Zijun Bian

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.

Interfacial Growth of Metal Organic Framework/Graphite Oxide Composites through Pickering Emulsion and Their CO2 Capture Performance in the Presence of Humidity

We proposed an in situ interfacial growth method induced by the Pickering emulsion strategy to produce metal organic framework (MOF)/graphite oxide (GO) composites of Cu3(BTC)2/GO, in which GO was demonstrated to be a promising stabilizer for producing the Pickering emulsion and provided a large interfacial area for the in situ growth of Cu3(BTC)2 nanoparticles. When Cu3(BTC)2/GO composites were used as adsorbents for CO2 capture from the simulated humid flue gas, they showed both significantly improved thermodynamic and dynamic properties. Because most of the H2O molecules were adsorbed on the highly exfoliated GO sheets in Cu3(BTC)2/GO-m, CO2 uptake reached 3.30 mmol/g after exposure to the simulated flue gas for 60 min and remained unchanged for up to 120 min. This highlighted its potential application for real CO2 capture. More importantly, the in situ interfacial growth of nanoparticles induced by Pickering emulsions would be a promising strategy for designing and fabricating nanocomposites.

The effect of a P123 template in mesopores of mesocellular foam on the controlled-release of venlafaxine.

A series of mesocellular foams (MCFs)-based mesoporous silica nanospheres (DH-MCF-P123-n, (n=12, 2, 0.5)) were synthesized as controlled-release deliveries for a typical antidepressant drug, venlafaxine. The foams were 3-(2,3-dihydroxypropoxyl)propyl-grafted and the P123 template partially preserved. We studied the release profiles of venlafaxine-loaded DH-MCF-P123-n in simulated gastric fluid (SGF) and simulated intestinal fluid (SIF), respectively, as well as their corresponding venlafaxine loading capacities. Appropriate amounts of P123 template preserved in mesopores showed an efficient synergetic effect on increasing venlafaxine loading capacity and controlled-release property. Up to 90.87% (mass fraction) of venlafaxine could be loaded into DH-MCF-P123-2. For this carrier, 36% of venlafaxine was released after 1h of incubation in SGF and 53% of venlafaxine was released after 12h in SIF. The mechanisms of the loading and releasing processes were tentatively described based on the release behaviors.

Dynamic properties in CO2 adsorption on amine-modified MCM-41

Adsorption is an effective method for separating CO2 from flue gases. The fixed-bed adsorption and desorption of CO2 on MCM-41 and amine-modified MCM-41 (APTS-MCM-41) were studied. The dual-site Langmuir model, which considered both chemical adsorption and physical adsorption, was used to fit the experimental data. The resulting thermodynamic parameters, such as the saturated adsorption capacity, equilibrium constant, enthalpy and entropy, suggested the feasibility of the CO2 adsorption on APTS-MCM-41, as well as the reality of the adsorption mechanism. A dynamic model based on the linear driving force approximation for the mass transfer was used to describe the adsorption kinetics of CO2. The influences of the operating conditions on the breakthrough curve were investigated using both experimental and theoretical methods. Meanwhile, the impacts of changing values of the axial dispersion coefficient and the mass transfer coefficient were investigated. It showed that the amine-modified mesoporous materials would be a promising sorbent in the future CO2 capture.

Asymmetric Polyimide Mixed Matrix Membranes with Porous Materials-Modified Surfaces for CO 2 /N 2 and CO 2 /CH 4 Separations

兼具高通量和高选择性的气体分离膜是研究膜分离材料的目标.采用相转化法制备了聚酰亚胺非对称膜,并将其作为基底膜材料,分别在其表面修饰掺有金属有机框架材料Cu3（BTC）2（1,3,5-均苯三甲酸合铜）,沸石咪唑酯骨架材料ZIF-8以及镁铝水滑石Mg Al-LDHs的聚酰胺酸溶液,经热亚胺化后制成非对称混合基质膜.研究了该系列非对称混合基质膜的结构特性和对CO2、CH4和N2气体分离性能;考察了ZIF-8的掺杂量对非对称混合基质膜透气性能的影响.结果表明非对称聚酰亚胺膜的表面修饰可有效地改变膜的表面性质,掺杂ZIF-8的非对称混合基质膜气体的透气性能和选择性都增加,且掺杂量为5%（w）时CO2/N2和CO2/CH4的理想选择性分别高达24和83,为合成高效的CO2分离膜提供了借鉴.