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Detection, and toxicity of nanomaterials and fragments released from consumer products.
Citation:
Sahle-Demessie, E., A. Zhao, C. Han, AND E. Varughese. Detection, and toxicity of nanomaterials and fragments released from consumer products. American Chemical Society Annual meeting, Cincinnati,OH, August 17 - 20, 2020.
Impact/Purpose:
Results of the release of nanoparticles from the aging of nano enabled materials. Aging and release of nanomaterials from epoxy-based composites and toxicity of released materials based on in-vitro assessment of toxicity.
Description:
Nanomaterials are applied in many consumer products: paints, coatings, composites, and food packing materials. In this study, epoxy and polypropylene filled with different nano additives were aged in an accelerated weathering chamber that simulates cycles of solar irradiation and rainfall. Aged plates were taken out at selected times to evaluate the effects of weathering. The changes in physicochemical properties modulated by the type of polymer matric and nano-additive were investigated. The results revealed that surface oxidation increased in crystallinity, causing the surface to brittle during the weathering process. This loose of elasticity resulted in a craze and cracks formation and further degradation of the thinner samples. Oxidation penetrated selectively into the polymer structure. Cracks were reduced by the presence of carbon nanotube (CNT) at high content showed less loss of surface hardness, fewer cracks, and better hydrophobicity on the weathered surface than other groups, confirming its functions of stabilization and antioxidation. Thermal analysis was an essential tool to measure the level of bulk material oxidation. Carbonyl indices were determined based on the surface FTIR absorbance of aging plates. When the aged PP, and PP-MWCNT were placed in sonication water-bath fragments of polymer, CNT and metals were released. The release of nanomaterials from the composites was investigated with high-resolution transmission microscopy (HR-TEM), dynamic light scattering (DLS), and single particle-inductively coupled plasma (SP-ICP) analysis. The metal ions in free MWCNTs were quantified with a single particle-ICP analysis. Lastly, the toxicity of released particles was investigated.