Despite these complications, the results indicate that it is difficult to obtain a face-on orientation under equilibrium conditions of isotropic bulk GB fluids for parameters representative of OSCs. For the systems studied here, the interaction energy favours the face-on orientation when the interaction strength is the most isotropic (κ = 0.7) of the values studied (Fig. ), though only marginally, and more significantly when κ is increased to > 1. In all cases, however, the entropic term (Fig. ) is sufficiently large that the overall free energy still predicts the side-on orientation. While significantly lowering the temperature would help to transition to the face-on orientation by reducing the entropic contri-bution, this is likely to result in a transition to a liquid-crystal or crystalline bulk phase. On the other hand, reducing the entropic component by reducing the shape anisotropy is likely to lead to a more isotropic interface orientation.