Researchers at NYU Abu Dhabi have created a new process that can convert polyethylene-based plastic bags and polypropylene-based surgical masks into carbon dots.
This innovative method is organic solvent-free and can be completed in a single step. It addresses the pressing issue of pandemic-related plastic waste, which has resulted in approximately 26,000 metric tons of waste ending up in the oceans. Finding efficient ways to upcycle this non-degradable material has become even more urgent. By transforming single-use plastic into carbon dots, which are biocompatible carbon nanomaterials, various applications can be explored, such as biological imaging, environmental monitoring, chemical analysis, targeted drug delivery, disease diagnosis and therapy, and anti-counterfeiting. Unlike existing methods that involve multiple steps and the use of toxic chemicals, this new approach offers a simpler and safer solution.
In the journal Green Chemistry, a study titled "High-yield, One-pot Upcycling of Polyethylene and Polypropylene Waste into Blue-Emissive Carbon Dots" introduces a new synthesis method that efficiently transforms plastic waste into valuable carbon dots. This approach is not only simple and cost-effective but also highly scalable, allowing for large-scale upcycling of plastic waste. A noteworthy aspect of this method is its ability to handle plastics contaminated with organic waste, such as food scraps, which presents a significant challenge for traditional recycling methods. The senior author of the study is Khalil Ramadi, an Assistant Professor of Bioengineering at NYUAD, while the first authors are Mohammed Abdelhameed, a scientist at NYUAD, and Mahmoud Elbeh, an undergraduate student at NYUAD.
Furthermore, the researchers conducted an economic analysis to assess the viability of this synthetic method. They compared the variable costs of the process to existing chemical recycling methods and considered the economic value of the resulting carbon dots. The findings revealed a promising outlook, with the global market value of carbon dots projected to reach $6.412 billion U.S. dollars by 2025, a significant increase from $2.496 billion in 2019. This substantial commercial value justifies the associated processing costs and demonstrates the economic feasibility of the new method.
The extensive usage of single-use plastics, especially surgical masks and medical waste, during the pandemic has heightened the urgency of finding a solution to manage non-biodegradable waste. Moreover, it is estimated that only 14 percent of eligible plastic packaging, which has seen a surge in usage due to online shopping, undergoes recycling, while the rest is disposed of in landfills and oceans, causing significant harm. These materials can be ingested by organisms or fragmented into micro- and nano-plastics, posing threats to terrestrial, marine, and freshwater ecosystems, ultimately endangering human health.
Ramadi emphasized the significance of the newly developed method, stating, "Our team has successfully created a cost-effective and safe approach that can be readily implemented to substantially reduce the release of harmful plastic into our ecosystems. Apart from safeguarding our ecosystems, this method allows for the efficient and responsible production of carbon dots, a versatile nanotechnology with limitless potential applications."
Elbeh expressed enthusiasm for supporting the UAE's Circular Economy Policy and emphasized the value of their project. He said, "We are thrilled to contribute to tackling the plastic waste crisis by generating a valuable product through a relatively straightforward method. We look forward to collaborating further to not only scale up this project but also explore additional developments and applications utilizing the produced carbon dots.
More information: Mohammed Abdelhameed et al, High-yield, one-pot upcycling of polyethylene and polypropylene waste into blue-emissive carbon dots, Green Chemistry (2023). DOI: 10.1039/D2GC04177D. Journal information: Green Chemistry