Design, Synthesis And Characterization Of Novel Porous Aromatic Frameworks With Triazine Ring

Recent years, porous organic frameworks (POFs) have drawn extensive attentionwith ultralight skeletons, high surface area and superior properties. This work wascommitted to form PAFs with triazine and discussed the properties of PAFs. Thetriazine-PAFs with π-electron system and nitrogen-rich network offered the stronginteraction with CO2molecule. We use two different ways to construct PAFs withtriazine, we use nitriles self-polymerization to introduce triazine in chapter2and3,and select cyanuric chloride as triazine introducer to build-up PAFs.First, we choose tetrakis (4-cyanophenyl) silica (TCPSi) as a tetrahedral monomerand ZnCl2as solvent and catalyst to build-up PAF-16. Under argon, salt was grindedwith TCPSi and sealed as1,5,10salt/monomer molar ratio, then reacted in differenttemperatures to prepare PAF-16. We discussed the influence of salt/monomer molarratio and different temperatures, notarized the best reaction condition is400oC and10molar ratio. PAF-16was amorphous material, with high thermostability and solventstability and high surface area (1166m2g1), which leads to a better gas adsorptionproperties.Second, we compounded new monomer tetrakis (4-cyanodiphenyl) silica(TCDPSi) as tetrahedral block mixed with ZnCl2in glove box which filled with argonand then sealed in ampoule. PAF-51-1and PAF-51-2was obtained at reactiontemperature400oC and550oC, respectively. The BET surface areas were720m2g-1(PAF-51-1) and557m2g-1(PAF-51-2). Compared with CH4and N2, the CO2adsorption capacity of PAF-51is much better. The selectivity of PAF-51-2can reached52.2calculated from the initial slopes of the CO2and N2adsorption isotherms. TheCO2/CH4selectivity also reached10.3. This capability of PAF-52is believed to be very useful for decreasing the global warming effect and clean energy regeneration.PAF-52used the same synthetic method but different monomers as tetrakis(4-cyanodiphenyl) methane (TCDPM). The surface area reached1159m2g-1. Gaschromatography of PAF-52indicates that CO2were separated distinctly from CO2/N2mixture with the retention times of N2and CO2were3.72min and8.34minrespectively. The similar result was gained from the CH4/CO2separation experimentwith retention times of4.77min and8.36min respectively.At last, we choose different organic amines as nucleophile to react with thetriazine introducer cyanuric chloride. Unfortunately, product of substitution reaction(PAF-53and PAF-54) has shown a negligible BET surface area (SBET of PAF-53isnearly none, SBET of PAF-54is93.2m2g-1). However, the selectivity of CO2/N2canreach as high as83calculated by Henry’s Law, the selectivity of CO2/CH4also canreach18.1which reveals that PAFs-54has exciting potential in gas separation.