Effect of POSS Size on the Porosity and Adsorption Performance of Hybrid Porous Polymers

Polyhedral oligomeric silsesquioxanes (POSS), with unique cage-like three-dimensional (3D) structures, have been considered as promising nanoblocks for novel hybrid porous polymers (HPPs). To date, T8 POSS-based HPPs have been extensively studied, while the potential of larger POSS remains elusive and intriguing. Herein, we report the synthesis of a series of T8, T10, and T12 POSS-based HPPs (T8TPM, T10TPM, and T12TPM) and investigate their size-dictated structure-property relationships. These novel HPPs with identical composition yet distinct framework topologies are available through Friedel-Crafts polymerization of octa-, deca-, and dodeca-vinyl POSS with triptycene in a fixed mass ratio. It is found that the structures and properties of these materials are highly related to the POSS type and, more importantly, display an almost linear increase with increasing POSS size. Specifically, the surface area, pore volume, and adsorption capacity of T12TPM are 1214.8 m2 g-1, 1.00 cm3 g-1, and 4462.4 mg g-1 (Rhodamine B), showing an increase of 13.2, 56.3, and 37.9% compared with T8TPM, respectively. These results demonstrate the profound influence of the POSS size on the structure-property relationship of HPPs and could be used to predict the property of larger T14, T16, and T18 POSS-based HPPs. This calls for future endeavors in the exploration of larger POSSbased HPPs.