ドデシル硫酸ナトリウム水溶液中でのポリビニルアルコールの固-液界面への吸着

The adsorption of polyvinyl alcohol(PVA) onto the surface of polyester and polypropylene fibers and ferric oxide particles from an aqueous solution of sodium dodecyl sulfate(SDS) was investigated by means of the interfacial tension and ζ-potential measurements. The surface tension of the aqueous solution of SDS was slightly increased by the addition of PVA into the solution. Wetting energies calculated from a contact angle measurement at SDS solution-fiber interfaces were decreased with an increase of the concentration of the added PVA. These results indecated that the surface activity of the aqueous solution of SDS was lowered in the presence of PVA. Zeta potentials of the fibers and the particles in the SDS solution containing PVA were less than that in the solution consisting of SDS alone. Moreover, the curves of the concentration of SDS～ζ-potential for the SDS solution containing PVA showed a minimum point in concentration renges below the critical micelle concentration of SDS. It was concluded that SDS and PVA carried out a competitive adsorption with each other onto the fiber and particle surfaces, and that the adsorbed PVA formed the thicker layer of polymer, in which the further adsorption of SDS caused from the solution, on the surfaces. On the other hand, in the SDS solution in the presence and absence of PVA, the deposition of the particles on the fiber surfaces was examined. The deposition amounts in the SDS solution containing PVA were less than in solution free from PVA. This effect of PVA to the particle deposition was correlated to the adsorption of PVA at the solutionsolid interfaces described above.