EAGER: "Correlation of Explosibility and Dispersion Characteristics of Combustible Engineered Nanomaterials"

Texas A&M Engineering Experiment Station, College Station TX

Investigators

Abstract

CBET - 1321581 The fast growth in the production and use of nanomaterials has overcome the rate at which the hazards associated with these materials have been studied. While most of the studies on this aspect have been devoted for the understanding of nanomaterial toxicology resulted from workplace exposure, very little attention has been given to the fire and explosion hazards associated with combustible engineered nanomaterials. Thus, there is an urgent need for technical criteria from which the fire and explosion risk associated with combustible engineered nano materials can be quantified. Existing research on dust explosions hazards involving micro-sized dust materials have concluded that the severity of a confined dust explosion could increase as the particle size decreases to a certain level after which the particle size has no significant effect. As the result, there are many uncertainties that prevent making generalized conclusions that explains the behaviors of both micro and nano sized particles in dust explosion phenomenon. Therefore, thorough understanding will bring forward BROADER IMPACTS leading to the development of comprehensive experimental and theoretical information for supporting regulations and risk analysis for the use and production (intended/unintended) of nanomaterials. In this study, commercially available metallic and non-metallic combustible engineered nanomaterials, together with their micro-scale counterparts, will be investigated. The conventional explosibility characteristics, essential in determining the likelihood and severity of a dust explosion, of these nanomaterials in terms of minimum explosive concentration (MEC), maximum pressure (Pmax), maximum pressure increase rate ([dP/dt]max), and minimum ignition temperature (MIT) will be evaluated experimentally. Further, because nanomaterials have propensity to agglomerate; and because the degree of agglomeration have a significant effect on the explosion behavior, it is critical to have a complete understanding of the dispersion and agglomeration behavior of nanomaterials and determine the relationship between the corresponding particle diameter and surface area and the ignition tendencies. This extensive investigation will provide more insight in potential correlations between the maximum rate of pressure rise and the properties of nanomaterials such as chemical composition, surface area, diameter, porosity of nanomaterial aggregates, etc. The results will serve as the basis for the development of the fundamental theory of nano dust explosion. This justifies the INTELLECTUAL MERIT of this project. Because of the limited information available about this area and the uncertainty in the behavior of nanomaterials, the proposed research can be considered as a "high-risk" project. However, the research outcomes from this work have the potential for providing valuable qualitative and quantitative information that will contribute to address the safety issues encountered by industry regarding estimation of the explosion risks associated with engineered nanomaterials ("high-payoff"). Therefore, this research fits better the requirements for a NSF EAGER program instead a standard NSF program, which is intended for more established areas of research. The research proposed will employ existing equipments at our laboratories at Texas A&M University to study the dust explosion for combustible engineered nanomaterials. The results from the proposed research will set the foundations so that extensive long-term research projects could be realized to achieve complete understanding of related phenomena such as combustion mechanism and explosion properties. Further, this research will help to establish robust and consistent test methodologies in order to quantify the fire and explosion risks associated with engineered nanomaterials. This project will be valuable in determining the areas where a gap in knowledge exists and where future research should be focused.