| As the development of our society,advanced materials with high-stable and low-density are desirable.Based on the "Framework Chemical" concept and the principle of static-determined structure engineering applied in the macroscopic structures,it is realistic to form the networks with excellent stability and low density at molecular level through covalent forces exist between the rigid "knot" and "rod".Adamantane is a chemical molecule with highly systematic cage-like structure and the hydrogen linked with bridgehead carbon is active.Thus,this molecule and the corresponding derivatives based on it have great potential to construct advanced organic materials.In order to construct the advanced polymers with excellent chemical and hydrothermal stability,in this study,series of microporous organic frameworks based on adamantane were designed and synthesized,according to Framework Chemical.And the properties of pore and adsorption of small gases were further explored.The detailed work were listed as follows:1.Three microporous organic polymers(MOP-Ad)have been synthesized via Suzuki coupling polymerization of 1,3,5,7-tetrakis(4-bromophenyl)adamantane "knots" with three phenylboronic acid-type "rods".Gas adsorption studies of the MOP-Ad materials demonstrated their permanent porosity and good gas storage capabilities(120.3 cm3 g-1 for H2 at 77 K and 1.0 bar,52.4 cm3 g-1 for CO2 at 273 K and 10 bar,as well as moderate CO2/N4 and CO2/CH4 adsorption selectivity.Moreover,high thermal stability(up to 520 ?)and remarkable chemical resistance to strong acids and bases were found in these polymers,making them suitable candidates as gas storage materials in harsh chemical environments.2.In view of the problem of the instability of most microporous organic frameworks in various solvents,such as DI water,acids and bases,we designed and synthesized a three-dimensional microporous organic frameworks based on adamantane(MOP-Ad-1)via Suzuki coupling reactions,which exhibited ultra-high physicochemical and hydrothermal stabilities.Additionally,the post-synthesized modification of these materials thought direct nitration of aryl linkers followed by reduction(MOP-Ad-1-NH2)were also showed promising CO2/N2 breakthrough separation performance for carbon capture and storage,which the CO2 uptake capacities were up to 104.4 cm3 g-1 at 273 K and 10 bar,and the selectivity of CO2/N2 values was up to 75.1 in the same conditions.Additionally,the Qst was calculated at 273 K and 298 K,demonstrated the adsorption between CO2 and MOP-Ad-1-NH2 physical absorption.3.Two microporous organic frameworks based on adamantane(hereafter denoted as MF-Ad-4 and MF-Ad-5)were fabricated through Sonogashira-Hagihara coupling polycondensation of aryl halides and alkynes.Results show that both types of MF-Ad had similar porous properties but exhibited excellent CO2 uptake capacities were up to 72.5 cm3 g'I at 273 K and 10 bar,CO2/N2 selectivity was up to 84.5 in the same conditions.This superior performance could be attributed to the narrower pore-size distribution of these MF-Ad frameworks herein,as well as the ?-conjugated skeleton.Taking advantage of the superhydrophobic wettability of the resulting MF-Ad networks,wire mesh scaffolds were used to fabricate superhydrophobic films with polydimethylsiloxane(PDMS)acting as a binder.These films displayed excellent instant hydrocarbon/water separation efficiency(up to 99.6%),which was maintained at a constant level after five repeated cycles.This work provides a novel insight into the fabrication of microporous organic frameworks and extends their applicability to carbon capture and storage and absorption of hazardous organic pollutants. |
PDF Full Text Request