Simultaneous purification and functionalization of MOFs using natural phospholipids

An efficient and sustainable method for the purification of metal–organic frameworks (MOFs), particularly at the nanoscale, which employs phospholipids to induce phase separation and provide a biocompatible coating in a single step.

Market need: The purification of nanoscale metal–organic frameworks (MOFs) (<200 nm) represents an industrial bottleneck. Conventional methods, such as centrifugation or solvent washing, lead to particle aggregation, substantial material loss, and are ineffective at removing non-volatile impurities. In addition, processes such as solvent exchange or thermal activation are time-consuming and can compromise the structural integrity of thermally sensitive frameworks. There is an urgent need for scalable and sustainable strategies that preserve the intrinsic properties of the material.

Proposed solution: A method has been developed that exploits the selective interaction between MOFs and natural phospholipids directly within the synthesis mixture. Upon the addition of a second immiscible liquid phase, phase separation is induced, causing the purified MOF–phospholipid complex to migrate into the new phase, thereby removing impurities in a straightforward manner.
The process has been successfully validated for different MOFs, including PCN-222, MOF-801, and PCN-224, demonstrating that it not only purifies the material but also functionalizes it with a biocompatible coating that facilitates its subsequent application in drug delivery systems or catalysis.

Competitive advantages

Process integration: combines purification and functionalization into a single, mild step.
Sustainability: employs natural phospholipids and drastically reduces the use of toxic solvents (e.g., improving the E-factor).
Structural preservation: prevents aggregation and preserves the porosity of fragile MOFs by avoiding extreme temperatures or centrifugation conditions.
Scalability: rapid and straightforward phase separation.