Flashing plastic ash completes recycling
Rice lab's turns pyrolyzed ash into graphene for improving concrete, other compounds
2021-01-13
(Press-News.org) HOUSTON - (Jan. 13, 2021) - Pyrolyzed plastic ash is worthless, but perhaps not for long.
Rice University scientists have turned their attention to Joule heating of the material, a byproduct of plastic recycling processes. A strong jolt of energy flashes it into graphene.
The technique by the lab of Rice chemist James Tour produces turbostratic graphene flakes that can be directly added to other substances like films of polyvinyl alcohol (PVA) that better resist water in packaging and cement paste and concrete, dramatically increasing their compressive strength.
The research appears in the journal Carbon.
Like the flash graphene process the lab introduced in 2019, pyrolyzed ash turns into turbostratic graphene. That has weaker attractive interactions between the flakes, making it easier to mix them into solutions.
Last October, the Tour lab reported on a process to convert waste plastic into graphene. The new process is even more specific, turning plastic that is not recovered by recycling into a useful product.
"This work enhances the circular economy for plastics," Tour said. "So much plastic waste is subject to pyrolysis in an effort to convert it back to monomers and oils. The monomers are used in repolymerization to make new plastics, and the oils are used in a variety of other applications. But there is always a remaining 10% to 20% ash that's valueless and is generally sent to landfills.
"Now we can convert that ash into flash graphene that can be used to enhance the strength of other plastics and construction materials," he said.
Pyrolysis involves heating a material to break it down without burning it. The products of pyrolyzed, recycled plastic include energy-rich gases, fuel oils, waxes, naphtha and virgin monomers from which new plastic can be produced.
But the rest -- an estimated 50,000 metric tons in the United States per year -- is discarded.
"Recyclers do not turn large profits due to cheap oil prices, so only about 15% of all plastic gets recycled," said Rice graduate student Kevin Wyss, lead author of the study. "I wanted to combat both of these problems."
The researchers ran a pair of experiments to test the flashed ash, first mixing the resulting graphene with PVA, a biocompatible polymer being investigated for medical applications, fuel cell polymer electrolyte membranes and environmentally friendly packaging. It has been held back by the base material's poor mechanical properties and vulnerability to water.
Adding as little as 0.1% of graphene increases the amount of strain the PVA composite can handle before failure by up to 30%, they reported. It also significantly improves the material's resistance to water permeability.
In the second experiment, they observed significant increases in compressive strength by adding graphene from ash to Portland cement and concrete. Stronger concrete means less concrete needs to be used in structures and roads. That curtails energy use and cuts pollutants from its manufacture.
INFORMATION:
Co-authors of the study are Rice graduate students Jacob Beckham, Weiyin Chen and Prabhas Hundi and postdoctoral researcher Duy Xuan Luong, and Shivaranjan Raghuraman and Rouzbeh Shahsavari of C-Crete Technologies.
The National Science Foundation, the Air Force Office of Scientific Research and the Department of Energy supported the research.
Read the abstract at https://www.sciencedirect.com/science/article/abs/pii/S0008622320312409.
This news release can be found online at https://news.rice.edu/2021/01/13/flashing-plastic-ash-completes-recycling/
Follow Rice News and Media Relations via Twitter @RiceUNews.
Related materials:
Tour Group: http://www.jmtour.com
Department of Chemistry: https://chemistry.rice.edu
Wiess School of Natural Sciences: https://naturalsciences.rice.edu
Images for download:
https://news-network.rice.edu/news/files/2021/01/0118_PYRO-1-WEB.jpg
Rice University chemists turned otherwise-worthless pyrolyzed ash from plastic recycling into graphene through a Joule heating process. The graphene could be used to strengthen concrete and toughen plastics used in medicine, energy and packaging applications. (Credit: Tour Group/Rice University)
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,978 undergraduates and 3,192 graduate students, Rice's undergraduate student-to-faculty ratio is just under 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for lots of race/class interaction and No. 1 for quality of life by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance.
Jeff Falk
713-348-6775
jfalk@rice.edu
Mike Williams
713-348-6728
mikewilliams@rice.edu
[Attachments] See images for this press release:
ELSE PRESS RELEASES FROM THIS DATE:
2021-01-13
CHAMPAIGN, Ill. -- A dramatic decline in bees and other pollinating insects presents a threat to the global food supply, yet it's getting little attention in mainstream news.
That's the conclusion of a study from researchers at the University of Illinois Urbana-Champaign, published this week in a special issue of the Proceedings of the National Academy of Sciences. The study was based on a search of nearly 25 million news items from six prominent U.S. and global news sources, among them The New York Times, The Washington Post and The Associated Press.
The study found "vanishingly low levels of attention to pollinator population topics" over several decades, even compared with ...
2021-01-13
Wetlands are the dominant natural source of atmospheric methane, a potent greenhouse gas which is second only to carbon dioxide in its importance to climate change. Anthropogenic climate change is expected to enhance methane emissions from wetlands, resulting in further warming. However, wetland methane feedbacks were not fully assessed in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, posing a challenge to meeting the global greenhouse gas mitigation goals set under the Paris Agreement.
To understand how wetland methane cycling may evolve and drive climate feedbacks in the future, scientists are increasingly looking to Earth's past.
"Ice core records indicate ...
2021-01-13
People worldwide want their coffee to be both satisfying and reasonably priced. To meet these standards, roasters typically use a blend of two types of beans, arabica and robusta. But, some use more of the cheaper robusta than they acknowledge, as the bean composition is difficult to determine after roasting. Now, researchers reporting in ACS' Journal of Agricultural and Food Chemistry have developed a new way to assess exactly what's in that cup of joe.
Coffee blends can have good quality and flavor. However, arabica beans are more desirable than other types, resulting in a higher market value for blends containing a higher proportion of this variety. In some cases, producers dilute their blends with the less expensive robusta beans, yet that is hard for consumers ...
2021-01-13
DURHAM, N.C. -- Biomedical engineers at Duke University have devised an algorithm to remove contaminated microbial genetic information from The Cancer Genome Atlas (TCGA). With a clearer picture of the microbiota living in various organs in both healthy and cancerous states, researchers will now be able to find new biomarkers of disease and better understand how numerous cancers affect the human body.
In the first study using the newly decontaminated dataset, the researchers have already discovered that normal and cancerous organ tissues have a slightly different microbiota composition, that bacteria from these diseased sites can enter the bloodstream, and that this bacterial information could help diagnose ...
2021-01-13
Liver transplant priority in the U.S. goes to the sickest patients, which fails to consider other important factors, including how long patients are likely to survive post-transplant.
Researchers with Sylvester Comprehensive Cancer Center at the University of Miami Miller School of Medicine are collaborating with faculty at the University of Pennsylvania to develop a risk score that more comprehensively prioritizes liver cancer patients for transplantation.
Their paper documenting the development and validation of the LiTES-HCC score to predict post-transplant survival for hepatocellular carcinoma, or liver cancer, patients was published in the highly respected peer-reviewed Journal of Hepatology.
The ...
2021-01-13
Egg cells are among the largest cells in the animal kingdom. If moved only by the random jostlings of water molecules, a protein could take hours or even days to drift from one side of a forming egg cell to the other. Luckily, nature has developed a faster way: cell-spanning whirlpools in the immature egg cells of animals such as mice, zebrafish and fruit flies. These vortices enable cross-cell commutes that take just a fraction of the time. But until now, scientists didn't know how these crucial flows formed.
Using mathematical modeling, researchers now have an answer. The gyres result from the collective behavior of rodlike molecular ...
2021-01-13
Many students, especially non-science majors, dread chemistry. The first lesson in an introductory chemistry course typically deals with how to interpret the periodic table of elements, but its complexity can be overwhelming to students with little or no previous exposure. Now, researchers reporting in ACS' Journal of Chemical Education introduce an innovative way to make learning about the elements much more approachable -- by using "pseudo" periodic tables filled with superheroes, foods and apps.
One of the fundamental topics taught in first-year undergraduate chemistry courses is ...
2021-01-13
WASHINGTON -- In a new study, researchers show that a light-based analytical technique known as Raman spectroscopy could aid in early detection of oral squamous cell carcinoma (OSCC).
OSCC is the most prevalent type of oral cancer and ranks among the most common cancers diagnosed worldwide. Although effective treatments are available, the cancer is often not detected until a late stage, resulting in overall poor prognosis.
"Raman spectroscopy is not only label-free and non-invasive, but it can potentially be used in ambient light conditions," says research team leader Levi Matthies from University Medical Center Hamburg-Eppendorf in Germany. "This makes it promising for use as a potential screening tool ...
2021-01-13
Cardiovascular Innovations and Applications, publishes selected abstracts from the 31st Great Wall International Cardiology (GW-ICC) Conference, October 19 - 25, 2020
Beijing, January 13, 2021: Cardiovascular Innovations and Applications (CVIA), in its role as the official journal of the Great Wall International Cardiology Conference (GW-ICC), has published selected abstracts from the 31st GW-ICC. Abstracts are now online at https://www.ingentaconnect.com/content/cscript/cvia/2020/00000005/a00101s1/art00001
Co-Editors-in-Chief of CVIA Dr. C. Richard Conti, past president of the American College of Cardiology, and Dr Jianzeng Dong, Capital Medical University, Beijing, China commented that CVIA is delighted to be ...
2021-01-13
Thousands of genetic markers have already been robustly associated with complex human traits, such as Alzheimer's disease, cancer, obesity, or height. To discover these associations, researchers need to compare the genomes of many individuals at millions of genetic locations or markers, and therefore require cost-effective genotyping technologies. A new statistical method, developed by Olivier Delaneau's group at the SIB Swiss Institute of Bioinformatics and the University of Lausanne (UNIL), offers game-changing possibilities. For less than $1 in computational cost, GLIMPSE is able to statistically infer a complete human genome from a very small amount of data. The method offers ...
LAST 30 PRESS RELEASES:
[Press-News.org] Flashing plastic ash completes recycling
Rice lab's turns pyrolyzed ash into graphene for improving concrete, other compounds
