Interactions of poly(4-vinyl phenol) with hydrophobic ions in dispersion system

Interactions of poly(4-vinyl phenol) (P4VPh) with ionic surfactants (decyltrimethyl ammonium bromide (C10TAB), dodecyltrimethylammonium bromide (C12TAB), sodium 1-decanesulfonate (SDeSo) and sodium n-dodecyl sulfate (SDS)) and tetraalkylammonium (TAA) cations (as tetra-methyl ammonium chloride (TMACl), tetra-ethyl ammonium chloride (TEACl), tetra-butyl ammonium chloride (TBACl)) in the dispersion system were investigated by measuring the electrophoretic mobility (EPM) of P4VPh micro particles. The binding amounts of the ionic surfactants to P4VPh, which were estimated by the EPM values, increased with increasing temperature and the alkyl chain length of the respective cations. This result naturally means that the hydrophobic interaction played an important role on the binding. The binding amounts of cationic surfactants were higher than those of anionic ones. On the other hand, the temperature effect on the surfactants binding was more significant for the anionic surfactants than the cationic ones. These results suggest that some second interaction that exerts only for the cations and becomes unfavorable with increasing temperature, such as cation-π interaction, is also involved with the binding of the cationic surfactants. A similar binding behavior was observed for P4VPh–TBACl systems, while the binding amount was lower than those of the cationic surfactants. This finding means that the hydrophobic interaction involved with the P4VPh/TAA cations is weaker than that with the cationic surfactants.