Influence of ultrasound treatment on accessibility and regioselective oxidation reactivity of cellulose.

Cellulose fibers were treated with ultrasound in order to improve the accessibility and the reactivity of cellulose. The influence of ultrasound treatment on changes of morphology structure, accessibility and oxidation reactivity of cellulose with sodium periodate were discussed. The results revealed an increase in cellulose's accessibility in terms of water retention value (WRV) with increasing ultrasound treatment time, corresponding to 73.0%, 75.6%, 80.8%, 98.7% and 119.0% after treated for 0, 90, 180, 360 and 720 s, respectively. Furthermore, the regioselective oxidation reactivity of cellulose with sodium periodate was also successfully improved by the ultrasound treatment. However, no significant changes in crystallinity of cellulose were noted after ultrasound treatment. The oxidized products dialdehyde cellulose (DAC) was further characterized by means of FTIR, X-ray diffraction and SEM.