School of Physics Soft Condensed Matter & Biophysics Seminar Series: Presenting Zheng D Cheng, Texas A&M University

Despite their natural abundance and wide industrial applications, such as red blood cells and clay, disks are the least studied colloidal systems compared to geometries like spheres and rods. We have established methods to fabricate and control the size, aspect ratio, and polydispersity of disks and systematically investigate their effects on discotic liquid crystal phase transitions. This talk will focus on surface controlled shape design of discotic microparticles using phase changing emulsions and the observation of the discotic smectic phase using nanoplates with identical thickness. Recent results such as discotic liquid crystals emulsions, gelation via ionic exchange, depletion attraction induced liquid crystal phase transition, iridescence from layered structure, and nematic hydrogels will briefly presented. Comprehensive understanding of the colloidal discotics in terms of complex fluids behaviors and liquid crystal transitions will help establish theory for model atomic liquid crystals and develop industrial applications.