Rajdeep Deb, featured ILCC liquid crystal artist, July 2011
Rajdeep Deb graduated from Assam University, India in 2002 and remained there for his post graduation followed by Ph.D. with Prof. Nandiraju V S Rao, during which he was engaged in the synthesis of intrinsically light generating bent core liquid crystals. The highlights of his work there include successful realization of novel four-ring bent-core liquid crystal exhibiting Sm phases with polarization splay modulated and layer undulated (PMLU) variants, B7 and B1. These compounds exhibit strong photoluminescence, the first family of SmCP phases to do so. He then joined Liquid crystal Material Research Center (LCMRC), University of Colorado at Boulder being ICAM-I2CAM Junior Exchange Awardee. There he studied the most spectacular defects and structures in B7 phases in Prof. Noel A Clark and Prof. Ivan I Smalyukh’s Lab. On his return, he joined National Institute of Technology, Silchar as a teaching assistant in Chemistry and was promoted to Lecturer in 2010. Dr. Deb has research interests in different aspects of materials science, central to which is an abiding passion for the design and synthesis of all different liquid crystal systems with novel molecular architecture.
The image points toward the complex nature of the structure of the B7 phase. Close inspection of the image display two types of textures of defects. In one, numerous flexible helical ribbons are observed, that nucleate in large quantities on cooling the samples from an isotropic phase. While growing if one helical nucleus meets another nucleus it may stop to grow, or might break and start to grow in another direction. These helical ribbons relax slowly with time to a variety of shapes one of which can be seen as flattened spindle like domain on left side of the image. The other shows shapes having the structure of developable domains quite like those observed in columnar phases, but one could see sharp periodicity across these domains. Jury comment: Crown jewels en miniature made of organic mesogens. One can melt them and rebuild them within minutes, in ever-changing beauty, with the turn of a knob of the temperature controller.