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Determining the release of carbon nanotubes from CNT-polymer composites during accelerated weathering
Citation:
Sahle-Demessie, E. AND C. Han. Determining the release of carbon nanotubes from CNT-polymer composites during accelerated weathering. American Chemical Society Fall 2018 Natinal Meeting and Exposition, Boston, MA, August 19 - 23, 2018.
Impact/Purpose:
Elucidating the long term environmental impact of nanomaterials-enabled consumer products depends upon the nature and toxicity of fragments released as a consequence of weathering. To address this question polypropylene and epoxy containing carbon based nanomaterials-CNT, graphene- were exposed to accelerated weathering. Nanomaterials and polymer fragments released after selected exposure periods were collected, analyzed and their toxicity were tested. The study characterizes the relationship of nanorelease with ageing conditions and identifies the biological impacts of released materials.
Description:
Engineered nanoparticles are increasingly incorporated in a wide variety of polymeric materials with favorable matrix-filler interactions that resulted in improved physical, chemical, and electrical properties. Environmental weathering and the potential release of carbon nanotubes (CNTs) from composite matrices becomes a concern as a high volume application of nanocomposite is coming real. It is essential to understand the relationship between the inherent characteristics of nanocomposite based consumer products and the likelihood of the release of nanomaterials throughout the life-cycle of the product. In the present study nanocomposite films and wafers of polyolefins, polyimide and epoxy were exposed to accelerated weathering conditions. The changes in the physical, chemical, and structural properties of these composites and their potential for the release of nanomaterials were investigated. Pristine and CNT-added polymer film were aged in a weathering chamber that simulated UV exposure, humidity and rain cycles. The role of chemical nature of polymer, film thickness, and exposure condition were correlated with the degradation and release of CNTs. The weathered samples were characterized by SEM, TEM, DSC, TGA, XRD, FTIR and optical microscopy techniques The release of CNTs from polymer-CNT composite were measured using dynamic light scattering and single particle-ICP-MS. The results of the characterization and nanoparticle release as well as the toxicity of the release nanoparticles will be discussed in this presentation.