Property Investigation of Pseudo Polyelectrolytes Self-Assembled From PVP/SDS By Viscometry

Relative viscosity of the system self-assembled by polyvinylpyrrolidone(PVP) and sodium dodecyl sulfate(SDS) was determined by Ubbelohde viscosity meter. Flow time of PVP aqueous solutions, SDS aqueous solutions and PVP/SDS complex solutions at different concentrations were seperately measured. The results showed that there existed two inflection points, critical aggregation concentration (CAC) and polymer saturation point (PSP), on the reduced viscosity - SDS concentration curve for the PVP / SDS complex system. It was also determined that CAC < CMC < PSP. The reduced viscosity of PVP / SDS solution increased dramatically with increasing SDS concentration which had reached CAC, and the higher the PVP / SDS concentration, the lower the viscosity of the system, presenting the same characteristics with polyelectrolytes. The potential of PVP / SDS system was negative determined by Zeta-potential. All of the results showed that the PVP / SDS complex system presented a supermolecular structure and was an anionic pseudo polyelectrolyte.