Insight into chain scission and release profiles from photodegradation of polycarbonate microplastics

Non-Negligible Effects of UV Irradiation on Transformation and Environmental Risks of Microplastics in the Water Environment

“…The surface morphology of microfibers changed after UV light and cracked to produce smaller particles in the marine environment [ 39 ]. UV irradiation and mechanical wear promote the fracture and photo-oxidation of polycarbonate MPs (PC-MPs) [ 40 ]. The above research results all proved that photo-degradation is an important source of MPs in the ecosystem, and photo-chemically induced brittleness can lead to the formation and release of small particles from plastics [ 37 , 41 ].…”

“…UV aging significantly affected the physical and chemical properties of PE, which included an increase in hydrophilicity and crystallinity, reduction in average particle size and introduction of oxygen-containing functional groups [ 47 ]. Photoaging is mainly dominated by the generation of reactive oxygen species (ROS) in the environmental media [ 40 ]. The molecular weight decrease in plastics caused by photo-induced oxidation and the formation of oxygen-containing functional groups such as carboxyl, hydroxyl and carbonyl groups make the materials more brittle and increase the possibility of bio-degradation and mechanical degradation [ 34 , 51 ].…”

“…and additives (bisphenol A, butylbenzene sulfonamide, triphenyl phosphate, diphenylmethyl, etc.) were detected in the seawater leachate of microfibers during the photoaging process [ 40 ].…”

Progress on the photo aging mechanism of microplastics and related impact factors in water environment

“…此外，水环境中的塑料添加剂也能通过影响氧化应激反应 (AREc32)、雌激素介导受体效应、激活代谢酶等形式对生物体的细胞或组织产 生相应的毒性效应 [71] . Shi 等人 [43] 太阳光下，而小粒径的微塑料颗粒容易在水流的机械力作用下不断翻滚，导致多 个平面均受到光照影响，进一步验证了粒径在微塑料老化过程中的重要作用 [29] 。 此外，微塑料颗粒在水中的翻滚过程也一定程度上阻止了生物膜的形成。综上所 述，微塑料颗粒在老化过程中可能比大颗粒塑料碎片具有更高的老化速率 [31] .…”

The Proposal and Necessity of the Numerical Description of Nano- and Microplastics’ Surfaces (Plastisphere)

“…Naturally occurring fragmentation due to the UV light or mechanical and chemical interactions is further supported by the microbial degradation; for instance, poly(ethylene terephthalate) (PET) decomposed under alkaline conditions had a diameter that diminished from 7.3 to 1.58 µm [ 13 ]. The ageing of polycarbonate due to photodegradation leads to a decline in molecular weight and leaching of toxic compounds [ 14 ]. The gradual cutting of the carbon chain and formation of reactive oxygen species (singlet oxygen, hydroxyl radical, superoxide anion radical) are caused by the exposition to UV radiation.…”