罗布麻秆中纤维素提取及其气凝胶的制备

Cellulose extraction from apocynum venetum stalk and its preparation of aerogel

为实现罗布麻秆的高附加值利用,以罗布麻秆为原料,选用硝酸/乙醇法提取纤维素,通过单因素试验和正交试验优化的提取工艺为:温度85℃、时间1.5 h和固液比1∶25,提取的纤维素纯度可达98.61%。采用TEMPO氧化与超声处理相结合,制备纳米纤维素;再以其为骨架,加入聚乙烯醇和钠基蒙脱土制备纤维素复合气凝胶(NMPC)。结果表明:与纤维素气凝胶(PC)相比,NMPC对亚甲基蓝(MB)的吸附量最高达265.84 mg/g。当应变为60%时,NMPC的应力是PC的2倍。钠基蒙脱土的加入改善了气凝胶的结构,不仅提高了气凝胶的吸附性能,还提升了其压缩力学性能。

To achieve high value-added utilization of apocynum venetum stalk,cellulose is extracted from apocynum venetum stalk using nitric acid/ethanol method.The process is optimized through single factor and orthogonal experiments,and the conditions are defines as follows:temperature 85℃,time 1.5 h,solid-liquid ratio 1∶25,the purity of the extracted cellulose is 98.61%.Then,the nanocellulose is prepared by combining TEMPO oxidation and ultrasonic treatment,cellulose composite aerogel(NMPC)is prepared by adding polyvinyl alcohol and sodium montmorillonite to nanocellulose as the skeleton.The results show that compared with cellulose aerogel(PC),the adsorption capacity of NMPC for Methylene Blue(MB)is 265.84 mg/g,and the stress of NMPC is twice that of PC when the strain is 60%.The addition of sodium montmorillonite not only improves the adsorption performance of aerogel,but also improves its compression mechanical properties.The loaded sodium montmorillonite can improve the structure of the aerogel.