Investigation of Composite Protective Coatings Coregulated by Core–Shell Structures and Graphene Oxide Interfaces

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 109 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.