A simple environment-friendly process for preparing high-concentration alkali lignin nanospheres
A simple environment-friendly process for preparing high-concentration alkali lignin nanospheres
复制标题
一种简单环保的高浓度碱木质素纳米球制备工艺
DOI：
10.1016/j.eurpolymj.2018.12.031
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发表时间：
2019-03-01
影响因子：
6
通讯作者：
Hou, Yi
中科院分区：
文献类型：
--
作者：
Liu, Chao;Li, Youming;Hou, Yi
基于芳环单体的生物质纳米材料在药物输送、催化和环境等领域具有广阔的应用前景。本文基于工业碱木质素在咪唑类离子液体中的有效溶解性，通过加入水作为反溶剂，快速制备了木质素纳米球。在3种咪唑类离子液体（1-戊基-3-甲基咪唑乙酸盐（C5 mim][Ac]）、1-丁基-3-甲基咪唑乙酸盐（[Bmim] [Ac]）和1-乙基-3-甲基咪唑乙酸盐（[Bmim] [Ac]））中，木质素均能较好地溶解，溶解率均大于25%，远高于其它有机溶剂。咪唑环中烷基链越长，木质素的溶解度越低。研究了木质素浓度、反溶剂添加速率、搅拌速率和pH值对木质素纳米球粒径的影响。结果表明，在适宜条件下制备的木质素纳米微球粒径在52-210 nm之间，稳定性良好，稳定性可达2个月以上。而且，与其他研究相比，纳米球的粒径要小得多，更容易控制。通过红外光谱（FT-IR）、凝胶渗透色谱（GPC）和紫外-可见光谱（UV-Vis）对木质素纳米球的性质进行了表征，发现木质素纳米球的分子量略低于原料碱木质素，且在离子液体制备过程中保留了木质素芳香环的主要结构。该方法简单、快速、环保，为木质素的高值化利用提供了一条高效可行的途径。
Biomass nanomaterials based on aromatic ring monomers have broad application prospects in the fields of drug delivery, catalysis and environment. In this paper, based on the effective dissolution of commercial alkali lignin in imidazole ionic liquids, lignin nanospheres were rapidly prepared by adding anti-solvent of water. In the three imidazole ionic liquids (1-amyl-3-methylimidazolium acetate (C5mim][Ac]), 1-butyl-3methylimidazolium acetate ([Bmim] [Ac]) and 1-ethyl-3-methylimidazolium acetate ([Emim] [Ac])), lignin can dissolve well, and the dissolution rates are all > 25%, which is much higher than other organic solvents. And the longer the alkyl chain in imidazole ring is, the lower the solubility of lignin is. The paper also studied the effects of lignin concentration, the addition rate of anti-solvent, stirring rate and pH on the size of lignin nanospheres. It was found that the lignin nanospheres prepared under suitable conditions have particle size in the range of 52-210 nm and have good stability for over two months. And, compared to other studied, the particle size of the nanospheres is much smaller and easier to control. Moreover, the quality of lignin nanospheres was elucidated by Fourier transform infrared spectroscopy (FT-IR), Gel permeation chromatography (GPC) and UV-vis spectroscopy (UV-Vis) measurements which found the molecular weight of lignin nanospheres was slightly lower the raw alkali lignin, and the main structure of the aromatic ring of lignin is preserved in the process of preparation of the nanospheres by ILs. The method of preparing lignin nanosphere from lignin-ionic liquids solution with water as anti-solvent is simple, rapid and environmentally friendly, and provides an efficient and feasible path for the high value utilization of lignin.