Modification and Characterization of Nano-Ag/TiO2 Antimold Agent for Wood Materials

Nano-Ag/TiO2 exhibits effective antimicrobial activities; however, its tendency to aggregate limits its application in wood products for improved antimold properties. In this study, nano-Ag/TiO2 was modified by a silane coupling agent (gamma-aminopropyltriethoxysilane [KH-550]) and then loaded into wood via vacuum impregnation. The effects of KH-550 concentration, Ag/TiO2 concentration, reaction temperature, and incubation time on the antimold rate, loading amount, and leach resistance for wood materials were investigated. Results showed that the antimold rate, loading amount, and fixation rate of mold-proof-treated wood was strengthened by KH-550 modification. The binding affinity and surface energy of nano-Ag/TiO2 was reduced, and the dispersivity of nano-Ag/TiO2 particles was improved after modification. Observation by field emission scanning electron microscopy showed that the modified nano-Ag/TiO2 penetrated into the wood tracheids and formed a tight flocculent structure. X-ray diffractive analysis confirmed that modification did not affect the anatase diffraction pattern of nano-Ag/TiO2 or its photocatalytic and antimicrobial activities. Characterization by Fourier transform infrared spectroscopy showed that modified nano-Ag/TiO2 efficiently cross-linked with wood hydroxyl groups. This work provided a simple and effective method to develop a novel nano-Ag/TiO2 antimold agent for wood mold-proof treatment.