side-chain (one being a conjugated π-system, the other an alkyl chain) means that changing the substrate to favour interactions with either one or the other should enhance either the face-on (strong backbone-substrate interactions) or side-on (strong sidechain-substrate interactions) orientations at the substrate interface. Although we do not consider any molecules with sidechains here, the impact of side-chains can be approximated in the coarse-grained modelling framework used in this work by considering their effect on the overall fluid-substrate interactions: a substrate that is more strongly attracted to the side-chains (particle side) will energetically favour the side-on orientation. This behaviour has been observed experimentally, for example though treatment of a substrate with a self-assembled monolayer of octadecyltrichlorosilane (OTS).