International News
HEAT STORAGE :
SCIENTISTS DEVELOP
MATERIAL THAT IS STABLE , EFFICIENT AND ECO-FRIENDLY
By Martin-Luther-Universität Halle-Wittenberg
new heat storage material could help to significantly
A improve the energy efficiency of buildings .
Developed by researchers at Martin Luther University Halle- Wittenberg ( MLU ) and the University of Leipzig , this material can be used to store surplus heat and release it back into the environment when needed .
Unlike existing materials , this new one can absorb significantly more heat , is more stable , and is made of harmless substances . In the Journal of Energy Storage the team describes the formation mechanism of the material .
The invention is a so-called shape-stabilised phase change material . It can absorb large amounts of heat by changing its physical state from solid to liquid . The stored heat is then rereleased when the material hardens .
" Many people are familiar with this principle from hand warmers ," explains Professor Thomas Hahn from the Institute of Chemistry at MLU . However , the invention from Halle won ' t be used in coat pockets . Instead , it could be used by the construction industry as large panels that could be integrated into walls . These would then absorb heat during the sunny hours of the day and release it again later when the temperature goes down .
This could save a lot of energy : The researchers have calculated that when the new material heats up , it can store -- under the right conditions -- up to 24 times per 10 degrees Celsius more heat than conventional concrete or wallboard .
Unlike hand warmers , the panels made of this material mixture do not melt when they absorb heat . " In our invention , the heat storage material is enclosed in a framework of solid silicate and cannot escape due to high capillary forces ," explains Hahn . Most importantly , the substances used in its production are environmentally friendly : harmless fatty acids like those found in soaps and creams .
Even the additives that lend the material its strength and increased thermal conductivity can be obtained from rice husks .
In the current study , the team describes the steps involved in creating the structure of the material and how the different chemicals influence each other . For this , the team received
All images by Uni Halle / Marian Sorge
support from a group of researchers led by Professor Kirsten Bacia from MLU , who used fluorescence microscopy to visualise the mechanism .
" The knowledge we are gaining can be used to further optimise the material and to potentially produce it on an industrial scale ," says Felix Marske , who drove the development forward as part of his doctorate with Thomas Hahn .
At present , the material is still only being produced in small quantities in the laboratory . In the future , it can be combined with other steps to help to make buildings significantly more energy efficient or to passively cool photovoltaic systems and batteries , thereby increasing their efficiency .
The use of this material can be expanded into other sectors that require cooling , such as solar photovoltaic panels and batteries . RACA
The new material that has been developed .
Felix Marske holds a sample of the new material .
www . refrigerationandaircon . co . za RACA Journal I July 2022 7