Release Behavior of Liquid Crystal Monomers from Waste Smartphone Screens: Occurrence, Distribution, and Mechanistic Modeling

作者：Jin, Qianqian; Yu, Jianxin; Fan, Yinzheng; Zhan, Yuting; Tao, Danyang; Tang, Jingchun; He, Yuhe^*

来源：Environmental Science and Technology, 2023, 57(28): 10319-10330.

DOI：10.1021/acs.est.2c09602

• liquid crystals monomers
• emission factor
• diffusion-partitioning
• environmental modeling
• release mechanism

Thediffusion-partitioning behaviors of LCMs released fromvarious components of waste smartphone screens were modeled. The proposedrelease pathways and mechanisms provide valuable insights into theenvironmental transport behavior and fate of LCMs. @@@ Liquid crystal display (LCD) screens can release manyorganic pollutantsinto the indoor environment, including liquid crystal monomers (LCMs),which have been proposed as a novel class of emerging pollutants.Knowing the release pathways and mechanisms of LCMs from various componentsof LCD screens is important to accurately assess the LCM release andreveal their environmental transport behavior and fate in the ambientenvironment. A total of 47, 43, and 33 out of 64 target LCMs weredetected in three disassembled parts of waste smartphone screens,including the LCM layer (LL), light guide plate (LGP), and screenprotector (SP), respectively. Correlation analysis confirmed LL wasthe source of LCMs detected in LGP and SP. The emission factors ofLCMs from waste screen, SP, and LGP parts were estimated as 2.38 x10(-3), 1.36 x 10(-3), and 1.02x 10(-3), respectively. A mechanism model wasdeveloped to describe the release behaviors of LCMs from waste screens,where three characteristics parameters of released LCMs, includingaverage mass proportion (AP), predicted subcooled vapor pressures(P (L)), and octanol-air partitioningcoefficients (K (oa)), involving coexistenceof absorption and adsorption mechanisms, could control the diffusion-partitioning.The released LCMs in LGP could reach diffusion-partition equilibriummore quickly than those in SP, indicating that LCM release could bemainly governed through SP diffusions.

• 单位
  南开大学