Mechanisms of aging and release from weathered nanocomposites
Tinh Nguyen, Wendel Wohlleben, Li Piin Sung
Polymer nanocomposites are increasingly used in outdoor structures. However, polymers are susceptible to degradation by solar ultraviolet (UV) radiation, which potentially releases nanofiller during polymer nanocomposites life cycle. Such release may pose an environmental health and safety problem and may present a roadblock to commercialization of these advanced materials. This book chapter emphasizes on the mechanisms of aging and release of nanofillers during environmental exposures of polymer nancomposites. The paper includes four main parts: 1) critically examine the role of various nanofillers, e.g., carbon nanotubes, nanoclays, and metal oxides, on the photodegradation of polymer nanocompsoites, 2) present important case studies on the release of nanofiller from polymer nanocomposites exposed to UV radiation, 3) review recent advances in characterization metrologies of nanofiller release, and 4) present current understanding on the mechanisms of nanofiller surface accumulation and release due to degradation of polymer nanocomposites.
Safety of Nanomaterials along their Lifecycle: Release, Exposure and Human Hazards