Thermal annealing-mediated bead-chained hollow silica nanoparticles for mechanically robust, anti-fog coating with anisotropic adhesion

The inherent isotropic adhesion characteristics of acrylic resin matrices limit their utility in anti-fogging applications. While high nanoparticles -loading acrylic resin coatings exhibit enhanced mechanical durability, they compromise the essential high optical transmittance of transparent substrates. In this study, we employed polymer capillary infiltration to securely anchor soft-template-synthesized hollow silica nanoparticles in disordered assemblies onto coating surfaces without degrading substrate transmittance (90%), forming structurally continuous anti-fog coatings. Our results demonstrated that Bead-Chained Hollow Silica Nanoparticles (BHSNPs) provided greater molecular entanglement sites within the polymer matrix compared to hollow nanosphere, significantly reinforcing coating mechanical strength, the viscosity increased seven times, modulus increased three times, compared to pure acrylic resin in the absence of BHSNPs. Furthermore, surface integration of these BHSNPs created low-adhesion regions, thereby establishing an anisotropic adhesion interface, while enhancing surface wear resistance. This methodology presented a scalable fabrication strategy for developing mechanically robust, optically transparent anti-fog coatings adaptable to diverse application scenarios. The Bead-Chained Hollow Silica Nanoparticles (BHSNPs) is obtained via the soft template method, which effectively enhances the modulus of non-covalently crosslinked acrylic resins. Thermal annealing anchors the BHSNPs to the coating surface, resolving the inherent isotropic adhesion properties of acrylic resins. This ensures strong adhesion between the coating and substrate while imparting long-lasting anti-fog capabilities to the coating. • Bead-Chained Hollow Silica Nanoparticles (BHSNPs) were synthesized via a soft-template method. • Thermal annealing-mediated polymer capillary infiltration firmly anchors BHSNP to the coating surface. • Achieved both high optical transmittance (90%) and high mechanical robustness. • Localized low-adhesion zones form on the surface, transforming isotropic adhesion into anisotropic adhesion. • Maintained stable anti-fog performance and consistent light transmittance, after repeated mechanical abrasion.