  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.
