Adsorption of annealed branched polymers on curved surfaces

TL;DR

This study investigates how annealed branched polymers adsorb onto various curved surfaces, revealing effects of branching density and surface curvature on surface tension and polymer configuration.

Contribution

It introduces a mean field theoretical approach to analyze the adsorption behavior of branched polymers on curved surfaces, highlighting the influence of geometry and branching density.

Findings

Surface tension decreases with increased branching density.

Curvature influences the distribution of branch points and surface tension.

Optimal cavity radius minimizes surface tension for confined branched polymers.

Abstract

The behavior of annealed branched polymers near adsorbing surfaces plays a fundamental role in many biological and industrial processes. Most importantly single stranded RNA in solution tends to fold up and self-bind to form a highly branched structure. Using a mean field theory, we both perturbatively and numerically examine the adsorption of branched polymers on surfaces of several different geometries in a good solvent. Independent of the geometry of the wall, we observe that as branching density increases, surface tension decreases. However, we find a coupling between the branching density and curvature in that a further lowering of surface tension occurs when the wall curves towards the polymer, but the amount of lowering of surface tension decreases when the wall curves away from the polymer. We find that for branched polymers confined into spherical cavities, most of branch-points are located in the vicinity of the interior wall and the surface tension is minimized for a critical cavity radius. For branch polymers next to sinusoidal surfaces, we find that branch-points accumulate at the valleys while end-points on the peaks.