STUDIES ON THE INTERACTIONS BETWEEN ANIONIC SURFACTANTS AND POLYVINYLPYRROLIDONE - SURFACE-TENSION MEASUREMENT, C-13 NMR AND ESR

The interaction between anionic surfactants and polyvinylpyrrolidone ( PVP) are investigated using (CNMR)-C-13, ESR spectroscopy and surface tension measurements at the air/water interface. The behavior of singl e-chained surfactant, sodium dodecyl sulphonate (AS), is compared with that of the double-chained surfactant, sodium bis(2-ethylhexyl) phosp hate (NaDEHP). The results showed that a surfactant-polymer complex of ''necklace and head structure'' is formed in AS aqueous solutions in the presence of PVP due to the hydrophobic interaction between PVP and AS. The AS micelles nucleate on the polymer hydrophobic sites, and th e mobility of the AS head groups is not affected. But, for NaDEHP surf actant, it was found that PVP is little effective in influencing the m onomer-micelle equilibrium and no surfactant-polymer complex formed in the NaDEHP aqueous solution.