Wu Cong, Hou Dongshuai, Yin Bing, Li Shaochun, Wang Xinpeng
School of Civil Engineering, Qingdao University of Technology, Qingdao 266033, China.
ACS Appl Mater Interfaces. 2022 Sep 7;14(35):40297-40312. doi: 10.1021/acsami.2c08981. Epub 2022 Aug 24.
The construction of multiple microstructures is a significant measure in improving the protective performance of composite polymer coatings. In this paper, a novel polystyrene acrylate-highly hydrophobic polysiloxane composite emulsion was fabricated by innovatively integrating the core-shell emulsion method and Pickering emulsion method through the interfacial stabilization and molecular polymerization regulation of graphene oxide, achieving a significant improvement in the compatibility of the thermoplastic core with a thermoset shell. The bonding degree between the polystyrene acrylate (PSA) component and the siloxane component is significantly improved in the synthesized composite emulsions, achieving the dual protection of the cementitious substrate with surface shielding and internal crystalline hydrophobicity. The capillary water absorption of the concrete treated with Pickering emulsions is reduced by over 98.3% with high hydrophobicity and low permeability. Meanwhile, the absolute ζ-potential and impedance of composite membranes reach over 45 mV and 10 ohms, respectively, giving the cementitious substrate excellent resistance to ionic attack and acid/alkaline corrosion. In addition, the composite membranes have excellent resistance to tensile cracking and physical erosion, maintaining a favorable adhesion level and plastic deformation under acid/alkaline attack and thermal aging, respectively.
构建多重微观结构是提高复合聚合物涂层防护性能的一项重要措施。本文通过氧化石墨烯的界面稳定作用和分子聚合调控,创新性地将核壳乳液法与皮克林乳液法相结合,制备了一种新型的聚苯乙烯丙烯酸酯-高疏水性聚硅氧烷复合乳液,实现了热塑性核与热固性壳相容性的显著提升。在合成的复合乳液中,聚苯乙烯丙烯酸酯(PSA)组分与硅氧烷组分之间的结合程度显著提高,实现了对胶凝基材的表面屏蔽和内部结晶疏水性的双重保护。用皮克林乳液处理的混凝土毛细吸水率降低了98.3%以上,具有高疏水性和低渗透性。同时,复合膜的绝对ζ电位和阻抗分别达到45 mV以上和10欧姆以上,赋予胶凝基材优异的抗离子侵蚀和酸碱腐蚀性能。此外,复合膜具有优异的抗拉伸开裂和物理侵蚀性能,在酸碱侵蚀和热老化条件下分别保持良好的附着力水平和塑性变形能力。