AN INFLUENCE OF THE SPATIAL ARRANGEMENT, LENGTH OF THE ALKYL CHAIN AND TEMPERATURE ON MICELLAR PROPERTIES OF (BENZYLOXY)CYCLOHEXYLMETHYL])-N,N-DIMETHYLAMMONIUM BROMIDES IN AQUEOUS-SOLUTIONS

In this work we study influence of the length of the alkyl chain and t emperature on critical micellar concentration (CMC) for cis and trans diastereoisomers of the N-alkyl-N-{[2-(benzyloxy)cyclohexylmethyl]}-N, N-dimethylammonium bromides in aqueous solutions using conductometric and spectrophotometric techniques. From the measured dependences, the degree of the counterion binding (beta) and thermodynamic parameters of micellization (Delta G(m)(0), Delta H-m(0), Delta S-m(0)) were calc ulated and compared with the literature data on similar compounds. The results show that lengthening of the alkyl chain by one methylene gro up causes approximately a two-fold reduction in CMC. The beta values d ecrease with temperature and with increasing length of the alkyl chain . While only a small decrease in the Delta G(m)(0) values (ca 1 kJ mol (-1)) due to increasing temperature was found, the decrease in Delta H -m(0) is much more pronounced.