Unraveling the Dynamics and Equilibrium Behavior of Pure and Mixed Micelles: Insights from Microscopic coarse-grain modeling

Identifier:  TDX:3997

Handle: https://hdl.handle.net/20.500.11797/TDX3997

Authors:  Pantelidou, Maria

Abstract:
This thesis focuses on exploring and controlling the mechanisms behind the formation and dynamic behavior of pure and mixed micelles, which are widely used across many industries. Single-Chain Mean-Field simulations of coarse-grain models are proposed as a quick and efficient way to explore these complex molecular systems. The thesis is divided into two parts, the first of which explores the dynamic behavior of micelles using time correlation functions and dynamic Single-Chain Mean-Field theory simulations. The results show that the exit of poloxamer copolymers from micelles exhibits four distinct regimes: a fast reorganization, a logarithmic intermediate regime, an exponential intermediate regime, and a final exponential decay. It was observed that the logarithmic response previously believed to be due to polydispersity can also arise from the degeneracy of energy states of the hydrophobic block in the micelle core. This finding suggests that the short-time dynamic response of these systems has an entropic origin rather than being influenced by polydispersity as previously thought. A modified Eyring equation was proposed to reproduce the observed dynamic behavior. The second section of the thesis delves into the examination of the equilibrium behavior of mixed micelles utilizing the Single-Chain Mean-Field method for binary systems