Valorization of lignin through an Understanding of the Structure and Properties of Lignin-based Carbon Nanofibres

木质素是地球上第二丰富的生物聚合物，具有作为一种低成本和可再生材料的潜力，可用于各种增值应用。在众多正在研究的木质素应用中，木质素基碳纤维(微米级碳纤维)是最有前途的产品之一。自20世纪60年代S以来，人们一直在研究木质素作为碳纤维(CF)前体的潜力。从那时起，人们报道了各种系统，利用干法、湿法或熔融纺丝方法制备不同类型的木质素和木质素/聚合物共混物，如木质素/聚丙烯腈(PAN)。根据品种(针叶、硬木或一年生纤维)、分离方法(硫酸盐、亚硫酸盐、苏打或其他生物精炼工艺)和纤维加工技术(湿/干/熔融纺丝、氧化、稳定化、碳化等)。各种基于木质素的前体和碳纤维已经被生产出来。然而，这些微米级纤维不能满足汽车结构应用的性能/成本要求。通过结合纳米纤维和木质素的优点，人们相信可以开发出一种新型的低成本混杂碳纤维和纤维组件，用于汽车、复合材料等结构应用和电磁屏蔽等功能应用。在这个项目中，我们计划研究以木质素、木质素/聚合物共混物及其木质素/纳米颗粒增强物为原料，通过静电纺丝工艺制备碳纳米纤维(CNF)的可行性。对木质素基碳纳米纤维(LCNF)的形态、力学、电学和电磁性能进行了表征，并对其在各种应用中的潜力进行了评估。该项目的成果将展示木质素基复合碳纳米纤维作为一种独特的工程材料的潜力，并因此为丰富的天然聚合物木质素的增值开辟了一条途径。

Lignin, the second most abundant biopolymer on earth, has the potential to serve as a low cost and renewable enabling material for a wide variety of value added applications. Of the numerous lignin applications under investigation, lignin-based carbon fibre (micron level LCFs) is one of the most promising products. Lignin has been under investigation for its potential as a carbon fibre (CF) precursor since the 1960's. Since that time a variety of systems have been reported utilizing dry, wet, or melt spinning of different types of lignin and lignin/polymer blends, such as lignin/polyacrylonitrile (PAN). Depending on the species (softwood, hardwood or annual fibre), method of isolation (Kraft, sulphite, soda or other biorefinery process), and fibre processing technology (wet/dry/melt spinning, oxidation, stabilization, carbonization, etc.) various lignin-based precursors and CFs have been produced. However these micron level fibres fail to meet the performance/cost requirements for automotive structural applications. By combining the advantages of nanofibres and lignin it is believed that a new class of low cost hybrid carbon fibre and fibrous assemblies can be developed for structural applications such as automobiles composites and functional applications such as electromagnetic shields. In this program we propose to study the feasibility of producing carbon nanofibre (CNF) from lignin, lignin/polymer blends, and their lignin/nanoparticle reinforcements by the electrospinning process. The morphological, mechanical, electrical, and electromagnetic properties of the lignin-based carbon nanofibres (LCNFs) will be characterized and their potential for various applications will be assessed. The outcome of this program will demonstrate the potential of lignin-based composite CNFs as a unique engineering material, and as a result, it will establish a pathway for adding value to the abundantly available natural polymer, lignin.