Controlled Assembly of Glucuronoxylans onto Cellulose Fibres

Summary

In this study we have shown that cellulose fibres can be coated with regular micron-sized particles by controlling the assembly process of xylans on the cellulose surfaces. When cotton linters were exposed to a 5% water solution of xylan from birchwood at 110°C, 2 h, pH 8, the substrates showed an increase in weight of approximately 6.5%, and visualization by AFM revealed regular particles on the fibre surfaces. The surface modification process was optimized using an experimental design where time, temperature, and pH were varied. The experiments showed that the amount of xylan deposited on the fibres could be varied from 2% up to 20% depending on treatment conditions. The temperature and time were the most important parameters, while pH was not important in the investigated region. The morphology of the deposited xylan layer, as shown by SEM, was dependent on the amount of xylan on the fibre surfaces. At low yield the fibres were coated with a homogenous layer, while at higher yields (20%) regular particles of micron size were identified by AFM analysis. The mechanism of this assembly process of xylan on cellulose fibre surfaces is discussed.