Random Pinning and Wetting of Polymers

Abstract

In this chapter we look at pinning and wetting of a polymer by a random substrate. To that end, we think of the substrate as being composed of different types of atoms or molecules, occurring in a random order, and each time the polymer visits the substrate it picks up a reward or a penalty according to the type it encounters (see Fig. 11.1). Alternatively, we may think of a random copolymer consisting of different types of monomers, which interact differently with a homogeneous substrate. We will again be focusing on the phase transition between a localized phase and a delocalized phase. The results to be described below are an extension of those obtained for the homogeneous pinning model treated in Chapter 7.