A mesoporous polymer bearing 3D-Triptycene, –OH and azo- functionalities: Reversible and efficient capture of carbon dioxide and iodine vapor

Coal-fired power plants are the highest contributors to global electricity generation. Flue gases from thermal power plants are rich in carbon dioxide. Thus, thermal plants also contribute substantially to the annual increase in the concentration of atmospheric CO₂ (greenhouse gas) which in turn leads to increased global warming and ocean acidification. Solutions to these problems are either capture of carbon dioxide from flue gas or exploring alternative sources of power generation such as nuclear energy. However, volatile radioactive byproducts produced in nuclear plants need to be arrested by a suitable adsorbent. Herein, for the first time, we report a triptycene-based hypercrosslinked porous polymer (TBHCP-OH) that contains CO₂-philic groups (–OH and –N[dbnd]N–). It was obtained using a simple Friedel–Crafts alkylation reaction. Mesoporous TBHCP-OH has high CO₂ capture capacity (87.6 mg/g) and excellent iodine vapor uptake capacity (2600 mg/g). This iodine uptake capacity is the highest among all triptycene based polymers reported till date. This may be attributed to the ample supramolecular interactions between arene/heteroatoms (O and N in TBHCP-OH) and iodine. The facile and simple synthesis of TBHCP-OH as well as its ability to efficiently capture pollutants renders it a promising material for environmental remediation.