Predicting Polymer Brush Behavior in Solvents using the Steepest-Entropy-Ascent Quantum Thermodynamic Framework

Abstract

The steepest-entropy-ascent quantum thermodynamic (SEAQT) framework is utilized to study the effects of temperature on polymer brushes. The brushes are represented by a discrete energy spectrum and energy degeneracies obtained through the Replica-Exchange Wang-Landau algorithm. The SEAQT equation of motion is applied to the density of states to establish a unique kinetic path from an initial thermodynamic state to a stable equilibrium state. The kinetic path describes the brush's evolution in state space as it interacts with a thermal reservoir. The predicted occupation probabilities along the kinetic path are used to determine expected thermodynamic and structural properties. The polymer density profile of a polystyrene brush in cyclohexane solvent is predicted using the equation of motion, and it agrees qualitatively with experimental density profiles. The Flory-Huggins parameter chosen to describe brush-solvent interactions affects the solvent distribution in the brush but has minimal impact on the polymer density profile. Three types of non-equilibrium kinetic paths with differing amounts of entropy production are considered: a heating path, a cooling path, and a heating-cooling path. Properties such as tortuosity, radius of gyration, brush density, solvent density, and brush chain conformations are calculated for each path.

37 pages, 19 figures

References in corpus (9)

• Scalable replica-exchange framework for Wang-Landau sampling
• Steepest Entropy Ascent Model for Far-Non-Equilibrium Thermodynamics. Unified Implementation of the Maximum Entropy Production Principle
• Optimal Modification Factor and Convergence of the Wang-Landau Algorithm
• Optimized Wang-Landau sampling of lattice polymers: Ground state search and folding thermodynamics of HP model proteins
• Decoherence predictions in a superconductive quantum device using the steepest-entropy-ascent quantum thermodynamics framework
• Loss-of-entanglement prediction of a controlled-PHASE gate in the framework of steepest-entropy-ascent quantum thermodynamics
• Predicting Non-Equilibrium Folding Behavior of Polymer Chains using the Steepest-Entropy-Ascent Quantum Thermodynamic Framework
• Entropy-Driven Microstructure Evolution Predicted with the Steepest-Entropy-Ascent Quantum Thermodynamic Framework
• Predicting Defect Stability and Annealing Kinetics in Two-Dimensional PtSe${}_2$ Using Steepest Entropy Ascent Quantum Thermodynamics