功能性无机-晶态纳米纤维素复合材料的研究进展与展望

Functional Inorganic-Cellulose Hybrid Nanocomposites

纤维素是自然界储藏量最大,可再生且可生物降解的生物高分子。晶态纳米纤维素是天然纤维素复合材料的结构支撑体,其多级孔道结构,手性液晶排列和活性羟基官能团赋予它优异的模板效应。本篇综述回顾了功能性无机-晶态纳米纤维素复合材料的研究进展。概述组装方法,侧重讨论静电纺丝法,细菌纤维素和纤维素气凝胶模板矿化法,凝胶-溶胶法,溶液浇铸法和静电层贴法的组装特点。扼要介绍了晶态纳米纤维素的形貌和晶体结构,提取方法,排列方式,化学修饰和溶剂等。天然复合材料的生物功能与其多级结构和多元组分的协同效应息息相关,文章以木质纤维素的刚性和海参表皮的化学感应性为例,浅谈晶态纳米纤维素微束的螺旋结构和纤维素复合体的多级结构在仿生组装功能性纤维素复合材料中的应用。最后,作者对晶态纳米纤维素在设计组装功能性复合材料领域的未来方向提出了一些设想,藉此综述抛砖引玉。

This paper provides an overview of the recent progress made in the area of functional inorganic-cellulose hybrid nanocomposites.The new advances reviewed are the use of nanocrystalline cellulose（NCC） as matrix materials to enhance the functionality of inorganic materials,as a biotemplating agent to generate nanocomposites with a hierarchical structure for improved functionality and the use of inorganic nanoparticles to generate functional inorganic-cellulose hybrid nanocomposites.An introduction into the methods used to assemble inorganic-cellulose hybrid nanocomposites is given with special attention to electrospinning method,templated mineralization via the structural feature,H-bonds network and the biosynthesis route of cellulose,sol-gel method,solution-casting method and layer-by-layer method.The types of NCC covered include those extracted from higher plants,tunicates and bacteria cellulose（BC）.An introduction into NCC covering general aspects of their preparation,crystal structures and morphology,arrangement and orientation under different conditions,chemical modification and solvents is made.Lignocellulose and sea cucumber dermis are fiber nanocomposites with a hierarchical structure.Their exceptional mechanical properties and intelligence are believed to be due to a functional adaptation of the structure at all levels of hierarchy.Selected bio-inspired cellulose nanocomposites are discussed to manifest how the hierarchical and helical feature of NCC can be used in smart materials design.A comprehensive coverage of the literature is given and the author＇s view on where the field is likely to advance in the future is highlighted.