Measurement of critical concentration for mesophase formation of chitosan derivatives in both aqueous and organic solutions
Date
2006-07Author
Dong, Yan-ming
董炎明
Mao, Wei
Wang, Hui-wu
Zhao, Ya-qing
Li, Xiao-jian
Bi, Dan-xia
Yang, Liu-lin
Ge, Qiang
Fang, Xueming
Collections
- 化学化工-已发表论文 [14235]
Abstract
A novel chitosan derivative, acryloyl chitosan (AcCs), and two N-maleoyl chitosans, MaCs-1 and MaCs-2, with different degrees of substitution were synthesized using completely deacetylated chitosan as raw material under different reaction conditions. AcCs is an amphiphilic chitosan derivative, but MaCs-1 and MaCs-2 are soluble in water and organic solvents respectively. The concentrated solutions of AcCs, MaCs-1 and MaCs-2 an demonstrated mesophases and were investigated using polarizing optical microscopy (POM). Circular dichroism (CD) was also employed for determining the critical concentration for mesophase formation. A broad peak in the visible light region of CD spectra had its origin in the appearance of the mesophase, and arose from the selective reflection of cholesteric helix pitches. The results of CD measurements agreed with those of POM. The critical concentration values for aqueous solutions were much lower than those for organic solutions, which was explained by the strong interactions between the chitosan derivatives and water. (C) 2006 Society of Chemical Industry.