AFM study of crystalline cellulose in the cell walls of straw

Crystalline cellulose in the cell walls of straw was studied by atomic force microscopy (AFM). The samples were first treated and then observed by AFM under dimethylsulfoxide (DMSO). The crystalline regions were located and two allomorphs of crystalline cellulose, triclinic I_α and monoclinic I_β phases, were identified. In most crystalline regions, the I_α and I_β phases are intimately associated, with the I_β phase more abundant than the I_α phase. In some small domains only one phase with long‐range order was observed. It was demonstrated that in these one‐phase domains, I_α phase crystals always have their (010) plane lying parallel to the cell wall surface and I_β phase crystals with (110) plane lying parallel. Copyright © 2005 Society of Chemical Industry