Event
Bioengineering Seminar Series: Edward Barry
Monday, May 2, 2011
11:00 a.m.
Room 1200, Jeong H. Kim Engineering Building
Professor Helim Aranda-Espinoza
helim@umd.edu
Self-Assembly of Membranes and the Influence of Chirality
Edward Barry
Department of Physics
Brandeis University
Elucidating pathways for the assembly of nanostructured materials remains an important task both of fundamental scientific interest and in materials based applications. In this talk, I will outline a relatively new assembly pathway for such materials using simple mixtures of nanometer sized homogeneous hard rods and depleting polymer. The polymer acts to introduce an effective attraction between the otherwise entirely repulsive rods, and drives their self-assembly into a wide variety of equilibrium structures such as monolayer membranes and helical ribbons. Membranes, which are roughly 4 to 5 orders of magnitude larger than the constituent molecules themselves, have properties that are identical to lipid bilayers and can be investigated simultaneously at the molecular and continuum lengthscales. By systematical varying the aspect ratio, flexibility, and chirality of the constituent molecules, I will discuss how the various assembly pathways and macroscopic properties respond. In particular, by tuning the strength of chiral interactions, I will demonstrate a transformation into helical ribbons that can in turn lead to the assembly of double helices and other associated structures which can then be manipulated and sculpted using external forces.
