A Langevin dynamics approach for multi-layer mass transfer problems

TL;DR

This paper introduces a Langevin dynamics simulation method to model mass transfer across layered porous materials, accurately incorporating interfacial boundary conditions, demonstrated through a drug-eluting stent case study.

Contribution

It presents a novel Langevin dynamics approach with detailed implementation of the Kedem-Katchalsky boundary condition for layered diffusion problems.

Findings

Simulation results agree well with continuum diffusion solutions

The method effectively models complex interfacial mass transfer

Applicable to biomedical and porous media applications

Abstract

We use Langevin dynamics simulations to study the mass diffusion problem across two adjacent porous layers of different transport property. At the interface between the layers, we impose the Kedem-Katchalsky (KK) interfacial boundary condition that is well suited in a general situation. A detailed algorithm for the implementation of the KK interfacial condition in the Langevin dynamics framework is presented. As a case study, we consider a two-layer diffusion model of a drug-eluting stent. The simulation results are compared with those obtained from the solution of the corresponding continuum diffusion equation, and an excellent agreement is shown.