Waterproof aerated bricks from stone powder waste through nano-TiO2 structured hydrophobic surface modification

Abstract

To eliminate the negative impacts of waste stone powder that arises from stone processing, the waste was recycled into aerated bricks with a porous structure that exhibited exceptional properties when applied in buildings. However, the pores easily absorb rainwater and dust, causing performance degradation and mold growth inside. In this paper, we have developed through hydrothermal reactions an environmentally friendly aqueous suspension, containing homemade highly dispersive TiO2 nanoparticles modified with super-hydrophobic groups on the surface. The suspension was coated onto the aerated bricks, creating a super-hydrophobic surface with a highly textured hierarchical structure. A large contact angle of 146 degrees tested on the surface and negligible water absorption for 24 h immersion demonstrate the excellent water proofing performance, holding a great promise for large scale applications in construction and buildings.