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

CBET-1321581纳米材料生产和使用的快速增长克服了研究与这些材料相关的危险的速度。虽然这方面的大部分研究都致力于了解工作场所暴露所造成的纳米材料毒理学，但很少有人关注与可燃工程纳米材料相关的火灾和爆炸危险。因此，迫切需要能够量化与可燃工程纳米材料相关的火灾和爆炸风险的技术标准。已有的微细粉尘材料粉尘爆炸危害研究的结论是，当粉尘颗粒尺寸减小到一定程度时，受限粉尘爆炸的严重程度会增加，在此之后，颗粒尺寸对粉尘爆炸的影响不大。因此，存在许多不确定因素，无法对微米和纳米颗粒在粉尘爆炸现象中的行为做出概括性的解释。因此，透彻的理解将带来更广泛的影响，导致发展全面的实验和理论信息，以支持纳米材料的使用和生产(有意/无意)的法规和风险分析。在这项研究中，将调查商业上可获得的金属和非金属可燃工程纳米材料及其微尺度对应材料。这些纳米材料的最小爆炸浓度(MEC)、最大压力(Pmax)、最大压力上升速率([dp/dt]max)和最低点火温度(MIT)等常规爆炸特性将在实验上进行评估，这些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，而且团聚程度对爆炸行为有很大的影响，因此全面了解纳米材料的分散和团聚行为，确定相应的颗粒直径和比表面积与点火倾向之间的关系是至关重要的。这项广泛的研究将提供更多关于最大压力上升速率与纳米材料的化学成分、比表面积、直径、孔隙率等纳米材料性质之间的潜在相关性的见解，这些结果将为发展纳米粉尘爆炸的基本理论提供基础。这证明了这一项目的学术价值。由于这一领域可获得的信息有限，以及纳米材料行为的不确定性，拟议中的研究可以被认为是一个“高风险”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，这些信息将有助于解决工业界在估计与工程纳米材料相关的爆炸风险(“高回报”)方面遇到的安全问题。因此，这项研究更符合NSF EIGER计划的要求，而不是标准的NSF计划，后者旨在更成熟的研究领域。这项拟议的研究将利用我们在德克萨斯农工大学的实验室现有的设备来研究可燃工程纳米材料的粉尘爆炸。拟议研究的结果将为实现广泛的长期研究项目奠定基础，以实现对燃烧机制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，以便量化与工程纳米材料相关的火灾和爆炸风险。该项目将有助于确定哪些领域存在知识差距，哪些领域应作为未来研究的重点。

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.