Thinner metal-organic framework membranes, larger-scale applications
Thinner metal-organic framework membranes, larger-scale applications lead image
Organic ligands link metal ions to build metal-organic frameworks (MOFs), which offer uniform nanosized pores, high stability, and easy crystallization. These properties make MOFs promising for customizable, membrane-based separation of gas molecules for different environmental and industrial purposes.
As such, interest in MOF membranes has grown in the past decade and various strategies to fabricate them have emerged. Liu et al. summarize the advantages and disadvantages of existing techniques used to create ultrathin MOF membranes. They compare how films produced by these differing methods perform in potential applications, including gas separation, ion transport, ion-ion separation, and desalination.
“Reading this review will help students and scientists working in the field understand the latest state-of-the-art techniques to synthesize ultrathin MOF membranes,” said author Kumar Varoon Agrawal.
The authors also present current challenges and future opportunities in the MOF membrane field. Scalable protocols to fabricate high-performance MOF membranes do not yet exist.
“A very important aspect here is the potential large-scale application of MOF-based membranes, which in many cases is limited by high cost and scalability challenges in these membranes,” Agrawal said.
Developing techniques capable of producing thinner MOF films could help combat this cost. Thinner MOF films perform better because they are more permeable, which means less membrane is required.
Current MOF films are three-dimensional and usually between 100 and 1000 nanometers thick. The authors hope that fine-tuning crystallization conditions of MOF membranes will eventually result in two-dimensional films with enhanced performance and fabrication scalability.
Source: “Towards ultrathin metal-organic frameworks membranes for high-performance separation,” by Qi Liu, Heng-Yu Chi, Shuqing Song, Ranadip Goswami, and Kumar Varoon Agrawal, APL Materials (2023). The article can be accessed at https://doi.org/10.1063/5.0169507 .
