Engineered nanomaterials are new synthetic chemical products that offer promise as enabling components in next-generation environmental technologies, but may also pose health risks of their own through unintended exposure. Project 4 in the Brown SRP uses modern methods of nano-synthesis to create, characterize, and formulate new nanomaterials, and to explore their applications and implications for environmental health.
Currently, Project 4 is pursuing the development of advanced environmental barrier technologies that prevent human exposure to toxic chemicals using graphene, a new atomically-thin, sheet-like nanomaterial. We are fabricating and testing high-performance graphene-based environmental barriers for preventing the release and transport of vapor toxicants, and are exploring graphene encapsulation as an effective strategy for mitigating the toxicity of nanoparticles in human health applications. A team of toxicologists (from Project 2) and engineers (from Project 4) are working together to understand how graphene materials and graphene-based products can be designed to be both functional and also safe for human use.
Graphene materials are natural choices for the next generation of barrier technologies. Their impermeable, two-dimensional, space-filling geometry blocks the transport of all known molecules, while their atomic-scale thickness offers the potential for achieving those barrier properties with ultra-low mass loadings and low cost. Project 4 personnel are fabricating tiled, multilayer graphene oxide-based barrier films for containing mercury and trichloroethylene as model vapor toxicants and are assessing the potential to create molecular-sieving selective barriers that exclude target toxicants found in mixtures.
This project is also assessing the safety of graphene and other emerging 2D materials if they were to be inhaled by manufacturing workers in a tiered toxicity testing approach spanning Projects 2 and 4. We hypothesize that lateral dimension and surface chemistry are the primary determinants of graphene material toxicity. Project 4 personnel are creating and characterizing a panel of 2D nanomaterials, and will use in vitro methods to study their biological reactivity, biodegradability and persistence, and their flexibility or stiffness in their interaction with biological tissue. Finally, most nanomaterials are not used in pure form, but as formulated composites or hybrids. Project 4 is collaborating with Project 2 to fabricate metal-graphene hybrid materials and study their cellular uptake and toxicity pathways as models for the complex exposures occurring in nanotechnology practice. Our integrated approach to nanotechnology applications and safety strives to create new environmental technologies, while ensuring their responsible development informed by data on nanomaterial hazard.
- To synthesize and characterize a panel of 2D nanomaterials and hybrids as components in environmental barrier technologies (Aim 2) and as models and case studies for the biological effects studies (Aim 3).
- To design, fabricate, and evaluate graphene-based barriers for the containment of vapor toxicants.
- To investigate the chemical pathways through which graphene and other 2D material surfaces mediate toxic responses.
Robert Hurt, Ph.D.