Nanoporous polymer crystals with cavities and channels

A cheap, commercial and easy-to-process hydrocarbon polymer (syndiotactic polystyrene, s-PS) can be crystallized in two different nanoporous phases (delta and epsilon) that show large uptake of several guest molecules and hence are suitable for applications in chemical separations and air/water purification as well as in sensorics. The recently discovered epsilon phase of s-PS is characterized by channel-shaped cavities crossing the unit cells along the c axis, rather than by isolated cavities as observed for the already known delta phase. Guest sorption from the delta and epsilon nanoporous phases eventually leads to two different classes of polymer co-crystals, where planar guest molecules present their planes roughly perpendicular and parallel to the polymer chain axes. The epsilon phase channels allow co-crystal formation with guest molecules much longer than the chain axis periodicity and, due to possible reactions between guest molecules, open the possibility to achieve new hybrid materials.