脱水过程中纤维素纳米纤丝微观结构的研究

Study on the Microstructure of Cellulose Nanofibril During Dehydration

关键词:  纤维素纳米纤丝  脱水  再分散性  自组装

Key Words:cellulose nanofibril  dehydration  re-dispersibility  self-assembly

摘要:本研究首先制备了不同固含量的纤维素纳米纤丝（CNF），探究脱水程度对CNF再分散性的影响及其微观结构的变化。结果表明，由于CNF发生团聚并引起分子间/内氢键的重组，其再分散性受到影响。随脱水程度的增加，当CNF固含量由20.21%提高至41.88%时，Zeta电位迅速下降6.3 mV，其稳定性下降；当CNF固含量由2.38%提高至100%时，其透光率下降至43%，结晶度和晶粒尺寸分别提高50.31%和1.4倍，其再分散性降低。综合分析发现，CNF固含量控制在20%以下，对其微观结构和再分散性的影响较小。

Abstract:In this study， cellulose nanofibril （CNF） with different solid contents after thermal drying were used to investigate the effect of dehydration degree on the re-dispersibility of CNF and their microstructure changes. The results showed that the re-dispersibility of CNF was affected due to the agglomeration of CNF and causing reorganization of inter/intra molecular hydrogen bonds. With the increase of dehydration degree， when CNF solid content increased from 20.21% to 41.88%， the Zeta potential decreased by 6.3 mV， and its stability decreased. When CNF solid content increased from 2.38% to 100%， the transmittance decreased to 43%， the crystallinity and grain size increased by 50.31% and 1.4 times， respectively， whereas its re-dispersibility decreased. Comprehensive analysis found that the solid content of CNF was less than 20%， which had little effect on its microstructwre and re-dispersibility.