(Press-News.org) The search for sustainable new materials to store heat captured from the sun for release during the night has led scientists to a high-tech combination of paraffin wax and sand. Their report on the heat-storing capability of this microencapsulated sand appears in ACS Sustainable Chemistry & Engineering.
Benxia Li and colleagues explain the need for better materials that can store and release heat. These so-called "phase-change" materials" (PCMs) are essential, for instance, for storing heat from the sun for use in providing energy at night or during cloudy periods. PCMs absorb, store and release heat when changing "phases" from a solid to a liquid and vice versa. They have applications that range from expanding use of solar energy to heat-regulating greenhouses to clothing that keeps soldiers or campers warm on cold nights outdoors. Existing PCMs have disadvantages, such as the tendency to leak or catch fire, and Li's team set out to find a better material.
They describe a new approach to using paraffin as a PCM. Made from petroleum, paraffin is a waxy material that absorbs heat, melts into a liquid and releases heat as it solidifies. It involves encapsulating paraffin into tiny spheres of silicon dioxide, the stuff of beach sand. The microencapsulated paraffin has several advantages, including a large surface area that can transfer heat, less reactivity with the environment and less likelihood of leaking as it changes phases. Li's team reports successful tests of the material for 30 melting-solidifying cycles with no leaks at a temperature of 158 degrees Fahrenheit. "The high heat storage capability and good thermal stability of the composite enable it to be a potential material to store thermal energy in practical applications," the report concluded.
###
The authors acknowledge funding from the National Natural Science Foundation of China, the National Basic Research Program of China, and the Young and Middle-aged Backbone Teachers Fund of Anhui University of Science and Technology.
The American Chemical Society is a nonprofit organization chartered by the U.S. Congress. With more than 163,000 members, ACS is the world's largest scientific society and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.
To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.
Follow us: Twitter Facebook END
Paraffin encapsulated in beach sand material as a new way to store heat from the sun
2013-03-13
ELSE PRESS RELEASES FROM THIS DATE:
Doing business with a parrot
2013-03-13
This press release is available in German.
VIDEO:
Muffin and 13 other cockatoos showed the skills to wait and trade 'normal' for 'better' or 'more' nuts.
Click here for more information.
Waiting: a clever move!
In the 70ties, self-control of human infants was investigated using the prominent 'Stanford Marshmallow Experiment': the children were presented with a marshmallow and ...
Younger doctors more likely to train and work closer to home
2013-03-13
Younger doctors are more likely than older generations to train and work in the same region as their home before entering medical school. New research published in the Journal of the Royal Society of Medicine investigating the geographical mobility of UK-trained doctors, reveals that 36% attended a medical school in their home region. 34% of hospital consultants and GP partners settled in the same region as their home before entering medical school. The geographical distribution of doctors is an important factor in the equitable distribution of health services.
Trevor ...
Extreme water
2013-03-13
Earth is the only known planet that holds water in massive quantities and in all three phase states. But the earthly, omnipresent compound water has very unusual properties that become particularly evident when subjected to high pressure and high temperatures. In the latest issue of the Proceedings of the National Academy of Sciences (PNAS), a German-Finnish-French team published what happens when water is subjected to pressure and temperature conditions such as those found in the deep Earth.
At pressures above 22 MPa and temperatures above 374°C, beyond the critical ...
Surprising control over photoelectrons from a topological insulator
2013-03-13
Plain-looking but inherently strange crystalline materials called 3D topological insulators (TIs) are all the rage in materials science. Even at room temperature, a single chunk of TI is a good insulator in the bulk, yet behaves like a metal on its surface.
Researchers find TIs exciting partly because the electrons that flow swiftly across their surfaces are "spin polarized": the electron's spin is locked to its momentum, perpendicular to the direction of travel. These interesting electronic states promise many uses – some exotic, like observing never-before-seen fundamental ...
Evidence supports blocking immune response to enhance viral therapy against solid tumors
2013-03-13
Following several years of study, investigators have found more evidence that viral therapy to treat solid tumors can be enhanced by blocking the body's natural immune response.
Oncolytic viruses have shown promise as anticancer agents, with variations of the herpes simplex virus (HSV) among the most commonly used. However, many studies have shown that the effectiveness of viral therapy to eradicate tumors has not been as successful with patients as it has been in the lab. These results have led researchers to examine the body's immune system response to determine what ...
Bradley Hospital researchers find age-related changes in how autism affects the brain
2013-03-13
EAST PROVIDENCE, R.I. – Newly released findings from Bradley Hospital published in the Journal of the American Academy of Child & Adolescent Psychiatry have found that autism spectrum disorders (ASD) affect the brain activity of children and adults differently.
In the study, titled "Developmental Meta-Analysis of the Functional Neural Correlates of Autism Spectrum Disorders," Daniel Dickstein, M.D., FAAP, director of the Pediatric Mood, Imaging and Neurodevelopment Program at Bradley Hospital, found that autism-related changes in brain activity continue into adulthood. ...
Events in the future seem closer than those in the past
2013-03-13
We say that time flies, it marches on, it flows like a river — our descriptions of time are closely linked to our experiences of moving through space. Now, new research suggests that the illusions that influence how we perceive movement through space also influence our perception of time. The findings provide evidence that our experiences of space and time have even more in common than previously thought.
The research, conducted by psychological scientist Eugene Caruso of the University of Chicago Booth School of Business and colleagues, is published in Psychological ...
Study reveals 10 factors in wrongful conviction cases
2013-03-13
Why do innocent people go to jail in the United States every year for violent crimes they did not commit? It's a serious question representing the ultimate miscarriage of justice—taking away the freedom of a factually innocent person while also allowing the guilty person to remain free. The U.S. Department of Justice's National Institute of Justice (NIJ) wanted to learn answers to prevent wrongful convictions in the first place.
Jon B. Gould, J.D., Ph.D., a professor and the director of the Washington Institute for Public and International Affairs Research at American ...
Punishment can enhance performance, Nottingham academics find
2013-03-13
The stick can work just as well as the carrot in improving our performance, a team of academics at The University of Nottingham has found.
A study led by researchers from the University's School of Psychology, published recently in the Journal of Neuroscience, has shown that punishment can act as a performance enhancer in a similar way to monetary reward.
Dr Marios Philiastides, who led the work, said: "This work reveals important new information about how the brain functions that could lead to new methods of diagnosing neural development disorders such as autism, ADHD ...
Normal prion protein regulates iron metabolism
2013-03-13
An iron imbalance caused by prion proteins collecting in the brain is a likely cause of cell death in Creutzfeldt-Jakob disease (CJD), researchers at Case Western Reserve University School of Medicine have found.
The breakthrough follows discoveries that certain proteins found in the brains of Alzheimer's and Parkinson's patients also regulate iron. The results suggest that neurotoxicity by the form of iron, called redox-active iron, may be a trait of neurodegenerative conditions in all three diseases, the researchers say.
Further, the role of the normal prion protein ...