2024 AIChE Annual Meeting
(462f) Analysis of Pearling, Buckling, and Wrinkling Stability of Cylindrical Multicomponent Vesicles
Authors
Venkatesh, A. - Presenter, Purdue University
Bhargava, A., Purdue University
Narsimhan, V., Purdue University
Break-up of complex cylindrical fluid threads has been a problem of interest for fluid mechanicians over the last century. These phenomena are seen in academic and industrially relevant processes involving surfactants, non-Newtonian fluids, and biomolecules. More importantly, pearling, buckling, and wrinkling phenomena of lipid vesicles are important to understand the mechanical behavior of cell membranes and other organelles. These vesicles are made up of multiple phospholipids and cholesterol molecules distributed on the membrane surface that give rise to inhomogeneous bending resistances. Tubular vesicles can undergo pearling – formation of beads on the liquid threads akin to the Rayleigh Plateau instability. Previous studies have inspected the effects of surface tension on the pearling instabilities of vesicles made up of homogenous phospholipids. However, not much has been discussed about the instabilities in multicomponent vesicles which involve an additional factor, phase separation and domain line tension. In this study, we inspect the linear stability of a cylindrical vesicle with multiple phospholipids on the surface undergoing phase separation and diffusion. We solve the Stokes equations along with the Cahn-Hilliard equations to develop a set of linearized dynamic equations governing the shape and concentration fields. We delineate the effects of phase separation on pearling and how it aids the process depending on the underlying critical dimensionless variables. We determine the conditions under which axisymmetric and non-axisymmetric modes are dominant, and supplement our results with an energy analysis that shows the sources for these instabilities. This study could be instrumental in understanding a multitude of physical phenomena surrounding cells, organelles, and even active fibers.
Preprint: Venkatesh, A., Bhargava, A., & Narsimhan, V. (2024). Linear stability of cylindrical, multicomponent vesicles. arXiv preprint arXiv:2402.19297.