Research And Application Of The Regulation Of Hydrophilicity/Hydrophobicity Of Bamboo Unit Surface

With the concept of sustainable construction,the use of natural materials has attracted more and more attention.Effective use of abundant renewable bamboo as decoration materials and building materials is of great significance to reducing carbon dioxide emissions and maintaining sustainable development.However,bamboo has the problems of poor wettability and gluing performance,and the shortcomings of single color,easy mildew,and flammability hinder the wide application of bamboo.In this study,the wettability of different bamboo units was modified to improve the surface properties of bamboo to improve the utilization range and utilization rate of bamboo.The specific research content of the thesis is as follows:(1)With the bamboo(bamboo with green and yellow)as a substrate,and it was modified with chlorinated isocyanic acid(CU)to regulate the surface wetting properties and improve the gluing performance of bamboo material.The effects of modifier concentration and treatment time on the wettability and surface energy of the bamboo strips were investigated.The results showed that when the concentration of CU is 3%and the treatment time is 3 h,the wetting performance of bamboo is the best,and the surface energy of bamboo is the largest.More importantly,the surface wettability of the modified bamboo stripes improved for the phenolic resin adhesive and urea-formaldehyde resin adhesive,and the impregnation and peeling test results were superior than those of the unmodified ones.(2)With the sliced bamboo veneer as a substrate,and MOF material as the base,layered double hydroxide(Co Ni-DH)was successfully prepared on the surface of the bamboo materials by in situ growth transformation method and subsequently coated with sodium laurate(La)to obtain a cobalt-nickel bimetallic hydroxide superhydrophobic layer(Co Ni-DH-La)coated with sodium laurate.The Co Ni-DH-La coating had favorable chemical stability and adhesion.The prepared Co Ni-DH-La coated bamboo chips(BS-Co Ni-DH-La)showed good performance in mildew resistance,flame retardancy and self-cleaning in following ways.No mildew grew on the superhydrophobic surface in the indoor mildew resistance test for 120 days;the oxygen index(LOI)of the superhydrophobic bamboo chips reached 29.9,and the LOI increased by 4.4 as opposed to the untreated ones.By changing the inorganic salt in the preparation process.By changing the type of inorganic salts in the preparation process,the bamboo could be given a variety of colors and exhibited promising potential for large-scale production.(3)With bamboo fiber as the experimental material,polyacrylamide(PAM)was employed to improve the wettability of bamboo fiber in desalination as a water transport material for solar water evaporation.The results showed that the hydrophilic modification of the modified bamboo fiber was obvious,and the water transport capacity of the modified bamboo fiber was significantly enhanced.After being soaked in salt water for one month,it could still maintain favorable water transport capacity and dimensional stability.The solar water evaporation rate of modified bamboo fiber tested reached 1.55 kg/(m~2·h)and the light-vapor conversion efficiency was 83.6%,which were much higher than that of unmodified one(0.42 kg/m~2·h and 14.7%).The hydrophilic modified bamboo fiber meets the requirements of solar water evaporation for water transportation materials.This not only expanded the application range of bamboo fibers and utilized clean solar energy,but also helped to solve the problem of water shortage.