Thermal systems use heat to produce cold, and vice versa. To do so, a material is needed that can dissipate water vapor particularly well and quickly. A new method simply applies this property as a layer onto the components.
Refrigerators have the human body as an example: When we perspire, water evaporates on our skin and cools it. The lower the atmospheric pressure, the easier this is. If the process is transferred to a vacuum, water already evaporates at a few millibar and a temperature of 10 degrees. So that the devices continuously cool, the vapor must be removed. This is achieved, for example, by an electric compressor, just as the water vapor in our refrigerators is removed from the gas phase and then re-liquefied. An alternative is the thermal compressor, a porous material that can absorb water vapor. In this variant, the operating power is not electrical, but thermal. Heat pumps or chillers operated in this manner produce cold from heat, and vice versa. So far, however, these have not been able to prevail entirely over their electricity-powered counterparts; their power density is too low. What is lacking are materials and components that are capable of sufficiently discharging the water vapor in a shorter time.
Materials must absorb water vapor
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg have now closed this gap. Their metal organic frameworks (MOFs) are particularly well suited to absorb water vapor. In this process, a metallic cluster and organic linkers together form a three-dimensional porous structure. “MOFs can be put together arbitrarily like Lego bricks and outperform every previously known class of material in terms of flexibility. The materials are porous and have interior surfaces which can add up to 4,000 square meters per gram. This is sufficient space for the water vapor to be able to adsorb and accumulate,” explains Dr. Stefan Henninger, Head of the Sorption Materials Group at the ISE.
The Latest on: Metal organic frameworks
via Google News
The Latest on: Metal organic frameworks
- Observation of reduced thermal conductivity in a metal-organic framework due to the presence of adsorbateson August 11, 2020 at 2:09 am
Metal-organic frameworks are attractive adsorbents for gas storage and separations, but appropriate heat dissipation is important for practical application. Here the authors use experiment and theory ...
- Sunlight can turn seawater into clean drinking water in minuteson August 10, 2020 at 9:00 am
Australia-based researchers used a metal-organic framework (MOF), a type of lattice-like crystal, to desalinate water with sunlight.
- Sun, smarts and clean drinking wateron August 10, 2020 at 8:35 am
Now, in a new paper in the journal Nature Sustainability, a second team reports that it has been able to transform brackish water and seawater into clean drinking water in less than 30 minutes using a ...
- Breakthrough technology purifies water using the power of sunlighton August 10, 2020 at 8:05 am
A research team, led by Australia's Monash University, has been able to transform brackish water and seawater into safe, clean drinking water in less than 30 minutes using metal-organic frameworks ...
- Metal organic frameworks made to act as liquidson August 10, 2020 at 8:03 am
Innovative materials called metal organic frameworks (MOFs) could become much more versatile following research that shows that they can be manipulated as liquids.
- Scientists turn seawater into drinkable freshwater using metal compounds, sunlighton August 10, 2020 at 8:02 am
Researchers have successfully turned brackish water and seawater into clean, potable freshwater using metal-organic frameworks, MOFs, and sunlight.
- Using porous crystals to harvest lighton August 10, 2020 at 5:45 am
Drawing inspiration from photosynthesis, KAUST researchers have developed a new spin on metal organic frameworks (MOFs) that could help solar cells to gather more energy from the Sun.
- A nature-inspired hydrogen-bonded supramolecular complex for selective copper ion removal from wateron August 7, 2020 at 2:36 am
Heavy metals and metalloids pose major threats to health and environmental ecosystems, thus systems for low-cost remediation are needed. Here the authors report the scalable design of a ...
- Green Science Alliance Developed MOF (Metal Organic Framework) with Photocatalytic Activityon August 4, 2020 at 6:12 am
Metal organic frameworks (MOFs), also known as porous coordination polymers (PCPs), are materials composed of metal cations and organic ligands that bridge component metals. MOFs are synthesized ...
- Green Science Alliance Developed MOF (Metal Organic Framework) with Photocatalytic Activityon August 4, 2020 at 5:38 am
Photocatalytic reaction can directly convert solar energy to chemical energy so that it can produce hydrogen and oxygen, by decomposing ...
via Bing News