Solutions of cellulose in N,N-dimethylacetamide/lithium chloride studied by light scattering methods

The solution state of cellulose dissolved in the solvent system N,N-dimethylacetamide/lithium chloride (DMAc/LiCl) has been investigated by static and dynamic light scattering. Emphasis has been placed on the influence of the dissolution conditions, such as type of cellulose activation and concentrations of cellulose or LiCl, respectively. Dependent on these conditions, a molecular dispersion of cellulose molecules have been found in diluted solutions. Solutions with a high cellulose concentration (>2 wt%) and a low LiCl concentration (e.g. 6 wt%) have shown a noticeable amount of optically anisotropic particles, the properties of which have been determined by depolarized dynamic light scattering experiments. Dilution of such cellulose solutions did not result in a complete disintegration of these supermolecular structures.