Effect of Nonsolvent on the Liquid Crystalline Formation and Rheological Behavior of Microcrystalline Cellulose in Ionic Liquid System

Abstract

The effect of increasing water content on the liquid crystalline (LC) gel formation and rheological behavior of ternary microcrystalline cellulose (MCC)/1-Ethyl-3-methylimidazolium acetate (EmimOAc)/water system were investigated by using polarized optical microscope (POM) and rheological measurements. POM measurements indicated that the critical water content range for the formation of the fully anisotropic LC gel for 14 wt% MCC is from 4 to 10 wt%. As increase of the water content, the viscoelastic behavior is completely changed due to structural changes in ternary system. Increasing water content from 2 to 10 wt% led to an increase in the complex viscosity and both of moduli (storage modulus (Gʹ) and loss modulus (Gʺ)) of the ternary system. This may be due to enhance intermolecular interactions between cellulose chains by self-associated interaction.