A Study On Hydrophobicity And Photocatalytic Properties Of Wood Surface Modified By Graphitic Carbon Nitride

As a sustainable renewable green material,wood is widely used in various fields.However,wood has the disadvantages of being susceptible to be polluted,water absorption swelling,and poor dimensional stability.These natural defects can greatly reduce the wood durability,shorten the life of wood and limit the range of wood applications.This study is dedicated to endow wood with photocatalytic activity,improve hydrophobicity and dimensional stability of wood,aiming at the functional improvement and exploring an environmentally friendly,simple and effective wood modification method.The main contents are as follows:In this study,the wood surface was modified by directly loading graphitic-phase carbon nitride(g-C3N4).Treating bulk g-C3N4 with different concentrations of hydrochloric acid.The wood surface was modified by vacuum impregnation using protonated g-C3N4.The protonated g-C3N4 which is most suitable for modifing the wood surface is the g-C3N4 obtained by 12 mol/L hydrochloric acid.And g-C3N4 is successfully loading on wood surface.G-C3N4 imparts photocatalytic ability to wood and there is a slight increase in the dimensional stability of wood after pretreatment.In order to strengthen the modification effect,the modified wood was directly heat treated after impregnating g-C3N4.The heat treatment can significantly improve the firmness of g-C3N4 on the wood surface.As the amount of g-C3N4 fixed increase,the photocatalytic activity of the modified wood also increase.The heat treatment improves the hydrophobicity and dimensional stability of the modified wood.Based on photocatalytic and hydrophobic properties,the optimum heat treatment temperature for the modified wood is 210?.In order to further improve the modified wood hydrophobicity and dimensional stability,g-C3N4/TiO2/OTS composite material is used to modify the wood.The g-C3N4/TiO2 composite coating is loaded on wood surface by vacuum impregnation combining with liquid phase precipitation,and then the hydrophobic modification is carried out by using OTS with low surface energy.Thus,a wood-based composite material having photocatalytic activity,hydrophobicity and dimensional stability is obtained.The doping of g-C3N4 and TiO2 effectively enhances the photocatalytic activity of both.And it has excellent photocatalytic ability under ultraviolet light.Moreover,the dimensional stability and hydrophobicity of the modified wood are greatly improved.