Polar Solvation Dynamics in Nonionic Reverse Micelles and Model Polymer Solutions

Abstract

The effect of confinement on solvation dynamics has been explored in Brij-30/cyclohexane and Triton X-100/cyclohexane nonionic reverse micelles. Inside the reverse micelles, the polar solvation dynamics become slower and show additional slow relaxation modes not observed for bulk water. The solvation dynamics inside the Triton X-100 reverse micelles is slower than the dynamics inside Brij-30 reverse micelles. The results for solvation dynamics in the reverse micelles contrast solvation dynamics in aqueous tri(ethylene glycol) monoethyl ether solutions comparable to the reverse micellar interiors, which show significantly faster response. Measurements in the nonionic reverse micelles are also compared to previous work on ionic reverse micelles. Results reported here show that the interactions of water with the polyoxyethylene ether, as well as the micellar confinement inside these reverse micelles, effectively immobilize the water in the micellar interiors.