imeric cationic gemini surfactant, alkanediyl-a, w-bis (dimethyltetradecylammonium bromide) (referred to as 14—s-14, where (s = 4,5,6) using spectrophotometer at 70 °C and pH =5.0. The reaction follows first- and fractional-order kinetics, respectively.The reaction between ninhydrin and Gly-Ala was enhanced more effectively in presence of 14—s-14, dimeric surfactants than their single chain-single head counterpart tetramethylammonium bromide (TTAB) micelles. Also, whereas typical rate constant (k,,) increases and leveling-off regions, just likeTTAB, are observed with gemini, the later produce a third region of increasing kg, at higher concentration. Quantitative kinetic analysis of k 14—s-14 data has been established on the basis of pseudo-phase model.The micellar binding constants Ks for Gly-Ala and Kt, for ninhydrin were evaluated.
تاريخ النشر
29/11/2013
الناشر
CLRI-The XVI National conference on surfactants, emulsions and bio-colloids