Liquid Crystalline Behaviour of Chitosan in Formic, Acetic, Monochloroacetic Acid Solutions


Article Preview

The objective of this work was to prepare polysaccharide-based gels exhibiting liquid crystalline properties. Such systems may be used in some optical or in biomedical applications, where biodegradability is required. Chitosan is a derivative of chitin, widely used in a series of medical applications. Due to its rigid structure, chitosan or its derivatives may show lyotropic mesophases in certain conditions. In this work, chitosan solutions were prepared by mixing completely the polysaccharide with different concentration of formic, acetic and monochloroacetic acids at room temperature. X-ray diffraction patterns of the gels did not show the existence of a crystalline structure. Finger-prints texture observed by polarised optical microscopy was attributed to a cholesteric liquid crystalline phase that usually develops in concentrated solutions. Values of the nematic chiral pitch (P) were determined in function of acid solution concentration. The critical concentrations (C*) to form a lyotropic liquid crystalline phase in formic, acetic and monochloroacetic acids were determined, and the obtained values were confronted with the expected critical concentration based on the Flory formalism. The critical concentration values were found to be dependent upon the acid used.



Materials Science Forum (Volumes 514-516)

Edited by:

Paula Maria Vilarinho




M. Prabaharan et al., "Liquid Crystalline Behaviour of Chitosan in Formic, Acetic, Monochloroacetic Acid Solutions", Materials Science Forum, Vols. 514-516, pp. 1010-1014, 2006

Online since:

May 2006




[1] M. N. V. Ravikumar: React. Funct. Polym Vol. 46 (2000), p.1.

[2] M. Prabaharan and J. F. Mano: Drug Delivery Vol. 12 (2005), p.41.

[3] W. Y. Chuang, T. H. Young, C. H. Yao and W. Y. Chiu: Biomaterials Vol. 20 (1999), p.1479.

[4] M. Rinaudo and A. Dotard, Chitin and chitosan (Elsevier Applied Science, London 1989).

[5] I. Uematsu and Y. Uematsu: Adv. Polym. Sci. Vol. 59 (1984), p.37.

[6] J. D. Bernal and I. J. Fankuchen: Gen. Physiol. Vol. 25 (1941), p.111.

[7] Y. M. Yevdokimv, S. G. Skuridin and V. L. Salyanov: Liq. Cryst. Vol. 3 (1988), p.1443.

[8] C. Robinson: Tetrahedron Vol. 13 (1961), p.219.

[9] S. W. Fuller, M. H. F. Wilkins and G. L. Brown: Nature Vol. 194 (1962), p.1014.

[10] E. Iizuka: Polym. J. Vol. 9 (1977), p.173.

[11] D. G. Gray: Appl. Polym. Symp. Vol. 37 (1983), p.179.

[12] M. H. Godinho, J. G. Fonseca, A. C. Ribeiro, L. V. Melo and P. Brogueira: Macromolecules Vol. 35 (2002), p.5932.

[13] K. Ogura, T. Kanamoto, T. Sannan, K. Tanaka and Y. Iwakura: 2nd Chitin chitosan proceeding International Conference (Tottori, Japan 1982).

[14] M. Terbojevich, A. Cosani, G. Conio, E. Marsano and E. Bianchi: Carbohydr. Res. Vol. 209 (1991), p.251.


[15] D. K. Rout, S. K. Pulapura and R. A. Gross: Macromolecules Vol. 26 (1993), p.5999.

[16] D. K. Rout, S. K. Pulapura and R. A. Gross: Macromolecules Vol. 26 (1993), p.6007.

[17] D. K. Rout, S. P. Barman, S. K. Pulapura and R. A. Gross: Macromolecules Vol. 27 (1994), p.2945.

[18] Y. Dong, Y. Wu, J. Wang and M. Wang: Eur. Polym. J. Vol. 37 (2001), p.1713.

[19] Y. Wu, Y. Dong, L. Chen, J. Huang and J. Li: Macromol. Biosci. Vol. 2 (2002), p.131.

[20] Y. Dong, H. Wang, W. Zheng, Y. Zhao, D. Bi, L. Zhao and X. Li : Carbohydr. Polym. Vol. 57 (2004), p.235.

[21] Y. Dong, Q. Yuan, Y. Wu and M. Wang: J. Appl. Polym. Sci. Vol. 76 (2000), p. (2057).

[22] D. J. S. Hulmes: J. Struct. Biol. Vol. 137 (2002), p.2.

[23] P. J. Flory: Proc. Royal Soc. London, Ser. A Vol. 234 (1956), p.60.

[24] R. M. Silva, C. Elvira, J. F. Mano, J. San Román and R. L. Reis: J. Mat. Sci. Mater. Med. Vol. 15 (2004), p.523.

[25] C. Robinson, J. C. Ward and R. B. Beevers: Discuss Faraday Soc. Vol. 25 (1958), p.29.

[26] Y. Onagi, J. White and J. Feller: J. Polym. Sci. Polym. Phys. Ed. Vol. 18 (1980), p.663.