纳米纤维素自愈合水凝胶的构筑

Preparation of Self-healing Hydrogels Based on Cellulose Nanofibrils

针对目前纳米纤维素(cellulose nanofibrils,CNF)制备方法存在的产率低、能耗高、成本高以及环境污染大等问题,采用酶预处理结合超声波法制备纳米纤维素,先通过酶预处理断裂部分纤维素分子链,再用超声波解离纤维素,确保制备过程的绿色、环保。随后用高碘酸钠氧化制得的纳米纤维素,形成2,3-二醛基纳米纤维素,使其与壳聚糖发生席夫碱反应,构筑具有自愈合性能及pH响应能力的纳米纤维素水凝胶。

In view of the current research on the preparation of cellulose nanofibrils (CNF) by mechanical treatment or acid hydrolysis, there are some problems such as low yield, large energy consumption, high cost and serious environmental pollution.Enzyme treatment and ultrasonic cavitation were combined to prepare CNF in a green and efficient way.By cellulase pretreatment, the fiber surface was corroded, and the fiber chain was cut and shortened, which led to the degradation of the cellulose macromolecule into the segment of low degree of polymerization.CNF were obtained by further ultrasonic cavitation treatment.And then, the enzymatic CNF was highly oxidized by sodium periodate to prepare 2,3-dialdehyde-based CNF.Thus, a CNF-based hydrogel with self-healing properties and pH responsiveness was constructed by making it react with chitosan through Schiff base reaction.