Dodecyl pyridinium chloride(DPC) 水溶液의 粘性度 및 密度硏究로 이 溶液에는 第一 cmc 外에 第二 cmc가 存在함을 알 수 있었다. 水化된 미셀의 부피分率${phi}_m$은 다음 式에 따라 算出하였다. ${Pi}_{rm}=1+2.5{phi}_m+14.1{phi}_m^2{cdot}{phi}_m-C_m$ 曲線에서 ${phi}_m$m의 增加率은 第二 cmc 近處에서 減少되고 또 密度測定으로부터 얻은 partial specific volume($={v}$)도 第二 cmc 近處에서 급격히 減少되고 그以上의 濃度에서는 一定値를 維持함을 알았다. 이것은 미셀의 集合型의 變化 및 미셀과 結合하고 있는 반대이온의 減少로 因한 第二 cmc에서의 미셀構造變化에 依한 것이라고 생각된다.
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 ${phi}_m$ of the hydrated micelle was calculated by using the following equation: ${Pi}_{rm}=1+2.5{phi}_m+14.1{phi}_m^2$ It has been found that the increment of ${phi}_m$ in the ${phi}_m$ vs. $C_m$ 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.
