# Coarse-graining strategy for modeling effective, highly diffusive fluids with reduced polydispersity: A dynamical study

## TL;DR

This paper introduces a coarse-graining method to simplify multi-component fluids into effective monodisperse systems, preserving key dynamic features and enabling easier experimental modeling of complex fluids.

## Contribution

A novel coarse-graining strategy that reduces polydispersity in fluid models while maintaining dynamic and structural properties, facilitating experimental realization.

## Key findings

- Effective monodisperse system mimics mixture dynamics
- Similar glass transition temperature and critical exponents
- Radial distribution function resembles original mixture

## Abstract

We present a coarse-graining strategy for reducing the number of particle species in mixtures to achieve a simpler system with higher diffusion while preserving the total particle number and characteristic dynamic features. As a system of application, we chose the bidisperse Lennard-Jones-like mixture discovered by Kob and Andersen [Phys. Rev. Lett. 73, 1376 (1994)] possessing a slow dynamics due to the fluid's multi-component character with its apparently unconventional choice for the pair potential of the type-A-type-B arrangement. We further established in a so-formed coarse-grained and temperature-independent monodisperse system an equilibrium structure with a radial distribution function resembling its mixture counterpart. This one-component system further possesses similar dynamic features like glass transition temperature and critical exponents while subjected to Newtonian mechanics. This strategy may finally lead to the manufacturing of new nanoparticle/colloidal fluids by experimentally modeling only the outcoming effective pair potential(s) and no other macroscopic quantity.