Electrochemical and microstructural degradation behaviour of stearate modified cement mortar in chloride environments. Npj Materials Degradation. doi:10.1038/s41529-026-00783-y.
[30] Feng, Z., Wang, F., Xie, T., Ou, J., Xue, M., & Li, W. (2019). Integral hydrophobic concrete without using silane. Construction and Building Materials, 227, 116678. doi:10.1016/j.conbuildmat.2019.116678.
[31] Gong, W., Zhang, Y., Yuan, L., Zhu, B., Yang, H., Hou, Y., Li, H., Lv, Y., & Jin, W. (2025). Study on the preparation and performance of synchronous setting integration in hydrophobic-ordinary concrete. Construction and Building Materials, 504, 144673. doi:10.1016/j.conbuildmat.2025.144673.
[32] Wang, H., Zhang, L., Wang, D., Geng, D., Dong, Z., & Su, Z. (2022). Stability of Phenyl Copolymer-Graphene Oxide Composites in High-Alkali and/or -Calcium Environments: Implications for Strengthening and Toughening Cement-Based Materials. ACS Applied Nano Materials, 5(3), 4038–4047. doi:10.1021/acsanm.2c00023.
[33] Yang, L., Hu, X., Liu, Y., Zhou, D., Yuan, B., Liu, S., Luo, Z., Li, X., Jin, D., & Xu, F. (2026). Multiscale characterization of geopolymers modified with alkali-catalyzed nano-silica: Effects on dispersion and mechanical properties. Cement and Concrete Composites, 165. doi:10.1016/j.cemconcomp.2025.106324.
[34] Hilbig, H., Gutberlet, T., & Beddoe, R. E. (2024). Acid attack on hydrated cement: effect of organic acids on the degradation process. Materials and Structures/Materiaux et Constructions, 57(4), 83. doi:10.1617/s11527-024-02360-8.
[35] Lin, J., Shamsaei, E., Basquiroto de Souza, F., Sagoe-Crentsil, K., & Duan, W. H. (2020). Dispersion of graphene oxide–silica nanohybrids in alkaline environment for improving ordinary Portland cement composites. Cement and Concrete Composites, 106. doi:10.1016/j.cemconcomp.2019.103488.
[36] Mora, E., González, G., Romero, P., & Castellón, E. (2019). Control of water absorption in concrete materials by modification with hybrid hydrophobic silica particles. Construction and Building Materials, 221, 210–218. doi:10.1016/j.conbuildmat.2019.06.086.
[37] Karthick, S., Park, D. J., Lee, Y. S., Saraswathy, V., Lee, H. S., Jang, H. O., & Choi, H. J. (2018). Development of water-repellent cement mortar using silane enriched with nanomaterials. Progress in Organic Coatings, 125, 48–60. doi:10.1016/j.porgcoat.2018.08.021.
[38] Li, H., & Guo, X. (2024). Fabricating hydrophobic silica fume to improve mechanical strength and anti-corrosion of integral hydrophobic cement mortar and its carbon emission assessment. Journal of Cleaner Production, 439, 140857. doi:10.1016/j.jclepro.2024.140857.
[39] Xiang, Y., Duan, H., Yan, C., Zhao, T., & Zhang, H. (2026). Effect of PDMS@PMMA hydrophobic microcapsules on water resistance and hydration characteristics of cement paste. Construction and Building Materials, 506, 145048. doi:10.1016/j.conbuildmat.2025.145048.
[40] Yang, J., She, W., Zuo, W., & Zhang, Q. (2021). Rational application of nano-SiO2 in cement paste incorporated with silane: counterbalancing and synergistic effects. Cement and Concrete Composites, 118, 103959. doi:10.1016/j.cemconcomp.2021.103959.
[41] Zhang, H., Mu, S., Cai, J., & Chen, R. (2021). The impact of carboxylic acid type hydrophobic agent on compressive strength of cementitious materials. Construction and Building Materials, 291, 123315. doi:10.1016/j.conbuildmat.2021.123315.
[42] Zhang, H., Zhou, Y., Mu, S., Cai, J., Hong, J., Liu, J., & Zhao, Y. (2022). Pore Structure and Permeability of Cementitious Materials Containing a Carboxylic Acid Type Hydrophobic Agent. Frontiers in Materials, 9, 907638. doi:10.3389/fmats.2022.907638.
[43] Castro, J., Bentz, D., & Weiss, J. (2011). Effect of sample conditioning on the water absorption of concrete. Cement and Concrete Composites, 33(8), 805–813. doi:10.1016/j.cemconcomp.2011.05.007.
[44] Wang, R., Liu, K., Li, L., He, X., Yang, Y., & Chen, B. (2024). Influence of HPMC on the capillary water absorption, pore structure and hydration of the calcium aluminate cement-hemihydrate gypsum mortar. Journal of Thermal Analysis and Calorimetry, 149(11), 5203–5214. doi:10.1007/s10973-024-13202-8.
[45] Luo, J., Xu, Y., Chu, H., Yang, L., Song, Z., Jin, W., Wang, X., & Xue, Y. (2023). Research on the Performance of Superhydrophobic Cement-Based Materials Based on Composite Hydrophobic Agents. Materials, 16(19), 6592. doi:10.3390/ma16196592.
[46] Yu, Z., Jiang, D., Liang, C., Lu, S., Wu, Y., Wang, K., Zhou, Y., & Zhao, P. (2025). Effects of hydrophobic cement powder on mechanical strength and impermeability of cement-based materials. Construction and Building Materials, 489, 142202. doi:10.1016/j.conbuildmat.2025.142202.
[47] Liu, J., Cai, J., Shi, L., Liu, J., Mu, S., & Hong, J. (2018). The inhibition behavior of a water-soluble silane for reinforcing steel in 3.5% NaCl saturated Ca (OH) 2 solution. Construction and Building Materials, 189, 95-101. doi:10.1016/j.conbuildmat.2018.08.151.
[48] Tittarelli, F., & Moriconi, G. (2010). The effect of silane-based hydrophobic admixture on corrosion of galvanized reinforcing steel in concrete. Corrosion Science, 52(9), 2958–2963. doi:10.1016/j.corsci.2010.05.008.
[49] Zhao, H., Jiang, D., Liang, C., Zhao, D., Yu, Z., Zhang, T., & Zhao, P. (2026). Controllable preparation of engineered hydrophobic slag powder: Synergistically enhancing the strength and impermeability of cement-based materials. Construction and Building Materials, 518, 145825. doi:10.1016/j.conbuildmat.2026.145825.
[50] Yu, J., Li, S., Hou, D., Jin, Z., & Liu, Q. (2019). Hydrophobic silane coating films for the inhibition of water ingress into the nanometer pore of calcium silicate hydrate gels. Physical Chemistry Chemical Physics, 21(35), 19026–19038. doi:10.1039/c9cp03266e.
[51] Yang, C. C., Cho, S. W., & Wang, L. C. (2006). The relationship between pore structure and chloride diffusivity from ponding test in cement-based materials. Materials Chemistry and Physics, 100(2–3), 203–210. doi:10.1016/j.matchemphys.2005.12.032.
[52] Sakai, Y. (2019). Relationship between pore structure and chloride diffusion in cementitious materials. Construction and Building Materials, 229, 116868. doi:10.1016/j.conbuildmat.2019.116868.
- Authors retain all copyrights. It is noticeable that authors will not be forced to sign any copyright transfer agreements.
- This work (including HTML and PDF Files) is licensed under a Creative Commons Attribution 4.0 International License.
