纳米纤维素晶须表面接枝及其液晶性能研究进展

作为一种新兴的纳米生物材料，纳米纤维素日益受到各界的广泛关注，对其进行表面接枝改性并开发新的功能是十分必要的。本文综述了纳米纤维素晶须表面接枝的技术及研究进展，主要介绍了传统自由基聚合、离子和开环聚合及活性自由基聚合技术，包括氮氧自由基调控活性聚合、原子转移自由基聚合、可逆加成-断裂链转移聚合、单电子转移活性自由基聚合，讨论了各种接枝聚合方法的适用范围和优缺点。简述了点击化学在纳米纤维素晶须表面接枝的应用。通过各种聚合方法改性得到的纳米纤维素晶须接枝共聚物往往具有一些特殊的功能，某些接枝共聚物在适当的溶剂中可以形成液晶态，本文重点介绍了接枝改性的纳米纤维素晶须的液晶性能及其形成机理和影响因素等。

Progress of surface grafted nano cellulose whiskers and their liquid crystals

Nano cellulose has received much attention as a new nano biomaterial.Surface grafting modification of nano cellulose is used to develop new functional nanomaterials.The surface grafting methods of nano cellulose whiskers(NCW) are reviewed,such as conventional free radical graft copolymerization,ionic and ring opening graft polymerization and living radical polymerization,which includes nitroxide-mediated polymerization(NMP),atom transfer radical polymerization(ATRP),reversible addition–fragmentation chain transfer polymerization(RAFT) and single electron transfer living radical polymerization(SET-LRP).The application of click chemistry in the surface grafting modification of NCW is summarized.The formation of lyotropic liquid crystal and thermotropic liquid crystal is also discussed.The formation mechanism and the factors affecting cholesteric liquid crystals of NCW are discussed.