Heterogeneous binding of polymers on curved nanoparticles.

Abstract

Unraveling protracted polymer binding on curved surfaces of nanoparticles (NPs) is important for the fabrication of multifunctional nanostructures in cutting-edge research disciplines such as directional self-assembly and nanomedicine. By using our newly developed Integral of First-passage Times (IFS), we demonstrate a curvature-dependent heterogeneous binding of polymers on curved NPs, not only in terms of the binding dynamics but also in terms of the final adsorption densities. The highly curved surfaces on NPs can adsorb larger density polymers with binding kinetics that are faster than those on less curved areas, which is consistent with recent experimental observations. In particular, the spherical corners on cubic NPs with a radius of R = 3.0 nm can adsorb polymers at a density 4.1 times higher than those on planar surfaces and 1.7 times higher than those on rod edge surfaces. A unified relationship between adsorption densities and surface curvatures is proposed to collapse all the data onto one master curve. The findings demonstrate a heterogeneous binding of polymers on curved NPs, providing effective guidelines for the rational design of functional nanostructures in different applications.