초록
Binding behavior of two cationic surfactants, dodecyltrimethylammonium bormide (DTAB) and tetradecyltrimethylammonium bromide(TTAB), to the chitosan-based polyelectrolyte was studied. Chitosan films used in this study were crosslinked with epichlorohydrin (ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results are represented by using the sequence generating function(SGF) method. The results of binding isotherm indicated that there is comparatively low cooperativity. The effect of salts(NaCl, $MgCl_{2}$) n the binding isotherms was also studied. The addition of salts in the polyelectrolyte/surfactant system resulted in a shift of the binding to higher free surfactant concentration because the polymer charge was screened by the counterion. The swelling ratio of the crosslinked chitosan was found to increase with increasing degree of deacetylation(DD) and with decreasing crosslink density of chitosan. A conformational phase transition of the crosslinked chitosan gels, as the binding with DTAB and TTAB proceeded, has been investigated.