A CATIONIC SURFACTANT IS BOUND TO POLY(VINYLPYRROLIDONE) IN HIGH PH MEDIA

Interaction of tetradecylpyridinium bromide with poly(vinylpyrrolidone ) was studied by use of an electrode sensitive to the cationic surfact ant. In a neutral medium, there was no sign of interaction: potentiome tric titration response was in agreement with Nernst equation irrespec tive of absence and presence of the polymer. But in a medium with pH 1 1.3, deviation from Nernst response appeared in a PVP solution showing binding of the cationic surfactant onto the polymer which had been th ought indifferent to cationic surfactants in spite of strong affinity to anionic surfactants. The result is interpreted in terms of deproton ation from PVP at higher pH media.