Breathing porous liquids – From fundamental understanding towards innovation

• Applicant: Professor Dr. Sebastian Henke
• Subject Area: Solid State and Surface Chemistry, Material Synthesis ; Physical Chemistry of Solids and Surfaces, Material Characterisation
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 570979718

This research project explores a new class of advanced materials called breathing porous liquids (bPLs), which combine the fluidity of a liquid with the gas-adsorbing capabilities of porous solids. Unlike conventional liquids, which absorb gases in direct proportion to pressure, bPLs exhibit a sigmoidal gas solubility profile. This means they show a sharp increase in gas uptake over a narrow pressure range – much like the oxygen binding curve of blood. This unique property is made possible by dispersing porous and responsive metal-organic framework (MOF) submicro-particles in non-penetrating carrier liquids. The MOF particles expand and contract in response to gas pressure, allowing the liquid suspension to adsorb much more gas than would otherwise be possible within a small pressure window. This behaviour promises high working capacities and energy-efficient gas separation, making bPLs highly attractive for applications such as carbon capture, gas separation and purification. The project builds on our recent discovery that the breathing behaviour of MOFs is preserved even when the responsive solid particles are dispersed in a liquid medium. Having demonstrated this proof of concept, we now aim to fully develop the potential of bPLs and move the technology closer to real-world applications. The project will focus on improving material formulation by increasing the amount of porous solid that can be stably suspended in the liquid, enhancing both gas uptake and flow behaviour. We will also explore new combinations of solids and carrier liquids to create bPLs with lower energy losses, faster response times, and improved long-term stability. A key aspect of the research is understanding how quickly and efficiently bPLs adsorb and release gases. To this end, we will use laboratory-based sorption measurements and high-resolution synchrotron techniques to observe, in real time, how these materials respond to changes in gas pressure. We will also investigate whether ultrasound can serve as a non-thermal, energy-efficient method to accelerate gas release and improve the regeneration of bPLs. Over the course of the project, we expect to develop several high-performance bPL formulations tailored for specific targets such as carbon dioxide removal and hydrocarbon separation. We will also have gained fundamental insights into how the structural properties of the solid components control the gas sorption behaviour of the liquid system. This research marks an important step toward the creation of adaptive, energy-efficient materials for a more sustainable future in gas separation and storage.

• DFG Programme: Research Grants