Transforming e-waste into a strong, protective coating for metal

July 29, 2020

A typical recycling process converts large quantities of items made of a single material into more of the same. However, this approach isn't feasible for old electronic devices, or "e-waste," because they contain small amounts of many different materials that cannot be readily separated. Now, in ACS Omega, researchers report a selective, small-scale microrecycling strategy, which they use to convert old printed circuit boards and monitor components into a new type of strong metal coating.

In spite of the difficulty, there's plenty of reason to recycle e-waste: It contains many potentially valuable substances that can be used to modify the performance of other materials or to manufacture new, valuable materials. Previous research has shown that carefully calibrated high temperature-based processing can selectively break and reform chemical bonds in waste to form new, environmentally friendly materials. In this way, researchers have already turned a mix of glass and plastic into valuable, silica-containing ceramics. They've also used this process to recover copper, which is widely used in electronics and elsewhere, from circuit boards. Based on the properties of copper and silica compounds, Veena Sahajwalla and Rumana Hossain suspected that, after extracting them from e-waste, they could combine them to create a durable new hybrid material ideal for protecting metal surfaces.

To do so, the researchers first heated glass and plastic powder from old computer monitors to 2,732 F, generating silicon carbide nanowires. They then combined the nanowires with ground-up circuit boards, put the mix on a steel substrate then heated it up again. This time the thermal transformation temperature selected was 1,832 F, melting the copper to form a silicon-carbide enriched hybrid layer atop the steel. Microscope images revealed that, when struck with a nanoscale indenter, the hybrid layer remained firmly affixed to the steel, without cracking or chipping. It also increased the steel's hardness by 125%. The team refers to this targeted, selective microrecycling process as "material microsurgery," and say that it has the potential to transform e-waste into advanced new surface coatings without the use of expensive raw materials. 
-end-
The authors acknowledge funding from the Australian Research Council's Australian Laureate Fellowship.

The article is freely available as an ACS AuthorChoice article here.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS' mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and its people. The Society is a global leader in providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a specialist in scientific information solutions (including SciFinder® and STN®), its CAS division powers global research, discovery and innovation. ACS' main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive press releases from the American Chemical Society, contact newsroom@acs.org.

Follow us: Twitter | Facebook

American Chemical Society

Related Copper Articles from Brightsurf:

New material 'mines' copper from toxic wastewater
A team of scientists led by Berkeley Lab has designed a new material -- called ZIOS (zinc imidazole salicylaldoxime) -- that targets and traps copper ions from wastewater with unprecedented precision and speed.

Team uses copper to image Alzheimer's aggregates in the brain
A proof-of-concept study conducted in a mouse model of Alzheimer's disease offers new evidence that copper isotopes can be used to detect the amyloid-beta protein deposits that form in the brains of people living with -- or at risk of developing -- Alzheimer's.

Copper boosts pig growth, and now we know why
Pigs have better feed conversion rates with copper in their diets, but until now, scientists didn't fully understand why.

Cancer cells spread using a copper-binding protein
Researchers at Chalmers University of Technology, Sweden, have shown that the Atox1 protein, found in breast cancer cells, participates in the process by which cancer cells metastasise.

Adding copper strengthens 3D-printed titanium
Successful trials of titanium-copper alloys for 3D printing could kickstart a new range of high-performance alloys for medical device, defence and aerospace applications.

Matrix could ensure vital copper supplies
Researchers have identified a matrix of risks that the mining industry must overcome to unlock vitally important copper reserves.

Do microbes control the formation of giant copper deposits?
One of the major issues when studying ore deposits formed in surficial or near-surface environments is the relationship between ore-forming processes and bacteria.

Copper compound as promising quantum computing unit
Chemists at Friedrich Schiller University in Jena (Germany) have now synthesised a molecule that can perform the function of a computing unit in a quantum computer.

Copper ions flow like liquid through crystalline structures
Materials scientists have sussed out the physical phenomenon underlying the promising electrical properties of a class of materials called superionic crystals through the investigation of CuCrSe2.

A copper bullet for tuberculosis
Tuberculosis is a sneaky disease, and the number one cause of death from infectious disease worldwide.

Read More: Copper News and Copper Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.