交联型超双疏细菌纤维素复合气凝胶

Cross-linked Superamphiphobic Bacterial Cellulose Composite Aerogel

以细菌纤维素(BC)为原料,以柠檬酸(CA)为交联剂,次磷酸钠(SHP)为酯化交联催化剂,经液氮冷冻和冷冻干燥后得到BC复合气凝胶,熟化后采用低表面能氟硅烷进行化学气相沉积得到氟化BC复合气凝胶。接触角测试表明:交联型复合气凝胶与未交联复合气凝胶相比疏液性能显著提高;当CA添加量达到5%(wt)时,复合气凝胶对水、乙二醇、甘油、蓖麻油和十六烷的接触角均达到150°以上,对水和十六烷的接触角分别达到了164°和151°,实现了超双疏性能,进一步增加CA浓度对接触角无明显影响;扫描电镜(SEM)照片显示CA交联作用改善了BC复合气凝胶的纳/微多级粗糙结构,显著提高了气凝胶的疏液性能。

Composite bacterial cellulose(BC)aerogels were prepared via cross-linking by citric acid(CA)and subsequent freeze drying.Fluorinated BC composite aerogels were further obtained by chemical vapor deposition with low surface energy reagent of fluoroalkyl silane.Contact angle tests showed that the amphiphobic property of cross-linked composite aerogels was significantly improved when compared with the aerogels without cross-linking.When loaded with 5%(wt)CA,the composite aerogels possessed contact angles higher 150°for various liquids including water,ethylene glycol,glycerin,castor oil and hexadecane.The contact angles for water and hexadecane reached 164°and 151°,respectively,indicating that superamphiphobic performance was achieved.Increasing the CA concentration had little effect on the contact angles.SEM images showed that the cross-linking structure optimized the nano/micro hierarchical structures of BC composite aerogels,and further improved the superamphiphobic performance of the composite aerogels.