Brown University

Geometry and Mechanics of Self-Assembled Colloidal Membranes

Description

Abstract:
Colloidal membranes are an example of a novel bioinspired soft material with rich properties that stem from the interplay of geometry and molecular order. A colloidal membrane is a two-dimensional monolayer composed of colloidal particles--in this case, rod-shaped viruses roughly 1 micron long and 6 nm in diameter--that are bound by entropic depletion forces. Because of their relatively large (micron) size, these membranes can be manipulated directly in the laboratory, offering a promising avenue to study other similar systems of biological importance such as lipid bilayer membranes or the endoplasmic reticulum. Perhaps the most notable feature of these colloidal membranes is their propensity to bend into exotic shapes such as saddles, unduloids, helicoidal ribbons, and closed vesicles under appropriate conditions. Strikingly, many of these shapes have zero mean curvature and/or negative Gaussian curvature, which contrasts with the case for other commonly encountered membranes and materials. Using a combination of theory and experiments, we put forth a minimal model based only on geometric quantities|such as length, curvature, and geodesic torsion to describe these phases mathematically and characterize the conditions under which they appear. Our effective model is most valid when the twist penetration depth of the membrane is much smaller than the membrane length scale|if this is the case, then it provides a way to describe membrane configurations without resorting to calculation of the cumbersome full liquid crystal energy.
Notes:
Thesis (Ph. D.)--Brown University, 2018

Access Conditions

Rights
In Copyright
Restrictions on Use
Collection is open for research.

Citation

Jia, Leroy, "Geometry and Mechanics of Self-Assembled Colloidal Membranes" (2018). Applied Mathematics Theses and Dissertations. Brown Digital Repository. Brown University Library. https://doi.org/10.26300/0gc4-c598

Relations

Collection: