Description
- Abstract:
- The widespread use of nanomaterials in established and emerging technologies will inevitably lead to human and environmental exposures that must be characterized and managed to ensure the safe development. This dissertation uses CuO nanoparticles as an example, and investigates the possible chemical transformation pathways, including particle dissolution, ion complexation, particle sulfidation, and the impacts of these transformation on nanoparticle’s stability, reactive oxygen species generation and cytotoxicity. This systematic study can help predict the fate and evaluate the potential adverse impacts of CuO nanoparticles released into biological and environmental systems. Nanoparticles are encapsulated inside crumpled graphene nanosacks, inspired by the atomically thin, conformable, and impermeable nature of graphene, which is expected to inhibit ion release and thus reduce toxicity. However, the crumpled nanosacks turn out to be open structure allowing rapid molecule exchange. In some cases, encapsulation is shown to enhance oxidation and dissolution rate of loaded nanoparticles. Though graphene nanosacks fail to detoxify nanoparticles, other fundamental behaviors are appealing including particle–particle electron transfer mediated by conductive graphene and anti-sintering property by inner walls. Another example utilizing the dimensionality of graphene-based architecture is textured graphene surface, which is fabricated by graphene oxide wet deposition onto pre-stretched elastomers followed by drying and relaxation. Multilayer graphene oxide films form periodic, delaminated buckle textures whose wavelengths and amplitudes can be systematically tuned by variation in the wet deposition process. Human and murine fibroblasts attach to these textured films and develop pronounced alignment and elongation relative to those on planar controls. The last part investigates the biological and environmental transformation of novel 2D nanomaterials beyond graphene. Very little is known about the potential implications of these emerging 2D nanomaterials. Because of the great chemical diversity in 2D materials, traditional toxicity testing methods will not be suitable for risk management or safe design across the entire material family. Here we evaluate simple theoretical models to screen and predict transformation and biological reactivity of 2D nanomaterials based on their fundamental chemical properties.
- Notes:
- Thesis (Ph.D. -- Brown University (2015)
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Citation
Wang, Zhongying,
"Biological and Environmental Transformations and Applications of Two-Dimensional Nanomaterials and Hybrids"
(2015).
Chemistry Theses and Dissertations.
Brown Digital Repository. Brown University Library.
https://doi.org/10.7301/Z0B27SQF
