Despite the fact that nanomaterials are considered potentially hazardous in a freely dispersed form, they are often considered safe when encapsulated into a polymer matrix. However, systematic research to confirm the abovementioned paradigm is lacking, despite the potential risks of nanomaterials to human health and the environment. Our data indicates that there are possible mechanisms of nanomaterial release from nanocomposites due to exposure to environmental conditions, especially UV radiation. The degradation of the polymer matrix and potential release of nanomaterials depend on the nature of the nanofillers and the polymer matrix, as well as on the nature of environmental exposure, such as the combination of UV, moisture, mechanical stress and other factors. To the best of our knowledge there is no single study which addresses all these effects. We present here an initial study of the stability of nanocomposites exposed to environmental conditions, where carbon nanotube (CNT) containing composites were evaluated with various spectroscopic and microscopic techniques. This work discusses various mechanisms of degradation, including such factors as UV, moisture and mechanical damage. We also investigated the toxicological effects of the released materials, including several scenarios ranging from toxicity of nanofillers partially covered with polymers to completely unprotected nanomaterials. The effects of nanomaterial exposure were determined using an in vitro tissue culture model as well as an in vivo Drosophila model. In addition to developing new paradigms in terms of safety of nanocomposites, the outcomes of this research can lead to recommendations on safer design strategies for the next generation of CNTs containing products.
Citation: Science of the Total Environment
Pub Type: Journals
CNT-epoxy nanocomposites, Environmental degradation, Degradation products, Nanomaterials release, Nanoparticle toxicity