Polymerization of styrene in lyotropic liquid crystal lamellar (Lα) phase via gamma and electron beam irradiation

Abstract

Radiation induced polymerization in forming polystyrene of lyotropic liquid crystal lamellar (Lα) phase based on an Aerosol® OT (AOT)/sodium dodecyl sulfate (SDS), styrene, and deionized water ternary system has been investigated. Formed Lα phase, affirmed via polarized light microscope (PLM) through the visualization of a multi-layered structure with Maltese cross pattern, were irradiated in inducing polymerization at three different dose rates of gamma (γ) and an electron beam (EB) radiation. The phase behavior of pure Lα phase via rheology measurement deduced that the gamma irradiation dose of 7.2 kGy at a rate of 3.78 kGy/h had the most prominent effect on the elasticity and viscosity properties with respect to the sample storage modulus (G') and loss modulus (G") value. Whereby it was illustrated via scanning electron microscopy (SEM) micrographs that the phase structure copied upon polymerization had a layered phase morphology, templated as the Lα phase layered structure. The final yielded product was affirmed as polystyrene based on molecular conformation via Fourier transform infrared spectroscopy (FTIR) characterization. This study elucidates that styrene in a ternary system of Lα phase liquid crystal can undergo polymerization using gamma and electron beam radiation to produce polystyrene-template Lα phase structure that can be utilized as a layered structure with advantageous properties.