Electron spin-lattice relaxation times of spin probes in aqueous dispersions of a unique amphiphilic compound obtained by a saturation recovery method

摘要

Electron spin-lattice relaxation times (T-1c) of a unique norlionic amphiphilic compound, (poly(oxyethylene) hydroGenated castor oil. HCO) in aqueous dispersions, were investigated by electron paramagnetic resonance (EPR) and saturation recovery (SR) spectroscopies. The spin probes, 5-doxylstearic acid (5-DSA) and 3 beta-doxyl-5 alpha-cllolestane (CHL). were used to obtain T-1e values for the head group region in the HCO membrane. Analysis of SR siganals from both probed, showed that the T-1e, value (approximate to 5 ps at 20 degrees C) indicates relatively faster relaxation behavior in the region than that of 12-DSA. No abrupt change (Such as phase transition) of the relaxation time was observed in the temperature region Studied Thus. the present T1, results indicate relative flexibility for both probe moieties in the membrane throl.l.ohout the temperatures studied.