Preparation and properties of nano-TiO2-Chinese herbal medicine composite wood

Abstract

The sol-gel method was used to make nano-TiO2 and five Chinese herbal medicines of Sophora flavescens Alt., Hypericum perforatum L., Cnidium monnieri (L.) Cuss., Kochia scoparia (L.), and Zanthoxylum bungeanum Maxim. to prepare five kinds of nano-TiO2-Chinese herbal medicine composite anti-degradative wood. Populus tomentosa Carr was chosen as the wood sample. Indoor decay resistance test results showed that the resistance to weight gain and decay of nano-TiO2-Chinese herbal medicine composite anti-degradative wood noticeably increased compared with either Chinese herbal medicine modified wood or nano-TiO2 modified wood, reaching a strong decay resistance level. The results of the anti-loss test showed that the magnitude of loss of wood samples treated with nano-TiO2 and Chinese herbal medicine was noticeably reduced compared with that with just Chinese herbal medicine. It was found by scanning electron microscopy that the nano-TiO2 particles and the Chinese herbal medicine enter the wood cell cavity, and the wood vessels and pits were the main permeation channels. Fourier transform infrared analysis results showed that nano-TiO2 could not only enter the wood interior, and associate with wood components through physical adsorption to form hydrogen bonds, but also through the carboxyl groups in cellulose and hemicellulose, or the phenolic hydroxyl group in lignin, forming a coordinated chemical bond to fix it in the wood component.