毛竹干燥过程中水分变化对其纤维素结晶结构的影响OA北大核心CSTPCD

Water is a crucial factor affecting bamboo's the processing and utilization.The mechanism of water in bamboo can be traced to cellulose crystal structure of bamboo cell walls.X-ray diffraction(XRD)is a useful technique for revealing the structure at the crystalline scale.Therefore,XRD was used to analyze the changes in the crystalline structure of Moso bamboo during dehydration.The results indicated that the crystallinity of Moso bamboo decreased with decreasing moisture content(from 143.9％to 5.7％).The d-spacing and crystalline size of the(200)crystal plane increased with decreasing moisture content.The increment of d-spacing was 0.07 Å,representing a 1.8％increase.This result was mainly attributed to the dehydration-induced shrinkage of amorphous substances,which generated tensile stress in the crystalline region and increased both d-spacing and crystalline size.Conversely,the d-spacing and crystalline size of the(004)crystal plane decreased as moisture content decreased.This might be due to the spiral contraction of the cellulose molecular chains after losing water,which leads to a reduction in crystal length.In conclusion,the crystalline structure underwent transverse expansion and longitudinal contraction after the dehydration of Moso bamboo.This study enriches the theoretical understanding of Moso bamboo's interaction with moisture by revealing the changes in cellulose crystal structure during moisture loss.It also provides a scientific foundation in crystalline aspects for applications such as bamboo drying and crack prevention.