Micellization Behavior of the 14-2-14 Gemini Surfactant with Some Conventional Surfactants at Different Temperatures

Mixed micellization behavior of the dimeric cationic surfactant ethanediyl-1,2-bis(dimethyl tetradecyl ammonium bromide) with monomeric cationic surfactants cetyltrimethyl ammonium bromide (CTAB), cetylpyridinium chloride (CPC), tetradecyl dimethyl benzyl ammonium chloride (C14BCl) and cetyl dimethyl benzyl ammonium chloride (C16BCl) was studied in aqueous and aqueous polyethylene glycol (PEG) solutions at various temperatures (298.15, 308.15 and 318.15 K) using conductometric and viscometric methods. The behavior of these mixed systems was analyzed in light of Rubingh's regular solution theory. The conductivity study indicates that the above systems behave nonideally with mutual synergism at 298.15 and 308.15 K, whereas antagonistic behavior is exhibited at 318.15 K. In the presence of PEG solution, various thermodynamic parameters associated with transfer of surfactant monomers from the medium consisting of polymer-free mixed micelles to polymer-bound mixed micelles like a dagger G (t) (o) , a dagger H (t) (o) and a dagger S (t) (o) at various temperatures were evaluated and discussed. The viscosity study shows that in aqueous solutions all these combinations exhibit significant negative departure in the relative viscosity (eta(r)) from the additivity rule at 298.15 and 308.15 K, whereas at 318.15 K these combinations (except in the case of C14BCl) follow the additivity rule. In presence of 5% PEG solution, all the combinations show positive departure from the additivity rule except the combination with C14BCl which shows negative departure at all the studied temperatures.