ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 19, Number 5
JKCSEZ 19(5)
October 20, 1975 

According to the viscosity and density studies of an aqueous solution of dodecyl pyridinium chloride (DPC) it was shown that the 2nd critical micelle concentration (2nd cmc) existed in the solution in addition to the 1st cmc. The volume fraction ψm of the hydrated micelle was calculated by using the following equation: ηrm = 1 + 2.5ψm + 14.1ψm2 It has been found that the increment of ψm in the ψm vs. Cm curve decreased at near the 2nd cmc. And the partial specific volume (v) of DPC obtained from the density measurement also decreased rapidly at near the 2nd cmc and remains constant value above the 2nd cmc. This may be attributed to a change in the micelle structure at the 2nd cmc caused by a variation in the type of aggregation and by a decrease in the counterion binding by the micelle.