Flat attractive substrate
As a reference system, M¨oddel et al. (2009, 2010, 2011) first studied the adsorption of a single polymer to a flat,
attractive substrate. Here we focused on a minimalistic coarse-grained bead-stick model of a linear polymer with fixed
bond length (normalized to unity) where three terms contribute to the energy:
E = 4
N−2
i=1
N
j=i+2
⎡⎢⎢⎢⎢⎢⎣
σ
ri j
12
−
σ
ri j
6
⎤⎥⎥⎥⎥⎥⎦
+
1
4
N−2
i=1
(1 − cos ϑi) + s
N
i=1
⎡⎢⎢⎢⎢⎢⎣
2
15
σs
zi
9
−
σs
zi
3
⎤⎥⎥⎥⎥⎥⎦
. (1)
The first two terms are the energy of a polymer in bulk that consists of the standard 12–6 Lennard-Jones (LJ) potential
and a (very) weak bending energy, where ri j denotes the distance between the monomers i and j and 0 ≤ ϑi ≤ π
the bending angle between adjacent bonds. The third term describes the interaction with a flat attractive substrate
in the xy-plane, where zi is the distance of the ith monomer to the surface, see Fig. 1(a). The specific form of the
interaction is obtained by following Steele (1973) in treating the substrate as a continuous medium and integrating