超声协同TEMPO氧化制备阔叶木氧化纳米纤维素

Preparation of Hardwood Nanocellulose by TEMPO Oxidation Assisted with Ultrasonic Treatment

采用超声协同的TEMPO/NaBr/NaClO催化氧化体系制备阔叶木氧化纳米纤维素,探究氧化过程中,随氧化程度增大,纤维素的形貌、尺寸、羧基含量、Zeta电位、得率的变化规律。结果表明,超声作用显著提高了氧化反应速率及羧基含量,且粒径明显低于TEMPO氧化。借助SEM扫描电镜可以看出,超声波的空化作用可以破坏阔叶木纤维的层状结构,提高了纤维的比表面积,对TEMPO氧化起到了促进作用。

Hardwood nanocellulose was prepared by TEMPO/NaBr/NaClO catalytic oxidation system assisted with ultrasound.The morphology,size,carboxyl content and yield of the cellulose were investigated during the oxidation process.Ultrasound-assisted TEMPO oxidation was accelerated,resulting in higher degree of carboxyl content,and significantly lower fibril size than that of TEMPO oxidation.Visualized by SEM,the acoustic cavitation of ultrasonic can destroy the lamellar structure of hardwood fibers and increase the specific surface area of the fibrils.Eventually,TEMPO oxidation was promoted.