IRG Meetings


Each month the MRSEC holds Active Matter and Membrane talks. Everyone is invited to attend. The research goal of the MRSEC is to understand the emergence of biomimetic functionalities that are highly sought-after in materials science and to synergistically engineer life-like materials.

Chaitanya Joshi, Hagan Lab, Organizer
Greg Hoeprich, Goode Lab Postdoc, Organizer

Thurs., Oct 18
Title: Microphase Separation and Stability of Rafts in Colloidal Membranes
Chaitanya Joshi, Hagan Lab
Abstract: Despite being different in structure and thousands of times larger than lipid bilayers, colloidal membranes can be described by the same continuum theory. Their large size enables the study of behaviors that cannot be visualized in lipid bilayers. Colloidal membranes are an experimental system composed of rod-like chiral particles. A tunable depletion interaction drives the self-assembly of these rods into one-rod-length thick monolayers. Membranes formed from a mixture of short right-handed rods and long left-handed rods exhibit a microphase separation regime, wherein one rod species forms finite-sized domains, or rafts, floating in a background membrane of the other rod species. The short rods form right-handed rafts which have interactions mediated through the background membrane. We have a Ginzburg-Landau theory explaining the formation and interactions of these rafts. 
Recent experiments have studied how these rafts are affected upon tuning the background membrane chirality. This tuning can be achieved by having a mixture of two kinds of long rods that are of equal length but opposite handedness. It is found that lowering the background chirality this way allows the short rods to form both right-handed and metastable left-handed rafts. We are working towards a theory of microphase separation which accounts for the existence of these metastable rafts.
Abelson 229, 4PM

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