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

摘要：阿肯色大学小石城分校（UALR）与阿肯色州立大学、阿肯色儿童医院和阿肯色大学医学科学学院合作，计划开发一种仪器，用于研究空气中微小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，即使借助标准的实验室显微镜也看不见，可能对肺部和心脏造成严重损害（《科学杂志》，2005年3月25日），这些有害的健康影响涉及许多行业——从煤烟和汽车尾气中的颗粒到宇航员在执行登月和火星任务时将接触到的月球或火星尘埃。因此，在纳米技术的新兴发展中，工业在控制纳米粒子带来的危害方面面临着许多挑战，也许更重要的是，纳米技术可以在工程和医疗技术方面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和顺序组装在一起，形成新的工程材料和医疗药物，这些材料和药物是目前任何机械工具都无法组装的。例如，这为囊性纤维化患者的新药开发和输送技术开辟了道路。专家预测，在未来20年里，解决当前新兴纳米技术的两个方面的经济发展将仅在美国就发展成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。在拟议的为期两年的仪器发展应用计划下，它将用于研究：1)用于医疗器械的材料涂层开发，以及用于呼吸输送的新药开发，2)研究来自各行业的纳米颗粒对环境的不利影响，3)为美国太空和导弹防御司令部检测空气中的化学物质和生物毒素，以及针对纳米颗粒吸入的新型呼吸保护的开发。4)改进先进的工程工艺，减少汽车工业中纳米颗粒废气污染物的排放。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，因为大学教师将与学校教师合作，为学生在大学水平的教育和研究做好准备。技术摘要：阿肯色大学小石城分校（UALR）的一组研究人员提出了一种基于激光的仪器，可以实时测量直径为10至1000 nm的颗粒的粒径和静电电荷分布。该仪器将采用激光多普勒测速仪（LDV），该测速仪将分析在交流电场和声场同步激励下粒子运动的响应，频率范围为10至100千赫。直径（da）和电荷(q)的每一个粒子通过LDV传感体积，是通过测量相位滞后和振幅比的振荡粒子运动相对于应用正弦场确定的。利用高频光子相关器和冷却光电倍增管处理粒子散射的辐射信号，以每秒1000个粒子的速率测量粒子的大小和电荷分布。这种新型的电声单粒子空气动力学弛豫时间（ESPART）分析仪将用于纳米颗粒的研究项目，该项目由UALR的科学家、工程师和医生团队以及美国和国外的其他校园进行，包括阿肯色儿童医院和阿肯色大学医学科学。这些项目包括：1)纳米颗粒的空气动力学和电动运输、沉积和团簇形成的材料工程研究，不同尺寸和成分的空气悬浮颗粒的电动力学引导组装，开发用于呼吸输送的新药物，以及用于心血管支架涂层的纳米颗粒的电喷涂。2)利用物理模型研究吸入纳米颗粒的区域肺沉积与尺寸和电荷的关系。3)为美国太空和导弹防御司令部检测空气中的化学物质和生物毒素，开发新的呼吸防护装置，防止纳米颗粒吸入，4)等离子体工艺在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从九年级到完成材料工程博士课程的学生的综合教育，因为大学教师将与学校教师和学生合作，为学生在大学水平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.