Percolation-assisted coating of metal-organic frameworks on porous substrates
Percolation-assisted coating of metal-organic frameworks on porous substrates
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DOI：
10.1016/j.memsci.2022.121202
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发表时间：
2022-11
影响因子：
9.5
通讯作者：
Rajan R Bhawnani;Rohan Sartape;Aditya Prajapati;Prem K. R. Podupu;Paria Coliaie;Arnav N. Nere;Meenesh R. Singh
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文献类型：
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作者：
Rajan R Bhawnani;Rohan Sartape;Aditya Prajapati;Prem K. R. Podupu;Paria Coliaie;Arnav N. Nere;Meenesh R. Singh
在过去的二十年中，在多孔固体基底上制备金属有机框架（MOFs）用于气体分离和催化应用的薄膜已经取得了显著的进展。为了增强膜的物理和化学稳定性，已经实施了各种自上而下和自下而上的方法。虽然这两种方法都有一些优点，但由于缺乏与基材的粘附力、膜的破裂和不均匀的覆盖率，它们大多受到限制。因此，需要改进用于制造坚固、均匀和可扩展的膜的涂布方法。在这里，我们开发了一种新的蒸馏辅助涂层（PAC）的过程中，结合自上而下和自下而上的方法在连续流动的微流体装置存款HKUST-1的多孔基板上，产生受控的膜厚度和质量负载。PAC过程是使用多物理建模方法优化设计的微流控反应器，它可以很容易地按比例放大和部署，以制造各种多孔基板上的MOF膜。通过控制反应混合物的停留时间和温度，可以实现在10-200 μm范围内的MOF膜的期望厚度。合成的膜的特征在于使用超声处理的物理粘附，使用扫描电子显微镜的膜覆盖率，和使用孔隙率计的孔隙率。合成的膜的性能是基准的有效分离50体积%的CH 4-H2气体混合物的分离因子为4。该微流控装置还适用于合成各种M0 F的膜，如M0 F-5、M0 F-505（也在这里报道）、UIO-66等，在宽范围的多孔基底上。最后，我们提出了一个多室设计的微流控装置的高通量筛选薄膜生长使用PAC过程。
In the past two decades, significant advancements have been made toward thin film fabrication of metal-organic frameworks (MOFs) on porous solid substrates for gas separation and catalysis applications. To enhance the physical and chemical stability of the films, various top-down and bottom-up approaches have been implemented. While both approaches have some advantages, they are mostly limited due to a lack of adhesion with the substrate, cracking of the films, and non-uniform coverages. Therefore, there is a need for improvement in the coating processes for the fabrication of robust, uniform, and scalable films. Here, we develop a novel percolation-assisted coating (PAC) process that combines top-down and bottom-up approaches in a continuous-flow microfluidic device to deposit HKUST-1 on a porous substrate, yielding controlled film thicknesses and mass loading. The PAC process is optimized using a Multiphysics modeling approach to design the microfluidic reactor, which can be readily scaled up and deployed to fabricate MOF films on various porous substrates. The desired thickness in the range of 10–200 μm of the MOF film can be achieved by controlling the residence time and temperature of the reaction mixture. The synthesized film is characterized for physical adhesion using sonication, film coverage using scanning electron microscopy, and porosity using a porosimeter. The performance of synthesized films is benchmarked for the effective separation of 50 vol% CH4–H2gas mixture with the separation factor of 4. The microfluidic device is also applicable to synthesize films of various MOFs like MOF-5, MOF-505 (also reported here), UIO-66, etc., over a wide range of porous substrates. Lastly, we propose a multi-chamber design of the microfluidic device for high-throughput screening of thin-film growth using the PAC process.