The need for speed in separations and sensing Transport diffusion in metal-organic frameworks

Promovendus/a: Margot Fabienne Kristoffel Verstreken

Promotor(en): Prof. dr. ir. Rob Ameloot

Nanoporous materials, with their sponge-like structures, offer exciting opportunities to make industrial processes more efficient and environmentally friendly. Among these, metal-organic frameworks (MOFs) stand out as a groundbreaking class of materials. MOFs have unique features, such as large internal surfaces, adjustable pore sizes, and structural flexibility, making them ideal for applications like gas storage, separations, catalysis, and even chemical sensors. While much research focuses on how well these materials can adsorb molecules, this Ph.D. work highlights a property that is often overlooked: how quickly molecules move through them. This property, called mass transfer, plays a crucial role in real-world applications. The role of mass transfer and its relation to efficient separation processes is explored in this work.

Volatile organic compounds (VOCs) are gases widely present in our surroundings and are important indicators for air quality, disease diagnosis, food safety, or chemical leaks. Yet, detecting VOCs in these complex applications is challenging due to their low concentrations and many interfering compounds. Traditional sensors struggle to correctly identify these components. This work introduces a novel sensing approach: kinetic selectivity sensing. This concept is based on the speed at which gases travel through nanoporous materials. Hence, the mass transfer rates of VOCs are used as the main discriminator to identify specific VOCs of interest. This work demonstrates that kinetic selectivity can direct a new generation of efficient "electronic noses" to detect VOCs with the necessary selectivity lacking in today’s solutions.