Polymeric Photonic Crystals Containing 5CB Liquid Crystal: Synthesis and Characterization

The present study highlights the synthesis of a polymer nanocomposite obtained by soap-free emulsion polymerization in the presence of a liquid crystal (LC). The polymer used was styrene-acrylic acid (ST-AA), and the liquid crystal was 4-Cyano-4′-pentylbiphenyl (5CB). The motivation for this study lies in the excellent application prospects in widespread advanced technology fields for the obtained polymer-5CB colloids and the possibility of implementing the synthesis method for other types of LCs. The influence of varying 5CB concentrations on polymerization, specifically on the types and sizes of the particles generated, was investigated. The SEM analysis supports the DLS data, and the TEM investigation reveals the core–shell structures of the particles, exhibiting a “golf ball”-like microstructure. In all cases, photonic crystal structures are formed. It is notable that, in addition to particles containing liquid crystal, a photonic structure is also obtained, as highlighted by UV–vis and SEM. A mechanism for the polymerization and formation was proposed in correlation with the GPC results. Additionally, polarized optical microscopy revealed that the polymeric nanocomposite film exhibited birefringence.