Aggregate formation and surface activity property of an amphiphilic derivative of chitosan

A new kind of amphiphilic derivatives of chitosan, (2-hydroxyl-3-dodecanoxyl) propyl-carboxymethyl-chitosans (HDP-CMCHS) has been synthesised with different degrees of substitution (DS) of dodectyl glycidol ether (DGE). The plots of I1/I3 (the intensity ratio of pyrene emission at 374 and 385 nm) and of surface tension as a function of concentrations are combined to verify the aggregation formation and surface activity property of HDP-CMCHS. The results show that HDP-CMCHS can concentrate on the surface to decrease the surface tension, and can associate with hydrophobic chains to form aggregates in the solution. Increase of DS and addition of NaCl to the HDP-CMCHS solution leads to the surface tension decrease and the aggregation formation at lower concentration.