High porosity polymer aerogels can be easily obtained by supercritical fluid extraction of the solvent included in a gel and since the first reports published by Pekala et al. many papers have focused on the preparation and the characterization of organic aerogels prepared in supercritical conditions. The first examples of polymeric aerogels were based on highly cross-linked polymers (mainly resorcinol-formaldehyde and melamine-formaldehyde aerogels), but polymeric aerogels can be also obtained by CO2 extraction of hydro and organo thermoreversible (also called physical) gels where the gel three-dimensional network is due to crystalline regions instead of covalent bonds. Of peculiar interest are the thermoversible gels in which the crystalline regions are constituted by co-crystalline phases with inclusion of low molecular guest molecules within a polymer host crystalline phase. In fact is has been observed with syndiotactic polystyrene (s-PS) and poly(2,6-dimethyl-1,4-phenylene)oxide (PPO) gels that solvent extraction in supercriticical conditions can lead to aerogels characterized by amorphous pores and crystalline nanopores (micro by IUPAC definition). The association of amorphous meso- and macropores and crystalline nanopores confers unique properties to this new type of material. In particular sorption studies of VOC from aqueous diluted solutions or from air at low vapor pressures have shown that these aerogels present the fast sorption kinetics typical for aerogels (due to the high porosity and the large pore size) and a high sorption capacity characteristic (due to the sorption of the organic molecules in the host nanopores of the crystalline phase). These sorption properties as well as their good handling characteristics makes these new materials particularly suitable as a sorption medium to remove traces of pollutants from water and air. In this contribution different aspects relative to the preparation, the crystalline structure, the morphology and the sorption properties of monolithic aerogels based on s-PS and PPO will be presented and discussed.