Entrainment and Detection of Engineered Nanoparticles

拟议的研究通过两种方式解决了了解工程纳米颗粒在工作场所暴露的需求：(i)研究工程纳米颗粒可能通过空气传播的基本机制；（ii）开发气溶胶仪器，适用于日常工作场所和个人监测1-500纳米尺寸范围内的纳米颗粒，并能够跟踪设计良好的纳米颗粒合成系统中可能导致大多数暴露的瞬态。受控的实验室实验也将进行，以发展对纳米颗粒释放到空气中的机制的基本理解，从纳米颗粒涂层表面的空气动力学夹带研究开始。长期以来对监测工作场所暴露的合适仪器的需求将通过创建一个小型，简单，低成本的纳米颗粒反迁移气溶胶检测器（NOMAD）来解决，该检测器将使暴露评估具有足够的分辨率来估计肺部沉积模式。NOMAD的性能将与纳米技术实验室中传统的暴露监测方法进行比较，并提供目前不可能的个人暴露数据。智力优势：拟议的研究将使用具有更好的时间响应和更广泛的潜在尺寸范围的尺寸分辨仪器来调查空气中纳米颗粒的来源，从而能够检测瞬时释放事件，并促进纳米颗粒来源的识别。随后的受控实验室实验将量化从不同种类的表面沉积物中夹带纳米颗粒所需的力，以及由此产生的空气中纳米颗粒的团聚程度，从而为潜在暴露机制的基本理解奠定基础。这些新仪器将使健康影响研究成为可能，这些研究显然需要了解纳米技术的风险，但由于现有仪器的成本和复杂性，目前还不可能。有了这些工具，连续暴露数据将成为健康影响研究和工人保护的宝贵工具。它们将进一步使人们能够研究在使用消费纳米技术产品和从传统污染源接触纳米粒子的情况。更广泛的影响：拟议的研究将为导致工程纳米颗粒释放到工作场所空气中的偶然过程以及与这种释放相关的风险提供新的见解。新的机载纳米粒子探测器将使研究人员和工业界能够严格监测纳米粒子暴露，这是现在不可能做到的。此外，这些新的检测器应该成为健康影响研究的使能技术，这显然是需要的，但目前还不可能。本科生将有机会通过加州理工学院参与该项目。本科生暑期研究奖学金（SURF）。此外，Flagan实验室将从少数民族本科生研究奖学金（MURF）项目中招募参与者，就像过去6年中有4年一样。我们会和加州理工学院合作吗？S外展计划，邀请当地学生到我们的实验室讲课和参观，并与他们学校的学生交谈。来自当地高中的学生，特别是那些靠近高速公路的学生，将被招募参加科学项目，包括在他们的家庭或学校环境中测量纳米粒子。正如他10年来所做的那样，PI将继续在RamonaConvent中学（一所位于加州阿尔罕布拉的女子高中，少数族裔入学率为60%）共同指导First Robotics团队。事实证明，通过向学生展示工程是有趣的，这是激发学生在大学里学习STEM的兴趣的最有效的机制。

CBET-1236909The proposed research addresses the need to understand workplace exposures to engineered nanoparticlesin two ways: (i) by investigating fundamental mechanisms by which engineered nanoparticlesmay become airborne; and (ii) by developing aerosol instruments suitable for routine workplace andpersonal monitoring of nanoparticles in the 1-500 nm size range with the ability to follow transientthat may be responsible for most exposure from well-designed nanoparticle synthesis systems.Controlled laboratory experiments will also be conducted to develop a fundamental understandingof mechanisms for nanoparticle release to the air, beginning with studies of the aerodynamicentrainment from nanoparticle-coated surfaces. The long-standing need for suitable instrumentsfor monitoring workplace exposures will be addressed by creating a small, simple, and low costnanoparticle opposed migration aerosol detector (NOMAD) that will enable exposure assessmentwith sufficient resolution to estimate lung deposition patterns. The NOMAD performance will becompared with conventional approaches to exposure monitoring in nanotechnology laboratories, andprovide personal exposure data that is not presently possible.Intellectual merit: The proposed research will survey sources of airborne nanoparticles usingsize resolved instruments with better time response, and broader coverage of the potential sizerange than employed in previous studies, thereby enabling detection of transient release events, andfacilitating identification of nanoparticle sources. Subsequent controlled laboratory experiments willquantify the forces required to entrain nanoparticles from different kinds of surface deposits, and theextent of agglomeration the airborne nanoparticles that result, thereby laying the groundwork fora fundamental understanding of potential exposure mechanisms. The new instruments will enablehealth effects studies that are clearly needed to understand the risks of nanotechnology, but arenot presently possible due to the cost and complexity of present instruments. With these tools,continuous exposure data will become a valuable tool in both health effect research and in workerprotection. They will further enable studies of exposures to nanoparticles in the use of consumernanotechnology products, and from conventional pollution sources.Broader impacts: The proposed research will provide new insights into incidental processesthat contribute to the release of engineered nanoparticles into workplace air, and the risks associatedwith such releases. The new airborne nanoparticle detectors will enable researchers and industry tomonitor nanoparticle exposures with rigor that is not now possible. Moreover, these new detectorsshould become the enabling technology for health effects studies that are clearly needed, but notpresently possible.Undergraduates will have the opportunity to become involved in the project through Caltech?sSummer Undergraduate Research Fellowship (SURF). In addition, the Flagan laboratory will recruitparticipants from the Minority Undergraduate Research Fellowship (MURF) program as it has in4 of the last 6 years. We will work with Caltech?s outreach program to invite local area students tolectures and visits to our laboratory, as well as talk to the students in their schools. Students fromlocal high schools, particularly those near freeways, will be recruited to undertake science projectsinvolving measurements of nanoparticles in their home or school environments.As he has done for 10 years, the PI will continue to co-mentor a First Robotics team at RamonaConvent Secondary School, a girls high school in Alhambra, CA that has 60% minority enrollment.This has proven to be a most effective mechanism in stimulating interest in pursuing STEM studiesin college by showing the students that engineering is fun.