Mechanism of polymer particles formation during the soap-free emulsion terpolymerization of styrene - acrylic acid – N -(isopropyl acrylamide) for photonic crystals fabrication

Different morphologies of super-balls obtained to form photonic crystals of cholesteryl benzoate liquid crystals

The current study highlights the synthesis and characterization of some nanocomposite materials formed by polymer particles and liquid crystals. The liquid crystals used were cholesteryl benzoate (CLB), and the particles were synthesized by emulsion polymerization in the absence of the emulsifier. Through SEM and DLS analysis, the synthesis of particles of the same size was emphasized, and the amount of CLB showed no influence on these parameters. The lack of signal for CLB in the case of DSC and XRD analyses for the sample with the smallest amount of liquid crystal is attributed to the detection limits of the devices. To complete the surface characterization of the particles, XPS analysis was performed. Through XPS it was underlined that in the case of the smallest amount and the largest amount of CLB, respectively, it is encapsulated in the polymer particles, unlike the case of the average amount used, in which core-shell type morphologies have been obtained. For the electrical characterization of the samples, a Vector Network Analyzer (VNA) connected to two rectangular X-band (i.e., 8.2-12.4 GHz) waveguides through coaxial cables was used.