Polymeric films with three different uniplanar crystalline phase orientations

Semicrystalline syndiotactic polystyrene (s-PS) films, for all crystalline phases based on helical chains (delta, gamma and clathrates), have been prepared with high degrees of three different kinds of uniplanar orientation. In particular, by suitable solution- or solvent-induced crystallizations, (010), (002), or (210) crystalline planes of the nanoporous delta and clathrate phases can be oriented preferentially parallel to the film plane. To our knowledge, the achievement for a given polymeric crystalline phase of high degrees of three different uniplanar orientations is unprecedented. This is particularly relevant for s-PS due to the functional properties of its nanoporous crystalline delta phase as well as of its clathrate phases. As for the clathrate phases, it is also worth noting that, since each cavity of the clathrate phase generally includes one isolated guest molecule whose mobility is generally low, the control of the orientation of the host crystalline phase also allows the control of the orientation of the guest molecules.