Investigation of the interactions of polyvinylpyrrolidone with mixtures ofanionic and nonionic surfactants or anionic and zwitterionic surfactants by pulsed field gradient NMR

The interaction of polyvinylpyrrolidone (PVP) with an anionic surfactant (s odium dodecyl sulfate, SDS), a nonionic surfactant (pentaethylene glycol mo nodecyl ether, C10E5), and a zwitterionic surfactant (lauryl amido propyl b etaine, LAPB) has been investigated by means of pulsed gradient spin-echo N MR (FT-PGSE NMR), allowing self-diffusion coefficients to be determined. Th e results confirm the strong interaction prevailing in the PVP/SDS system, whereas no association has been observed in the PVP/C10E5 and PVP/LAPB syst ems. Mixing PVP with two surfactants, namely SDS and C10E5 or SDS and LAPB, results in the formation of ternary aggregates between the polymer and the mixed micelles. (C) 2001 Academic Press.