Adventures in Liquid Crystals

Research Interests:

Liquid crystals are a unique class of synthetic materials with tunable long-range orientations. Cooperative reorientation of liquid crystals (LCs) in response to subtle molecular-level changes at the interface with external stimuli provides amplified responses, which makes them promising materials for numerous industrial applications.

In the first year of my postdocoral work with Prof. Juan de Pablo at the University of Chicago, my research was focused on designing responsive and active interfaces using liquid crystals. Developing a simple set up, we demonstrated that liquid crystal interface is capable of reporting aggregation of polypeptides at lipid-aqueous interfaces at nanomolar concentrations, and therefore offers the potential for early diagnoses of neurodegenerative diseases. The results of this work was published at Advanced Functional Materials and appeared on the journal cover page.

Furthermore, in collaboration with the Argonne National Laboratory, we perform synchrotron X-ray reflectivity measurements to obtain structural information of liquid crystal molecules at the interface. Our experimental measurements are accompanied by an advanced theoretical and computational analysis.

In the second year, I have been exploring the topological defects in nematic liquid crystals induced by colloidal particles. Specifically, we have examined experimentally and theoretically, the effect of edge curvature of colloidal particles with homeotropic surface anchoring on their defect configuration and self-assembly. Our studies indicate that the edges sharpness modifies the defect structure, which can significantly affect the interaction between particles and their eventual self-assembly in the nematic liquid crystal.

Blue phase (BP) Liquid crystals are another class of nematic liquid crystals that I am interested in. In fact, BPs are nematic liquid crystals with high chirality that represent unique ordered defect structures over narrow range of temperature. Specifically, I study polymer stabilized blue phases. Using geometrical confinement and organic reagents, I have been able to obtain the blue phases at room temperature and expand the blue phase temperature range.

Although my research in the future will focus mainly on studying fundamental aspects of liquid crystalline materials and their potential applications in electronics and biomedical devices, studying the physics of the collective migration of epithelial and endothelial cells is another field which I am interested to pursue. After accomplishing my Ph.D. degree in polymer physics at ETH Zurich and before joining the de Pablo lab, I have had an opportunity to work on different projects at Harvard University with Prof. Jeffery Fredberg and use my expertise in Polymer Physics and Particle Image Velocimetry to investigate the basic physical processes underlie collective migration of epithelial and endothelial cells in confined geometries and stagnation points. From these works, I have authored and co-authored several manuscripts in high-impact peer-reviewed journals.

Teaching Interests:

With the background in polymer engineering from the Amirkabir University and Polymer Physics from ETH Zurich, I have strong foundation on materials science in particular polymer science related courses including polymer physics, polymer chemistry, crystallization, colloidal systems, rheology and polymer characterization.