Porous Polymer Networks: Synthesis, Porosity, and Applications in Gas Storage/Separation

Three porous polymer networks (PPNs) have been synthesized by the homocoupling of tetrahedral monomers. Like other hyper-cross-linked polymer networks, these materials are insoluble in conventional solvents and exhibit high thermal and chemical stability. Their porosity was confirmed by N-2 sorption isotherms at 77 K. One of these materials, PPN-3, has a Langmuir surface area of 5323 m(2) g(-1). Their clean energy applications, especially in H-2: CH4, and CO2 storage, as well as CO2/CH4 separation, have been carefully investigated. Although PPN-1 has the highest gas affinity because of its smaller pore size, the maximal gas uptake capacity is directly proportional to their surface area. PPN-3 has the highest H2 uptake capacity among these three (4.28 wt %, 77 K). Although possessing the lowest surface area, PPN-1 shows the best CO2/CH4 selectivity among them.