Effect of solvent exchange on the supramolecular structure, the molecular mobility and the dissolution behavior of cellulose in LiCl/DMAc
Effect of solvent exchange on the supramolecular structure, the molecular mobility and the dissolution behavior of cellulose in LiCl/DMAc
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DOI：
10.1016/j.carres.2008.01.035
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发表时间：
2008-04-07
影响因子：
3.1
通讯作者：
Matsumoto, Takayoshi
中科院分区：
文献类型：
--
作者：
Ishii, Daisuke;Tatsumi, Daisuke;Matsumoto, Takayoshi
为了阐明纤维素在氯化锂/N，N-二甲基乙酰胺（LiCl/DMAc）体系中的溶解机理，研究了溶剂交换对纤维素分子超分子结构和分子运动性的影响.在以不同方式进行溶剂交换的纤维素中，DMAc处理的纤维素溶解最快。丙酮处理的纤维素的溶解比DMAc处理的纤维素慢得多，但比未处理的纤维素快得多。溶解行为的这种差异很好地解释了从小角X-射线散射分布计算的表面分形维数和H-1自旋晶格和自旋自旋弛豫时间估计从固态NMR光谱测量的差异。红外光谱和C-13自旋-晶格弛豫时间表明，DMAc在真空干燥后仍吸附在纤维素表面，并影响纤维素的分子运动性和氢键状态。(C)2008爱思唯尔有限公司保留所有权利。
We investigated the effect of solvent exchange on the supramolecular structure and the molecular mobility of the cellulose molecule to clarify the mechanism of the dissolution of cellulose in lithium chloride/N,N-dimethylacetamide (LiCl/DMAc). Among the celluloses that were solvent exchanged in different ways, the DMAc-treated celluloses dissolved most rapidly. Dissolution of the acetone-treated celluloses was much slower than the DMAc-treated ones, but considerably faster than the untreated one. Such differences in the dissolution behavior were well explained by the differences in the surface fractal dimension calculated from the small-angle X-ray scattering profiles and in the H-1 spin-lattice and spin-spin relaxation times estimated from the solid-state NMR spectroscopic measurements. Furthermore, it was suggested from the IR spectra and the C-13 spin-lattice relaxation times of cellulose that DMAc is adsorbed on the surface of cellulose even after vacuum-drying and affects the molecular mobility and hydrogen-bonding state of cellulose. (C) 2008 Elsevier Ltd. All rights reserved.