Nanofillers are increasingly used for enhancing multiple properties of polymeric materials in many applications. However, polymers are susceptible to photodegradation by solar ultraviolet (UV) radiation Therefore, nanofillers in a polymer nanocomposite will eventually migrate and be released into the environments during their life cycles. Such release potentially poses an environmental health and safety problem and may present a roadblock to commercialization of these advanced materials. This study has investigated the fate and release of nanofillers from epoxy/nanosilica composites. Specially-designed cells containing nanocomposite specimens were irradiated with UV light in a well-controlled environmental chamber. UV irradiated samples were removed for measurements of polymer chemical degradation, mass loss, surface morphology, nanosilica accumulation on the composite surface, and nanosilica release. Epoxy matrix underwent rapid photodegradation, resulting in substantial accumulation of silica nanofillers on the composite surface and also release into the environment. A conceptual model for surface accumulation and release of nanosilica during UV irradiation of epoxy nanocomposites is presented.
Citation: Journal of Nanoscience and Nanotechnology
Pub Type: Journals
characterization, environment, nanoparticles, nanosilica, polymer, release, UV radiation, nanocomposites