Dissipative particle dynamics simulation study on ATRP-brush modification of variably shaped surfaces and biopolymer adsorption

TL;DR

This study uses dissipative particle dynamics simulations to analyze how ATRP-brush modifications alter microparticle shapes and enhance biopolymer adsorption, with implications for surface functionalization and enzyme immobilization.

Contribution

It introduces a DPD simulation framework for analyzing shape changes and biopolymer adsorption on variously shaped ATRP-modified microparticles, including experimental validation.

Findings

ATRP-brush growth causes microparticle shape transformation.

Flat surfaces adsorb more biopolymers than curved ones at saturation.

Increased brush length and initiator concentration enhance biopolymer adsorption.

Abstract

We present a dissipative particle dynamics (DPD) simulation study on the surface modification of initiator embedded microparticles (MPs) of different shapes via atom transfer radical polymerization (ATRP) brush growth. The surface-initiated ATRP-brush growth leads to the formation of a more globular MP shape. We perform the comparative analysis of ATRP-brush growth on three different forms of particle surfaces: cup surface, spherical surface, and flat surface (rectangular/disk-shaped). First, we establish the chemical kinetics of the brush growth: the monomer conversion and the reaction rates. We next argue the structure changes (shape-modification) of brush-modified surfaces by computing the radial distribution function, spatial density distribution, radius of gyration, hydrodynamic radius, and shape factor. The polymer brush-modified particles are well known as the carrier materials for enzyme immobilization. Finally, we study the biopolymer adsorption on ATRP-brush modified particles in a compatible solution. In particular, we explore the effect of ATRP-brush length, biopolymer chain length, and concentration on the adsorption process. Our results illustrate the enhanced biopolymer adsorption with increased brush length, initiator concentration, and biopolymer concentration. Most importantly, the flat surface loads more biopolymers than the other two surfaces when adsorption reaches saturation. The experimental results verified the same, considering the disk-shaped flat surface particle, cup, and spherical particles.