Functionalization and application expansion of nano-Ca(OH)2 realized via three-phase AC33-Ca(O)2/Bi4Ti3O12 functional composite materials

Abstract Nano-Ca(OH) 2 is a promising material for mural restoration due to compatibility with plaster layers. However, the practical application of conventional nano-Ca(OH) 2 is limited by poor permeability, inadequate consolidation strength, and insufficient antimicrobial activity. Herein, we propose a three-phase functional composite strategy that integrates antimicrobial and mechanical-consolidation components onto nano-Ca(OH) 2 matrix to enhance its performance. High-permeability nano-Ca(OH) 2 was synthesized via facet-selective inhibition and composited with Bi 4 Ti 3 O 12 to form an antibacterial heterojunction, which presents 99% antibacterial rate against mural bacteria via efficient charge separation. Additionally, the consolidation performance was improved after incorporating AC33. When mass ratio of AC33 to heterojunction was 20:1, the flexural strength of the consolidated simulated mural became 2.4 times that of samples treated with Ca(OH) 2 , owing to enhanced interfacial adhesion provided by AC33. Meanwhile, the antibacterial rate remained above 96% with negligible color change. This work presents an approach for functionalizing nano-Ca(OH) 2 to satisfy demand of mural restoration.