Acquisition of a Scanning Force Microscope and a Cryo-preparation System for a SEM

9704089蒙大拿州立大学(蒙大拿州立大学)图像与化学分析研究所为购置一台扫描力显微镜和一套冷冻修复系统颁发了一份合同，后者是现有扫描电子显微镜的附件。这些仪器将补充现有的成像和分析设备，用于表征固态材料的形态、原子结构、组成和化学，还将扩大ICIC进行类似研究的能力，涉及对处于自然状态的生物标本进行现场表征。ICAL是一个中央、多学科和跨学科的用户设施。它的建立是为了满足研究需要，并促进在物理和生命科学以及工程学科的研究、教育和工业技术应用方面的合作。ICAL以显微镜和光谱分析为基础，为材料的整体和表面分析提供急需的分析设施。目前，该实验室拥有具有能量色散X射线显微分析(EDS)、阴极发光光谱仪(CL)和背散射电子(BSE)显微分析能力的扫描电子显微镜(SEM)；扫描俄歇微探针(SAM)；小斑X射线光电子能谱仪(XPS)；具有离子显微镜能力的飞行时间二次离子质谱仪(ToF-SIMS)；以及自动化X射线粉末衍射仪(XRD)。高分辨率的SFM将增强和扩展这些能力的范围，以提供对天然和合成固体材料以及生物样品表面的形态和组成、粘合、摩擦和粘弹性变化的原位纳米级表征。SFM可以在流体环境下运行，因此可以用于监测经历了吸附、催化和溶解/沉淀过程的材料。在液体或空气中轻击或接触操作模式的高分辨率SFM使复杂的生物结构以及复杂的大分子可以在其自然环境中进行研究，这一能力超出了传统电子显微镜的范围。扫描电子显微镜的冷冻准备阶段将允许对自然状态下的生物样品进行高分辨率成像，而不会有引入与标准样品制备程序相关的人工制品的风险。冷冻固定的关键优势使标本可以保存在最接近其自然生存状态的状态下，再加上电子显微镜的成像和光谱兼容性，对保存在水合环境中的活生物的研究成为可能。在研究合成和天然材料中的微量元素分布时，低温状态也将增强化学发光信号。ICIC设施为密歇根州立大学所有科学和工程领域的研究人员提供服务，也支持私营部门和政府机构的研究。现有的设备支持许多但不是许多团体的所有研究需要。例如，来自美国国家科学基金会支持的生物膜工程中心的研究人员在表面上研究生物膜的形成，目前可以获得感兴趣区域的化学图谱，但无法获得细菌在其自然环境中的简单高分辨率图像，因为现有的设备没有进行此类研究的设备。拟议的设备将以一种非常重要的方式增强这些研究人员可用的仪器。还提出了其他项目，以确定有机污染物和重金属污染物在自然系统中的分布和地球化学途径。相关项目由微生物学和植物病理学的生命科学家以及物理、化学、地球科学和植物土壤科学的材料科学家提出。

9704089 Avci An award is provided for the acquisition of a Scanning Force Microscope (SFM) and a Cryopreparation System, the latter as an accessory for an existing scanning electron microscope (SEM), in the Image and Chemical Analysis (ICAL) of Montana State University (MSU). These instruments will complement existing imaging and analytical equipment used to characterize the morphology, atomic structure, composition and chemistry of solid state materials, and will also expand the capability of ICAL to undertake similar studies involving in situ characterization of biological specimens in their natural state. ICAL is a central, multi- and interdisciplinary user facility. It was established in order to serve research-needs and promote collaboration in research, education, and industrial technical applications in the physical and life sciences, as well as engineering disciplines. ICAL provides critically needed analytical facilities based on microscopy and spectroscopy for bulk and surface analysis of materials. At present, the laboratory is home to an SEM with energy dispersive X-ray microanalysis (EDS), cathodoluminescence spectrometer (CL), and backscattered-electron (BSE) microanalysis capabilities; a scanning Auger microprobe (SAM); a small-spot X-ray photoelectron spectrometer (XPS); a time of flight secondary ion mass spectrometer (ToF-SIMS) with the ability to do ion microscopy; and an automated X- ray powder diffractomer (XRD). A high resolution SFM will augment and extend the range of these capabilities to provide in situ, nanometer-scale characterization of the morphology and variations in composition, adhesion, friction, and viscoelasticity on the surfaces of natural and synthetic solid materials as well as biological samples. The SFM can operate under fluid environments, and thus, can be used to monitor materials that have undergone sorption, catalytic, and dissolution/precipitation processes. A high-resolution SFM in tapping or contac t mode of operation in liquid or air makes complex biological structures as well as complex macromolecules accessible to study in their natural environment, a capability outqide the scope of traditional electron microscopy. The cryo-preparation stage for the SEM will allow high- resolution imaging of biological samples in their natural state, without the risk of introducing artifacts associated with standard sample preparation procedures. With the crucial advantage of cryo- fixation allowing the specimen to be preserved in a state closest to its natural living state, added to the imaging and spectroscopic compatibility of the electron microscope, study of living organisms preserved in their hydrated environments become possible. The cryo- state will also enhance the CL signal in studies of trace element distribution in synthetic and natural materials. The ICAL facility serves researchers in all fields of science and engineering at MSU and also supports research in the private sector and government agencies. The existing items of equipment support many but not all the research needs of many groups. For example, the researchers from the NSF-supported Center for Biofilm Engineering who study biofilm formation on surfaces can currently obtain chemical mapping over the region of interest, but are unable to obtain simple high resolution images of bacteria in their natural surrounding, since the existing equipment is not equipped to carry out such research. The proposed equipment will augment in a very essential way the instrumentation available to these researchers. Other projects are proposed to characterize the distribution and geochemical pathways of organic and heavy metal contaminants in natural systems. Related projects are proposed by life scientists in Microbiology and Plant Pathology as well as materials scientists in Physics, Chemistry, Earth Sciences, and Plant and Soil Sciences.