Periodic Reporting for period 4 - WATUSO (Water Forced in Hydrophobic Nano-Confinement: Tunable Solvent System)
Berichtszeitraum: 2024-03-01 bis 2025-06-30
Water and nanoporous materials are omnipresent in society. Nanoporous adsorbents, catalysts, ion exchange materials and membranes are workhorses of chemical and related industries. The phaseout of organic solvents driven by health and environmental concerns pushes industries to greener alternatives, and water is an obvious choice. Electrification of the chemical industry to avoid the use of fossil carbon energy sources makes electrolysis processes with aqueous electrolytes a crucial technology for producing green chemicals. Tuning water properties provides answers to many needs. It is key to preservation of foodstuff and in pharmaceutical and cosmetics formulation. In the hydrogen economy, water is the feedstock for producing green hydrogen. A majority of nanoporous materials are hygroscopic and spontaneously saturated with water by capture of water vapor. Atmospheric water vapor capture is a means to produce fresh water. Climate change, pollution, and overuse are making water critically scarce, driving its economic value. Being a necessity for life, food and industry, water scarcity is human-driven. This project contributes to finding solutions for clever water usages and water savings in critical areas such as fresh water production, sustainable energy and environmental protection.
The overall objectives are to explore nanoconfined water properties under a wide range of temperature and pressure conditions. Nuclear Magnetic Resonance and X-Ray Diffraction investigations are performed in situ at pressures up to 300 bar and temperatures from -40°C up to 150°C. The proton is a handy atomic nucleus for investigating confined water, and rapid and detailed NMR investigations can be performed using NMR-sensitivity enhancement by hyperpolarization. Unprecedented detail on formation and evolution of confined water structures, gas clathrate hydrates and ice structures are obtained. The aim is to perform dielectric spectroscopy for quantifying polarity simultaneously with NMR spectroscopy in one instrument. Fundamental understanding of structure-function relations between nanoporous host and confined water is seen as key to solving standing grand technological challenges for sustainable energy and environmental protection. Combining atmospheric water vapor capture with electrolysis is an ambitious aim to provide hydrogen gas as a handy clean energy solution for everyone anywhere on the planet. WATUSO water-tuneable-solvent systems offer solutions for avoiding atmospheric ammonia emission from livestock housing, a major and persistent agricultural problem.
Several scientific breakthroughs were achieved. Water-alcohol mixtures confined in zeolite nanopores were found to interact in a peculiar way with the pore walls. Alcohol molecules were observed to make hydrogen bonds to Si-O-Si siloxane oxygen atoms of the zeolite framework. This newly discovered universal mechanism of adsorption of molecules capable of H-bonding co-exists with the traditionally accepted physisorption mechanisms. Enhanced nucleation and growth of clathrate hydrates from water confined in hydrophobic nanopores were another major achievement. Intrusion of water into hydrophobic nanopores with suitable pore wall functionality enables clathrate formation of H2, CH4 and C2H6 at reduced pressure and temperature. Hydrated carbomers are used in a score of applications (cosmetics, paints,..) for thickening, suspending, dispersing and stabilizing products. Improved insight in the process of water incorporation, polymer unfolding and hydration was obtained. This offered a molecular level view on the rheology of hydrogels, allowing to improve mixing technology for carbomer containing emulsions and dispersions.
Energy Storage: We identified a "memory effect" in porous ice that allows for the efficient storage of gases like methane and hydrogen. Gas release and uptake occur swiftly simply by altering pressure at a constant low temperature.
Green Energy Generation: Inspired by hygroscopic porous materials, we designed autonomous panels that produce green hydrogen directly from atmospheric water vapor using only solar energy. This allows for locally produced, low-pressure hydrogen to power clean cookstoves in the Global South, offering a sustainable alternative to wood and charcoal.
Infrastructure & Industry: We synthesized layered double hydroxide nanotubes to create luminescent sensors that detect concrete carbonation. We provided molecular-level explanations for how polymers hydrate in gels when using novel magneto-hydrodynamic mixers.
Agriculture: We addressed air pollution from livestock farming by optimizing air scrubbers. By extracting water vapor from vented air alongside ammonia gas, we achieved a tenfold reduction in water consumption compared to state-of-the-art scrubbers.
- Fresh water production from water vapor contained in atmospheric air is a possible solution to fulfil human water needs in case of local water scarcity owing to climate change. The WATUSO approach involves water vapor adsorption in porous thermo-responsive hydrophilicity switching polymers which turn hydrophobic and leak water upon solar heating. Energy consumption estimates of existing and emerging water-from-air technologies including the WATUSO system enabled to identify of optimal water-from-air technology depending on the climate, relative humidity, and temperature profiles.