Abstract The increased use of polymer nanocomposites in different applications could lead to potential nanofiller release into different human and environmental compartments and consequently, increase the exposure of human and environmental species to nanomaterials. This study aims at determining how the inclusion of nanofillers with diverse chemical nature (SiO2, TiO2, ZnO, multiwalled carbon nanotubes and two nano-organoclays) in polyamide 6 composites influences the nanomaterial release during the use of these products. The different nanocomposites were exposed to accelerated ageing processes, simulating outdoor conditions, through irradiation with UV light under a combination of dry-wet cycles. Release monitoring consisted of nanocomposites characterisation, run-off waters collection and released materials quantification and characterisation. The study confirmed that the chemical surface nature of the nanofiller strongly impacts on polymer degradation, in some cases enhancing its protection and in others promoting polyamide hydrolysis and/or photo-degradation processes. Polymer degradation and nanomaterial-polymer compatibility are the main determinants for the release and consequent exposure to nanofillers.

中文翻译：

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PA6纳米复合材料在模拟户外使用的气候条件下的释放机制

摘要 在不同应用中增加聚合物纳米复合材料的使用可能导致潜在的纳米填料释放到不同的人类和环境隔间中，从而增加人类和环境物种对纳米材料的暴露。本研究旨在确定在聚酰胺 6 复合材料中加入具有不同化学性质的纳米填料（SiO2、TiO2、ZnO、多壁碳纳米管和两种纳米有机粘土）如何影响这些产品在使用过程中的纳米材料释放。不同的纳米复合材料暴露于加速老化过程，模拟室外条件，通过在干湿循环组合下用紫外线照射。释放监测包括纳米复合材料表征、径流水收集和释放材料量化和表征。该研究证实，纳米填料的化学表面性质强烈影响聚合物降解，在某些情况下增强其保护，而在其他情况下促进聚酰胺水解和/或光降解过程。聚合物降解和纳米材料-聚合物相容性是释放和随后暴露于纳米填料的主要决定因素。