Nanoporous polystyrene prepared via the selective removal of the low Mwcomponent in polystyrene blends

Herein, we report a straightforward technique for the creation of nanoporous polystyrene (PS) films. By preparing PS blend samples with Mws of 600?000 and 600?g?mol-1followed by rinsing with n-heptane, the low Mwcomponent was dissolved and removed to afford a low-density network of high MwPS. Nanoscale pores are formed as a result of the miscibility and stability of the initial state. The resulting materials were characterized using ellipsometry, atomic force microscopy and scanning electron microscopy. Materials with an effective refractive index as low as 1.1 can be prepared using this approach. The effects of varying the size of the low Mwpolymer and the application of low friction surfaces prepared with the nanoporous samples were investigated.