桉木粉在低共熔溶剂中制备纳米结晶纤维素

Preparation of Cellulose Nanocrystals from Eucalyptus Powder by Deep Eutectic Solvent

采用氯化胆碱-丙三醇-聚乙二醇200混合溶剂液化桉木粉的方法分离纤维素,再通过氯化胆碱-草酸二水合物低共熔溶剂(DES)在不同的条件下处理提取的纤维素制备纳米结晶纤维素(CNC)。探讨了固液比、温度以及时间对CNC得率的影响,用扫描电镜、透射电镜、红外光谱、X-射线衍射、Zeta电位、紫外可见光分析对制备的CNC进行了表征。结果表明,在固液比1∶100,温度100℃,反应时间4h的条件下,CNC的得率最高,可以达到90.06%;制备的CNC呈棒状结构,直径为3~13nm,长度为100~300nm;结晶度相比于原料纤维素略有降低,纤维素结构没有发生大的变化,仍然呈纤维素Ⅰ型结晶。

Cellulose was separated from eucalyptus wood powder by partial liquefaction using choline chloride-PEG200-glycerin solvent as the liquefying reagent. The separated cellulose was then treated with choline chloride-oxalic acid dihydrate eutectic solvent under different conditions to prepare cellulose nanocrystal. The effect of different reaction conditions on the yield of cellulose nanocrystal was discussed. And the cellulose nanocrystals were characterized by scanning electron microscopy,transmission electron microscopy,Fourier transform infrared spectroscopy,X-ray diffraction,Zeta potential and UV—vis spectra. The results showed that the optimal reaction conditions are solid-liquid ratio 1∶ 100 at 100℃ for 4 h,the yield of cellulose nanocrystal can reach 90. 06%. The cellulose nanocrystals were rod-shaped,between 100 and 300 nm long,with a diameter ranging from 3 to 13 nm. The molecular cellulose type I crystalline structure remained intact while the crystallinity decrease slightly during the preparation of cellulose nanocrystals.