Abstract
The aggregation of the mixture of anionic surfactant - sodium dodecyl sulfate (SDS), and an anionic dye - bromocresol green sodium salt (BCG) was investigated by conductometric technique in water and alcoholic/diolic media within a temperature range of 300.55-320.55 K (with 5 K interval). The observed critical micelle concentration (cmc) decreases with surging of the concentration of BCG, following the same trend for β value. In presence of additives (ethanol, propanol, and ethylene glycol), the cmc value decreases up to a certain concentration and then the cmc values start enhancing with increasing concentration in all the cases. With the increased additive percentage, the β values continually decrease. Again, the cmc value increases gradually with the increase of temperature both in water and aq. additives media. The free energy of studied aggregation phenomena is negative which experiences an augmentation with the escalation of temperature. The increased negative value of free energy at elevated temperature indicates that the process becomes more spontaneous at a higher temperature. The
and
values reveal that the probable interaction forces between BCG and SDS are hydrophobic, ion-ion, as well as electrostatic interactions.