Length dependence of crosslinker induced network formation of rods: a Monte Carlo study

Abstract

Self-assembling filament networks are of great relevance for the development of novel materials. They show interesting mechanical properties and have exceptionally large internal surface areas. We analyzed the percolation behavior of a self-assembling network of rigid filaments and crosslinkers with the help of Monte Carlo simulations. In the system, filaments are represented by long spherocylinders, while crosslinkers are mimicked by short spherocylinders with adhesive sites at both ends with which the crosslinkers can bind to the filaments. We had analyzed the dependence of the network structure on the filament volume fraction, the crosslinker–filament ratio, and the adhesion strength in a former article (Soft Matter, 2009, 5, 1504). In this work, we study the influence of the filament length on the percolation threshold, finding that, for a given filament volume fraction and crosslinker filament ratio, the percolation transition is rather independent of the filament length. We introduce an analytic approach, which reproduces the binding probability qualitatively.