Wenyan Shi,Xiaolong Han,Fang Bai,Chao Hua,Xingzhong Cao
The metal–organic framework MOF-505 particles were synthesized and incorporated into the polyethylene glycol (PEG) matrix to prepare mixed matrix membranes. A series of methods were used to characterize the structure and morphology of MOF-505 particles and membranes. The prepared MOF-505 had a well-developed pore structure, a large number of metal sites for selective adsorption of thiophene and good compatibility with polymer matrix. Accordingly, the desulfurization performance of the membrane was improved effectively. The effects of the content of MOF-505, operating temperature and feed sulfur content on membrane performance were investigated by pervaporation experiments. The membrane with 3 wt% MOF-505 showed the optimal desulfurization performance with a permeation flux of 2.66 kg/(m 2 ·h) and an enrichment sulfur factor of 8.15, which were increased by 158% and 25% versus pristine membrane, respectively.
Given the fact that solvothermal synthesis is the most common synthetic method to obtain metal–organic frameworks (MOFs) on a gram scale, it still remains a great challenge to produce MOFs in a scalable and sustainable synthetic process. In this work, we develop a facile and rapid synthesis of copper-based MOF-505 by the exploitation of layered (Zn,Cu) hydroxy double salt as the intermediate for efficient MOF-505 crystallization at room temperature, in which [(Zn,Cu)(OH)NO3] is synthesized by reacting ZnO with Cu(NO3)2. Under an optimized reaction time of 25 min, MOF-505-25 exhibits a Brunauer–Emmett–Teller (BET) surface area of 1076 m2 g−1 and the pore size is narrowly distributed at 5.9 and 8.0 Å. With respect to CO2 adsorption and separation performance, MOF-505-25 shows a moderate CO2 uptake of 3.51 mmol g−1 at 298 K and 100 kPa and high CO2/CH4 and CO2/N2 adsorption selectivities of 7 and 29. Particularly, the formation of MOF-505 can be completed within a short reaction time (less than 30 min) whilst maintaining high quality. This facile and rapid room temperature synthetic procedure would pave the way for promoting the development of MOF materials large-scale production with minimizing the energy input.
Yongwei Chen,Houxiao Wu,Zewei Liu,Xuejiao Sun,Qibin Xia,Zhong Li
Mechanochemical synthesis, driven the chemical transformation by mechanical force, has been a rapid and efficient strategy to prepare metal–organic frameworks (MOFs). In this work, a liquid-assisted mechanochemical method has been successfully applied to the synthesis of copper based MOF-505. The crystallinity and porosity of MOF-505 were investigated by adjusting the synthesis parameters, such as added solvent (type and amount) and grinding time. Results showed that the type and amount of added solvent were crucial parameters for the mechanochemical synthesis of MOF-505. Furthermore, the optimizations of MOF-505 synthesis were carried out: grinding Cu(OAc)2·H2O and H4bptc as starting materials for 80 min with 0.4 mL of DMF assisted, giving MOF-505-K with Brunauer–Emmett–Teller (BET) surface area of 977 m2/g. Meanwhile, MOF-505-K had moderate CO2 adsorption capacity of 2.01 mmol/g at 298 K and 100 kPa. The adsorptive selectivity determined from ideal adsorbed solution theory (IAST) indicated that MOF-505-K had high CO2/N2 and CO2/CH4 selectivities (26.6 and 5.5) at 298 K. Highly efficient mechanochemical synthesis of MOF-505 provides the promise to facilitate the industrial application of CO2 capture.
Wang Guang,Fan Hongzhao,Li Jiawang,Li Zhigang,Zhou Yanguang
Improving interfacial thermal transport is crucial for heat dissipation in devices with interfaces, such as electronics, buildings, and solar panels. Here, we design a strategy by utilizing the water adsorption-desorption process in porous metal-organic frameworks (MOFs) to tune the interfacial heat transfer, which could benefit their potential in cooling or heat dissipation applications. We observe a changeable thermal conductance across the solid/porous MOF interfaces owing to the dense water channel formed by the adsorbed water molecules in MOFs. Our experimental and/or modeling results show that the interfacial thermal conductance of Au/Cu 3 (BTC) 2 , Au/Zr 6 O 4 (OH) 4 (BDC) 6 and Au/MOF-505 heterointerfaces is increased up to 7.1, 1.7 and 3.1 folds by this strategy, respectively, where Cu 3 (BTC) 2 is referred to as HKUST-1 and Zr 6 O 4 (OH) 4 (BDC) 6 is referred to as UiO-66. Our molecular dynamics simulations further show that the surface tension of Au layer will cause the adsorbed water molecules in MOFs to gather at the interfacial region. The dense water channel formed at the interfacial region can activate the high-frequency lattice vibrations and act as an additional thermal pathway, and then enhance heat transfer across the interfaces significantly. Our findings revealed the underlying mechanisms for tailoring thermal transport at the solid/porous MOF heterointerfaces by water adsorbates, which could motivate and benefit the new cooling system design based on MOFs.
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