催化和机械辅助柠檬酸水解法高得率制备纤维素纳米晶体

High-yield Preparation of Cellulose Nanocrystals by Citric Acid Hydrolysis Combined with Catalyst and Mechanical Assistance

关键词:  柠檬酸  氯化铁  微射流  纤维素纳米晶体  清洁制备

Key Words:citric acid  ferric chloride  micro fluidization  CNC  cleaner production

摘要:以漂白蔗渣浆为原料，氯化铁为催化剂，通过短时微射流辅助柠檬酸水解法高得率制备了具有高羧基含量的纤维素纳米晶体（CNC）。研究发现，氯化铁的加入明显提高了CNC的制备效率，最优条件下得率可达60.2%；同时明显减小了纤维尺寸（119~507 nm）、提高了产物表面羧基含量（1.01 mmol/g CNC）和结晶度（74.7%）；制备的CNC具有良好的耐热性和分散稳定性。此外，预处理有效降低了后续CNC制备的机械能耗，且药品回收率高于89%。

Abstract:High-yield cellulose nanocrystals （CNC） with high carboxyl group content were prepared from bleached sugarcane bagasse pulp， by citric acid hydrolysis， using ferric chloride as catalyst， with assistance of short-time micro fluidization. The results showed that addition of ferric chloride significantly improved the CNC yield of 60.2%. With addition of ferric chloride， the size of the CNC （119~507 nm） was significantly reduced， the carboxyl content and crystallinity were both increased to 1.01 mmol/g CNC and 74.7%， respectively. Prepared CNC had good thermal stability and dispersion stability. Moreover， mechanical energy consumption was effectively reduced due to acid hydrolysis pretreatment， and chemicals could be recycled with a recovery rate higher than 89%.