Laser diagnostics of reverse microemulsions: Influence of the size and shape of reverse micelles on the Raman spectrum on the example of water/AOT/cyclohexane system

In this study, the influence of the size and shape of reverse micelles in water/AOT-Naicyclohexane microemulsions on the spectral characteristics of vibrational spectra was studied using Raman laser spectroscopy and method of dynamic light scattering. The sensitivity of the spectral bands of stretching vibrations of OH groups of water molecules and SO3 groups of AOT anions to the processes of self-organization of surfactants in microemulsions was established and explained. It is proposed to use this sensitivity of the OH and SO spectral bands of the Raman spectrum of microemulsions to create a method of determining the size of reverse micelles using Raman spectra. For this purpose, calibration curves of the spectral characteristics of these bands on the size of the reverse micelles were obtained. It was shown that the developed method can provide the best accuracy of determining the size of spherical reverse micelles 4.4%. The proposed method of laser diagnostics of microemulsions can also be applied to microemulsions with another composition. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

This study investigated the influence of the size and shape of reverse micelles in water/AOT-Naicyclohexane microemulsions on the vibrational spectral characteristics using Raman laser spectroscopy and dynamic light scattering. The sensitivity of OH and SO spectral bands to the self-organization of surfactants in microemulsions was established, proposing a method to determine the size of reverse micelles with high accuracy. The developed method is applicable to microemulsions with different compositions.