Yankai Li

Efficient CO2 capture by a task-specific porous organic polymer bifunctionalized with carbazole and triazine groups

A porous triazine and carbazole bifunctionalized task-specific polymer has been synthesized via a facile Friedel-Crafts reaction. The resultant porous framework exhibits excellent CO2 uptake (18.0 wt%, 273 K and 1 bar) and good adsorption selectivity for CO2 over N2.

In situ interfacial growth of zeolitic imidazolate framework (ZIF-8) nanoparticles induced by a graphene oxide Pickering emulsion

A novel method of an in situ interfacial growth of nanoparticles induced by a Pickering emulsion was proposed for the fabrication of hollow composites. With the interfacial growth of ZIF-8 nanoparticles at the n-octanol/water interface of a Pickering emulsion stabilized by graphene oxide (GO), the hollow ZIF-8/GO composite was obtained.

Dynamic hydrophobic hindrance effect of zeolite@zeolitic imidazolate framework composites for CO2 capture in the presence of water

For the real industrial process of CO2 capture, it is still a great challenge for adsorbents to exhibit excellent CO2 adsorption capacity in the presence of water. By combining a pre-seeding process and a two-step temperature controlling crystallization, a zeolitic imidazolate framework (ZIF-8) shell is introduced on the commercial zeolite adsorbent (5A) core to produce a series of 5A@ZIF-8 composites with an enhanced surface hydrophobicity. Each 5A@ZIF-8 composite exhibits a dynamic hydrophobic hindrance effect for the separation of CO2 from the simulated humid flue gas (15% CO2 and 90% humidity at 298 K). Among these, the CO2 adsorption capacity and the CO2/H2O selectivity of 5A@ZIF-8(I) can be as high as 2.67 mmol g−1 and 6.61, respectively, at the optimized adsorption time of 10 min. More importantly, over 10 adsorption–desorption cycles, there is almost no degradation of the adsorption performance. Therefore, the novel strategy of utilizing the dynamic hydrophobic hindrance effect through a core–shell structure would be a good solution for improving the CO2 separation performance in practical applications.

Porosity-induced emission: exploring color-controllable fluorescence of porous organic polymers and their chemical sensing applications

Most organic dyes dissipate their excitation energy in the aggregated state because of the “aggregation-caused quenching” effect, deteriorating their application in optoelectronic devices. To prevent the “aggregation-caused quenching” effect, we incorporate a dye-based fluorophore into a porous organic polymer skeleton because porosity would allow the spatial isolation of fluorophores to maintain their emission. Tuning the fraction of fluorophores in the skeleton of FL-SNW-DPPs could spread the emission color coverage from red to blue in both solid-state and suspension. More importantly, the combination of fluorescence and porosity of FL-SNW-DPPs would provide more space to transduce the molecular interaction between adsorbed analytes and fluorophores to the detectable changes in light emission, leading to the fluorescence-off or fluorescence-on detection of electron-deficient or electron-rich analytes.

A diketopyrrolopyrrole-based fluorescent porous organic polymer as fluoride sensing monolithic device

Diketopyrrolopyrrole-based moiety was polymerized with tetrakis(4-ethynylphenyl)methane to afford a porous organic polymer with good porosity and accessible active sites. This polymer inherited the fluorescent nature of parent monomer and underwent colorimetric and fluorescence change upon the exposure to fluoride anions. Remarkably, a superior selectivity towards fluoride anions was observed with the limit of detection of 18 ppb. Moreover, the polymer could be recycled several times. Finally, the porous organic polymer was successfully immobilized on a macroporous sponge to obtain a fluorescence sensing device, which was efficient in detection and was easier to handle when compared with the device obtained using polymer powder.

Induced-fit adsorption of diol-based porous organic polymers for tetracycline removal

Adsorption is recognized as one of the most efficient approaches for antibiotics removal from water. Inspired by the enzyme-substrate interaction model, we proposed induced-fit adsorption (IFA) model, and rationally designed and fabricated diol-based porous organic polymers (POPs) as adsorbents for tetracycline (TC) removal. For 2,3-naphthalenediol-based POP (NTdiol-POP), the preferable geometry of diol-groups contributed to the high binding energy with TC species and flexible methylene linkages between neighboring rigid naphthalene rings gave rise to precisely matching between TC species and adsorbents, that is, the induced-fit conformation change. As a result, NTdiol-POP exhibited a high saturated adsorption capacity of 155.8 mg g-1. More importantly, NTdiol-POP exhibited excellent TC removal efficiencies in both concentrated solution (96% for 4 p.p.m) and trace level solution (97% for 250 p.p.b).