SciELO - Scientific Electronic Library Online

 
 issue53Enzymatic production of ethyl esters from castor oilSynthesis of zeolite LTA from thermally treated kaolinite author indexsubject indexarticles search
Home Pagealphabetic serial listing  

Services on Demand

Article

Indicators

Related links

  • On index processCited by Google
  • Have no similar articlesSimilars in SciELO
  • On index processSimilars in Google

Share


Revista Facultad de Ingeniería Universidad de Antioquia

Print version ISSN 0120-6230

Abstract

GARTNER, Carmiña  and  LOPEZ, Betty Lucy. Stiffness of chitosan in solution through intrinsic viscosity measurem. Rev.fac.ing.univ. Antioquia [online]. 2010, n.53, pp.20-29. ISSN 0120-6230.

Chitosan is the partially deacetylated derivative from chitin. It is very significant to understand the behavior of chitosan as a polyelectrolyte, since most of chitosan final applications are related with its aqueous solutions. In this research, hydrodynamic parameters are studied for samples of chitosan with different degree of acetylation (DA) and molecular weight, to gain insight into the behavior of this polymer at different concentrations and ionic strengths (I). To achieve this, chitosan with an initial molecular weight of 226 kD and 30% DA, was depolymerized and deacetylated to obtain different molecular weights and DA. Relative viscosities were measured by rotational rheometry to caculate the overlap concentration (C*) and the entanglement concentration (Ce). These two concentrations allowed us to establish the dilute and concentrated solution regimes. Intrinsic viscosity ([η]) was measured for each sample in acetic acid 0,3 M solution using four levels of I. These measurements were used to calculate the salt tolerance factor (S) and the stiffness parameter (B). [η] measurements were also used to estimate Mark-Howink-Kuhn-Sakurada a factor, and statistical parameters such as the persistence length, the Kuhn length and the radius of gyration. These results provide an approximation to the conformation and stiffness of chitosan chains. It was found that variations in DA do not cause conformational changes, but modifications of molecular weight can dramatically transform the stiffness of the chain. These results will be used for optimizing the preparation of biocompatible membranes.

Keywords : Chitosan; stiffness; chain conformation; intrinsic viscosity; rheology.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )

 

Creative Commons License All the contents of this journal, except where otherwise noted, is licensed under a Creative Commons Attribution License