Equilibrium Dialysis Studies on the Interaction of some Surfactants with Poly(N-vinyl-2-pyrrolidone) and Bovine Serum Albumin

Inter-molecular interactions of sodium dodecylbenzene sulphonate (SDBS) and cetyl-trimethyl ammonium bromide (CTAB) with poly-(N-vinyl-2-pyrrolidone) (PVP) and bovine serum albumin (BSA) have been studied at 308.15K from equilibrium dialysis measurements. The process of binding of SDBS with PVP is found to complete through three distinct stages marked as (i) a weak interaction region, (ii) a strong co¬operative binding region and (iii) a no binding region. Stronger interaction of anionic surfactant (SDBS) with BSA compared to DTAB, suggests the existence of positively charged binding sites at PVP molecule. The observed surfactant-polymer binding data have been analysed in the light of various theoretical models for ligand-¬macromolecule interactions. The surfactant molecules bind with the macromolecule as monomer, in a co-operative manner.