Conductance values of sodium dodecyl sulphate and dodecyl trimethyl ammoniu
m bromide have been measured in aqueous and 2-propanol+water solutions. The
measurements are carried out at 298.15, 308.15 and 318.15 K. From conducti
vity data the val;es of critical micelle concentration and counterion assoc
iation constant (a) are determined. The observed thermodynamic data reveals
that micellisation process is favoured both energetically as veil as by en
tropy gain. LH NMR data of solutions indicate that whereas 2-propanol is so
lubilised in the interior of SDS micelles, the penetration of 2-propanol in
to DTAB micelles is comparatively weak.