Surface Reactions in Selective Modification: The Prerequisite for Plastic Flotation
Surface Reactions in Selective Modification: The Prerequisite for Plastic Flotation
复制标题
选择性改性中的表面反应：塑料浮选的先决条件
DOI：
10.1021/acs.est.9b07861
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Hui Wang
中科院分区：
文献类型：
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作者：
Hongru Jiang;Yingshuang Zhang;Hui Wang
废塑料处置不当造成了很大的环境污染，但塑料回收可以通过源头控制减少环境中新增和残留废塑料的数量。塑料浮选可以分离具有相似物理和化学性质的废旧塑料，这表明其在塑料回收方面具有广阔的应用前景。借助不同的亲水性，可以通过浮选来分离废旧塑料，并可以通过表面改性来实现亲水化。然而，尚未发表针对这些表面反应的系统研究，而此类修饰是塑料浮选的先决条件。在这篇批判性综述中，我们不仅总结了各种改性机制，包括物理调节、表面氧化、表面降解、脱氯和涂层，而且还合理地为一些反应添加了额外信息，包括表面重建、塑料降解、聚合物稳定性、废水处理、土壤修复和塑料化学回收。还提出了一个全新的概念“可塑基因”来阐述一些相互矛盾的结果。具有明显表面反应的塑料浮选可以促进塑料回收，从而从源头上控制废塑料，节省能源，减少微塑料。我们还预测清洁、高效、实用的表面改性和塑料浮选面临的挑战。
Improper disposal of waste plastic has caused much environmental pollution, but plastic recycling can reduce the amount of new and residual waste plastic in the environment through source control. Plastic flotation can separate waste plastics with similar physical and chemical properties, which suggests its promising application in plastic recycling. With the help of the different hydrophilicities waste plastic can be separated by flotation, and hydrophilization can be accomplished by surface modifications. However, no systematic studies addressing these surface reactions have been published yet, and such modifications are a prerequisite for plastic flotation. In this critical review, we not only summarize the various modification mechanisms, including physical regulation, surface oxidation, surface degradation, dechlorination, and coating, but also have reasonably added additional information for some reactions covering surface reconstruction, plastic degradation, polymer stability, wastewater treatment, soil remediation, and chemical recycling of plastic. An entirely novel concept, the “plastic gene”, is also proposed to elaborate on some contradictory results. Plastic flotation with clear surface reactions may promote plastic recycling and thereby control waste plastic at the source, save energy, and reduce microplastics. We also predict challenges for clean, efficient, and practical surface modifications and plastic flotation.