Levich Institute Seminar Announcement, 03/16/2010
Tuesday, 03/16/2010
2:00 PM
Steinman Hall, Room #312
(Chemical Engineering Conference Room)

Professor Alejandro Rey
McGill University
Department of Chemical Engineering

"Liquid Crystal Models of Biological Materials and Processes"


ABSTRACT


Liquid crystal phases are found in DNA, proteins, lipids and polysaccharides. Frozen-in, chiral liquid crystal ordering also occurs in solid biocomposites such as insect cuticle, muscle, plant cell walls and collagen, where the helicoid structure is believed to arise by self-assembly processes. Spinning of silk fibers by spiders is another biological polymer process that relies on liquid crystal dynamic self-assembly. I will discuss the progress and challenges of modeling in three such applications:

(1) Characterization of structure and flow of liquid crystal collagen and DNA solutions. Theory and simulation based on liquid crystal flow, elasticity and interfacial models show how long range orientational order under flow conditions results in pattern formation processes that can be used to identify and characterize these materials.

(2) Biological helicoids form by directed self-assembly. Theory and computer simulation of chiral phase ordering show that the directed self-assembly process reproduces the natural structures. The computational results shed light on the role of chiral ordering on the formation of helicoidal monodomains.

(3) Spinning of spider silk involves a complex sequence of phase transitions that includes nematic phase ordering in the duct section of the spinning apparatus. Simulation of phase ordering under capillary con?nement replicates the observed structures found in Nephila clavipes and other orb-weavers. The computational results shed light on the role of defect textures in the fiber spinning process.

BRIEF ACADEMIC/EMPLOYMENT HISTORY

Alejandro Rey received his B.S. in Chemical Engineering from the City College of New York in 1985, where he was salutatorian of the college. He earned his Ph.D. In Chemical Engineering at the University of California, Berkeley under the supervision of Professor Morton Denn in 1988. Dr. Rey has been a faculty member at McGill University since 1988 and is now professor of Chemical Engineering and executive member of the McGill Advanced Materials Institute. He is a member of the McGill Center for Nonlinear Dynamics in Physiology and Medicine, the McGill Center for Self-Assembled Chemical Structures, and serves on the editorial boards of Soft Matter and Design and Nature. He has au­thored over 280 refereed papers and book chapters, and given over 90 invited talks. Professor Rey’s accomplishments have been recognized through several professional awards, including the 20th Olaf Hougen Professorship at the University of Wisconsin, the 2009 Cesar Milstein Fellowship, the James McGill Chair in Chemical Engineering, the 1993 Class of ‘51 Outstanding Teacher Award and the 2009 Research Excellence Award from McGill’s Faculty of Engineering.

RECENT RESEARCH INTERESTS

Soft Matter Science and Engineering, Computational Material Science, Interfacial Science, Biomimetics, Energy Storage.