Interaction of a Zwitterionic Surfactant with Synthetic Clays in Aqueous Suspensions: A Multinuclear Magnetic Resonance Study

(1)H and (13)C NMR signal assignment of laurylamidopropylbetain has been obtained from 2D COSY, HETCOR, and HMBC pulse sequences. (13)C and (14)N NMR relaxation data show interaction of the polar head of the surfactant with low-charged clays dispersed in aqueous solution. The sodium cation exchange rate between the solid surface and the bulk is strongly affected by the charge of the clay layer, as seen from (23)Na NMR data. Such an exchange is also observed with clay suspended in sodium dodecyl sulfate solutions. Copyright 2001 Academic Press.