Wen's Research Group
ROS-mediated photoaging pathways of nano- and micro-plastic particles under UV irradiation
Explore the Nano World
Following the previous paper on microplastics and BPA release from UV-aged plastic bottles, (https://doi.org/10.1021/acs.est.1c05812), Prof. Li Yang’s group at Beijing Normal University, recently published another paper (https://doi.org/10.1016/j.watres.2022.118320) in Water Research, which investigated the effects of surface coatings, polymer types and grain sizes on ROS generation and photoaging intermediates. Bare polystyrene (PS) NPs generated hydroxyl radicals (•OH) and singlet oxygen (1O2), while coated PS NPs (carboxyl-modified PS (PS-COOH), amino-modified PS (PS-NH2)) and PS MPs generated fewer ROS due to coating scavenging or size effects. Polypropylene, polyethylene, polyvinyl chloride, polyethylene terephthalate and polycarbonate MPs only generated •OH. For aromatic polymers, •OH addition preferentially occurred at benzene rings to form monohydroxy polymers. Excess •OH resulted in H abstraction, C-C scission and phenyl ring opening to generate aliphatic ketones, esters, aldehydes, and aromatic ketones. For coated PS NPs, •OH preferentially attacked the surface coatings to result in decarboxylation and deamination reactions. For aliphatic polymers, •OH attack resulted in the formation of carbonyl groups from peracid, aldehyde or ketone via H abstraction and C-C scission. Moreover, 1O2 might participate in phenyl ring opening for PS NPs and coating degradation for coated PS NPs. This study facilitates our understandings of the ROS-induced weathering process of NPs/MPs under UV irradiation.
Wen Zhang, Ph.D., P.E., BCEE
Principal Investigator
Professor
Phone: (973) 596-5520
Fax: (973) 596-5790
Email: wen.zhang@njit.edu
Office Location: Colton Hall 211
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