羧基化纤维素纳米纤丝对单片层蒙脱土分散性能的研究

Investigation on the Dispersion Properties of Carboxylated Cellulose Nanofibrils for Monolayer Montmorillonite

关键词:  纤维素纳米纤丝  蒙脱土  分散稳定性  羧基化

Key Words:cellulose nanofibril  montmorillonite  dispersion stability  carboxylation

摘要:本研究使用纤维素纳米纤丝（CNF）作为分散剂制备分散稳定的单片层蒙脱土（MMT）分散液，探究了CNF羧基含量和长径比对单片层MMT分散液的分散稳定性、平均粒径、黏度和得率的影响。结果表明，2,2,6,6-四甲基哌啶氮氧化物（TEMPO）氧化的CNF（TOCNF）对单片层MMT的分散性能优于羧甲基化CNF（CMCNF）。当羧基含量为1.24 mmol/g时，TOCNF展现出最佳的分散效果。此时，分散液中主要为单片层的MMT，其平均粒径为317 nm。进一步研究表明，当使用质量分数0.1%的TOCNF（1.24 mmol/g）为分散剂时，其分散MMT的最大初始质量分数为1.5%，此时，超声离心后的单片层MMT得率和质量分数分别为52%和0.78%。

Abstract:In this study， colloidally stable monolayer montmorillonite （MMT） dispersions were prepared using cellulose nanofibrils （CNF） as dispersant， and the effects of carboxyl content and aspect ratio of CNF on the dispersion stability， average particle size， viscosity， and yield of monolayer MMT dispersions were explored. The results showed that 2,2,6,6-tetramethylpiperidine nitride oxide （TEMPO） oxidized CNF （TOCNF） was more effective than carboxymethylated CNF （CMCNF） in dispersing monolayer MMT dispersions. Specifically， TOCNF with a carboxyl content of 1.24 mmol/g presented the best dispersion capability and the as-prepared monolayer MMT had an average particle size of 317 nm. Additionally， when the concentration of TOCNF （1.24 mmol/g） dispersion was 0.1%， the maximum initial concentration of the dispersed MMT was 1.5%， the yield and concentration of the monolayer MMT after ultrasonication and centrifugation were 52% and 0.78%， respectively.