Abstract: The effects of penicillin potassium salt on the cmc,the aggregation numbers and the diffusion coefficients of CTAB micelles have been studied.Addition of penicillin potassium salt increases the first cmc and the second cmc,decreases the aggregation numbers of micelles and increases the diffusion coefficient when CTAB concentration is between the first cmc and the second cmc. However,when CTAB concentration is higher than the second cmc,addition of penicillin potassium salt increases the aggregation numbers but decreases the diffusion coefficient.

Key words: CTAB, Aggregation number, cmc, Diffusion coefficient, Penicillin potassium salt