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

[参考译文]纳米材料的生产和使用的快速增长已经超过了与这些材料有关的危害的研究速度。虽然这方面的大多数研究都致力于了解工作场所暴露导致的纳米材料毒理学，但很少关注与可燃工程纳米材料相关的火灾和爆炸危险。因此，迫切需要一种技术标准来量化与可燃工程纳米材料相关的火灾和爆炸风险。已有的关于微粒径粉尘爆炸危害的研究表明，当粉尘粒径减小到一定程度后，密闭粉尘爆炸的严重程度会增加，超过一定程度后，粉尘粒径对粉尘爆炸的影响不显著。因此，由于存在许多不确定性，因此无法得出解释微纳米颗粒在粉尘爆炸现象中的行为的广义结论。因此，透彻的理解将带来更广泛的影响，从而为支持纳米材料的使用和生产（有意/无意）的法规和风险分析提供全面的实验和理论信息。在这项研究中，将研究商业上可用的金属和非金属可燃工程纳米材料，以及它们的微尺度对应物。这些纳米材料在最小爆炸浓度（MEC）、最大压力（Pmax）、最大压力增加率（[dP/dt]max）和最低点火温度（MIT）方面的常规爆炸特性，对于确定粉尘爆炸的可能性和严重性至关重要。此外，由于纳米材料具有团聚的倾向；由于团聚程度对爆炸行为有重要影响，因此全面了解纳米材料的分散和团聚行为，确定相应颗粒直径和表面积与着火倾向之间的关系至关重要。这项广泛的研究将为最大压力上升速率与纳米材料的性质（如化学成分、表面积、直径、纳米材料聚集体的孔隙度等）之间的潜在相关性提供更多的见解。研究结果将为纳米粉尘爆炸基础理论的发展提供依据。这证明了这个项目的智力价值。由于这一领域的信息有限，加之纳米材料行为的不确定性，这项研究被认为是一个“高风险”的项目。然而，这项工作的研究成果有可能提供有价值的定性和定量信息，有助于解决工业中遇到的与工程纳米材料（“高回报”）相关的爆炸风险评估的安全问题。因此，本研究更符合NSF EAGER项目的要求，而不是标准的NSF项目，后者是为更成熟的研究领域设计的。本研究计划将利用我们在德州农工大学的实验室现有设备，研究可燃工程纳米材料的粉尘爆炸。本研究的成果将奠定基础，以实现广泛的长期研究项目，以实现对燃烧机理和爆炸特性等相关现象的全面了解。此外，这项研究将有助于建立稳健和一致的测试方法，以量化与工程纳米材料相关的火灾和爆炸风险。这个项目对于确定存在知识差距的领域和未来研究的重点将是有价值的。

CBET - 1321581The 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.