Physico-chemical properties of the association of cetyltrimethylammonium bromide and bovine serum albumin mixture in aqueous-organic mixed solvents.

Herein, we have investigated the association behavior of bovine serum albumin (BSA) and cetyltrimethylammonium bromide (CTAB) using the conductivity method in HO and HO + organic mixed solvents at different temperatures. The association phenomenon was detected from the deviation of the conductivity changes with enhancing the surfactant concentration and changes of numerous physico-chemical properties, such as CMC, α, β and thermodynamic variables (∆G, ∆H and ∆S). The values of CMC for the CTAB + BSA system in 10 % (v/v) solvents follow the trend: CMC < CMC < CMC < CMC < CMC. The interaction of BSA with CTAB is notably influenced due to a change of temperature and extent of hydration of BSA and surfactant. The obtained values of -∆G manifest that the association of BSA and CTAB mixture is a spontaneous process, while the values of -∆G in presence of 10 % (v/v) aq. organic solvents come out in the given sequence: -∆G (HO + DMSO) > ∆G (HO + DMF) > -∆G (HO + DX) > -∆G (HO + AN). The H-bonding, ion-dipole, along with the hydrophobic interactions, are believed to be the binding interactions between BSA and CTAB in the study media.