Effect of solvent exchange on the supramolecular structure, the molecular mobility and the dissolution behavior of cellulose in LiCl/DMAc.
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 (1)H 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 (13)C 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.
Ishii
Daisuke
D
Division of Forest and Biomaterial Science, Graduate School of Agriculture, Kyoto University, Kitashirakawa Oiwake cho, Sakyo-ku, Kyoto, Japan.
Tatsumi
Daisuke
D
Matsumoto
Takayoshi
T
D000081:Acetamides / Q000737:chemistry*; D000096:Acetone / Q000737:chemistry; D000465:Algorithms; D002482:Cellulose / Q000737:chemistry*; D006860:Hydrogen Bonding; D018021:Lithium Chloride / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D053838:Scattering, Small Angle; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
D000081:Acetamides; D012997:Solvents; D000096:Acetone; D002482:Cellulose; D018021:Lithium Chloride; C013959:dimethylacetamide