Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China.
Guangdong Key Laboratory of Environmental Pollution and Health, School of Environment, Jinan University, Guangzhou 510632, China.
J Hazard Mater. 2023 Jan 5;441:129831. doi: 10.1016/j.jhazmat.2022.129831. Epub 2022 Aug 24.
The contagious coronavirus disease-2019 pandemic has led to an increasing number of disposable face masks (DFMs) abandoned in the environment, when they are exposed to the air condition, the broken of chemical bond induced aging is inevitably occurred which meantime would cause a drastic decrease of the mechanical flexibility. However, the understanding of between chemical bond change related to aging and its micromechanical loss is limited due to the lack of refined techniques. Herein, the atomic force microscopy (AFM) technique was firstly used to observe the aging process induced by methine of the polypropylene-based DFMs. By comparing the micromechanical properties loss, the influences of humidity and light density on the DFM aging were systematically studied in the early 72 h, and it revealed that the increasing scissions number of the easiest attacked methine (C-H) can gradually decrease the micromechanical properties of the polypropylene (PP)-based DFM. Furthermore, the results are also validated by the in- situ FTIR and XPS analysis. This work discloses that an aging process can be initially estimated with the micromechanical changes observed by AFM, which offers fundamental data to manage this important emerging plastic pollution during COVID-19 pandemic.
传染性冠状病毒病 2019 大流行导致越来越多的一次性口罩（DFM）在暴露于空气中时被丢弃在环境中，当它们暴露于空气中时，化学键的断裂不可避免地会导致老化，同时会导致机械柔韧性急剧下降。然而，由于缺乏精细技术，对与老化相关的化学键变化及其微观力学损失的理解是有限的。在此，首次使用原子力显微镜（AFM）技术观察了基于聚丙烯的 DFM 中亚甲基引发的老化过程。通过比较微机械性能的损失，系统研究了湿度和光密度对 DFM 老化的影响在最初的 72 小时内，结果表明，最易受攻击的亚甲基（C-H）的交联数增加，可逐渐降低基于聚丙烯（PP）的 DFM 的微机械性能。此外，原位傅里叶变换红外光谱（FTIR）和 X 射线光电子能谱（XPS）分析也验证了这一结果。这项工作揭示了可以通过 AFM 观察到的微机械变化初步估计老化过程，这为管理 COVID-19 大流行期间这种重要的新兴塑料污染提供了基础数据。
