IMR: Developement of an Analyzer for Size and Charge Characterization of Nanoparticles in Research and Training

非技术摘要：位于小石城的阿肯色州大学（UALR）与阿肯色州州立大学、阿肯色州儿童医院和阿肯色州大学医学科学院合作，正在提议开发一种仪器来研究微小尺寸的空气颗粒的特性及其在环境健康、科学、医学和经济发展中的作用。这些颗粒太小，即使在标准实验室显微镜的帮助下也无法看到，可能会对肺部和心脏造成严重损害（Science杂志，2005年3月25日），这些不利的健康影响涉及许多行业-从煤烟和汽车尾气中存在的颗粒到宇航员在月球和火星任务中将接触到的月球或火星尘埃。在纳米技术的新兴发展中，工业界因此在控制纳米颗粒所带来的危害方面面临许多挑战，也许更重要的是纳米技术可以为工程和医疗技术提供无数有益的应用。这些纳米颗粒可以通过非接触力以精确的结构组装在一起，从而形成新的工程材料和医疗药物，这些材料和药物不适用于现有的任何机械工具的组装。例如，这为囊性纤维化患者开辟了新药开发和输送技术的途径。专家预测，在未来20年内，仅在美国，解决目前新兴纳米技术的两个方面的经济发展将发展成为一个万亿美元的产业。UALR将开发一种新的仪器来测量粒子的大小和静电荷分布，并控制它们在电场，磁场和引力场中的运动。在拟议的两年期仪器开发应用项目下，它将用于研究：1）医疗设备的材料涂层开发，以及呼吸输送的新药开发，2）研究来自各个行业的纳米颗粒的不良环境影响，3）为美国太空和导弹防御司令部检测空气中的化学品和生物毒素，以及针对纳米颗粒吸入的新的呼吸保护的开发，以及4）在减少汽车工业中纳米颗粒废气污染物的排放方面的先进工程工艺的改进。 拟议的研究旨在支持从9年级到完成博士课程的学生的综合教育，因为大学教职员工将与学校教师合作，为学生在大学一级的教育和研究做好准备。技术摘要：基于激光的真实的时间和单颗粒同时测量颗粒尺寸和静电荷分布的仪器的开发位于小石城的阿肯色州大学（UALR）的一组研究人员提出了一种用于直径在10至1000 nm尺寸范围内的颗粒的方法。该仪器将采用激光多普勒测速仪（LDV），该仪器将分析在频率范围为10至100 KHz的交流电场和声场的激励下粒子运动的响应。通过测量振荡粒子运动相对于所施加的正弦场的相位滞后和振幅比来确定穿过LDV感测体积的每个粒子的直径（da）和电荷（q）。高频光子相关器和冷却光电倍增管将用于处理粒子散射辐射的信号，以每秒1000个粒子的速度测量粒子的大小和电荷分布。这种新的电声单粒子空气动力学弛豫时间（ESPART）分析仪的应用纳米粒子将被用于几个研究项目正在执行的科学家，工程师和医生的团队在UALR，和其他校园在美国和国外，包括阿肯色州儿童医院和阿肯色州大学医学科学。这些项目包括：1）纳米颗粒的空气动力学和电动力学运输的材料工程研究，它们的沉积和簇形成，开发用于呼吸递送的新药的不同尺寸和组成的气载颗粒的电动导向组装，以及用于涂覆心血管支架的纳米颗粒的电喷雾2）使用物理模型研究吸入的纳米颗粒的局部肺沉积作为尺寸和电荷的函数，3）为美国太空和导弹防御司令部检测空气中的化学品和生物毒素，以及开发新的呼吸保护以防止纳米颗粒吸入，以及4）等离子体工艺以减少汽车工业中纳米颗粒废气污染物的排放。 拟议的研究和教育项目旨在支持学生的综合教育，从9年级到完成材料工程博士课程，因为大学教师将与学校教师和学生合作，为学生在大学一级的教育和研究做好准备。

Non-Technical Abstract: The University of Arkansas at Little Rock (UALR), in collaboration with Arkansas State University, Arkansas Children's Hospital, and the University of Arkansas for Medical Sciences, is proposing to develop an instrument to study the properties of minute-sized airborne particles and their roles in environmental health, science, medicine, and economic development. These particles, too small to be visible even with the aid of a standard laboratory microscope, may cause serious damage to both the lungs and the heart (Science Magazine, 25 March 2005), and these adverse health effects range across many industries - from particles present in soot and automotive exhaust to lunar or Martian dust that astronauts will be exposed to in human missions to the Moon and Mars. In the emerging development of nanotechnology, industries thus face many challenges in controlling the hazards presented by nanoparticles, and perhaps even more importantly are the myriad beneficial applications to engineering and medical technologies that nanotechnology can provide. These nanoparticles may be assembled together by non-contact forces in a precise structure and order to form new engineering materials and medical drugs not feasible for assembly with any current mechanical tools in existence. This, for instance, opens the pathway to new drug development and delivery techniques for cystic fibrosis patients. Experts predict that economic development to address the two sides of currently emerging nanotechnology will grow into a trillion dollar industry in the United States alone over the next two decades. UALR will develop a new instrument to measure the size and static charge distribution of the particles and to control their motion in electric, magnetic, and gravitational fields. Under the proposed two-year instrument development application project, it will be used to study: 1) Material coatings development for medical devices, and new drug development for respiratory delivery, 2) studies on the adverse environmental effects of nanoparticles from various industries, 3) detection of chemicals and biotoxins in the air for US Space and Missile Defense Command, and the development of new respiratory protection against nanoparticle inhalation, and 4) the improvement of advanced engineering processes in reducing the emission of nanoparticle exhaust pollutants in the automotive industry. The proposed research is designed to support integrative education of students from grade 9 up to the completion of a PhD program, as the university faculty members will work with school teachers preparing the students for education and research at the university level.Technical Abstract: Development of a laser based instrument to measure simultaneously both particle size and electrostatic charge distributions in real time and on a single particle basis for particles in the size range 10 to 1000 nm in diameter is proposed by a team of researchers of the University of Arkansas at Little Rock (UALR). The instrument will employ a Laser Doppler Velocimeter (LDV) that will analyze the response of particle motion under the excitation of ac electric and acoustic fields synchronously applied at a frequency ranging from 10 to 100 KHz. The diameter (da) and the charge (q) of each particles passing through the LDV sensing volume, are determined by measuring the phase lag and the amplitude ratio of the oscillatory particle motion with respect to the applied sinusoidal fields. A high frequency photon correlator and a cooled photomultiplier tube will be used to process signals from the radiation scattered from particles to measure the size and charge distributions at a rate of 1000 particles per second. Application of this new Electro-acoustic Single Particle Aerodynamic Relaxation Time (ESPART) Analyzer for nanoparticles will be utilized in several research projects being performed by the team of scientists, engineers, and physicians at UALR, and other campuses in the US and abroad including Arkansas Children Hospital and the University of Arkansas for Medical Sciences. These projects include: 1) Material engineering studies of aerodynamic and electrokinetic transport of nanoparticles, their deposition and cluster formation, electrodynamic guided assembly of airborne particles of different sizes and compositions developing new drugs for respiratory delivery, and electrospray of nanoparticles for coating cardiovascular stents 2) studies on the regional lung deposition of inhaled nanoparticles as a function of size and charge using physical models, 3) detection of chemicals and biotoxins in air for US Space and Missile Defense Command, and the development of new respiratory protection against nanoparticle inhalation, and 4) plasma processes in reducing the emission of nanoparticle exhaust pollutants in the automotive industry. The proposed research and education project is designed to support integrative education of students anywhere from grade 9 to the completion of a PhD program in material engineering, as the university faculty members will work with school teachers and students in preparing the students for education and research at the university level.