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

美国蒙大拿州立大学（MSU）图像与化学分析中心（ICAL）为获得一台扫描力显微镜（SFM）和一台低温处理系统提供了奖励，后者是现有扫描电子显微镜（SEM）的附件。这些仪器将补充现有的成像和分析设备，用于描述固态材料的形态、原子结构、组成和化学性质，并将扩大国际化学研究所进行类似研究的能力，包括对自然状态下的生物标本进行现场描述。ICAL是一个中心的、多学科的用户设施。它的成立是为了满足研究需求，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提供了急需的基于显微镜和光谱学的分析设备，用于材料的体积和表面分析。目前，该实验室拥有具有能量色散x射线微分析（EDS），阴极发光光谱仪（CL）和背散射电子（BSE）微分析能力的SEM；扫描俄歇探针（SAM）；小点x射线光电子能谱仪；具有离子显微功能的飞行时间二次离子质谱仪（ToF-SIMS）；以及一台自动X射线粉末衍射仪（XRD）。高分辨率SFM将增强和扩展这些能力的范围，以提供天然和合成固体材料以及生物样品表面的形貌和组成、粘附、摩擦和粘弹性变化的原位、纳米级表征。SFM可以在流体环境下工作，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。在液体或空气中以触点或接触方式操作的高分辨率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，这超出了传统电子显微镜的范围。扫描电镜的冷冻制备阶段将允许在其自然状态下对生物样品进行高分辨率成像，而没有引入与标准样品制备程序相关的人工制品的风险。由于冷冻固定的关键优势，使标本能够保存在最接近其自然生存状态的状态，再加上电子显微镜的成像和光谱兼容性，研究保存在水合环境中的生物体成为可能。在研究合成和天然物质中微量元素的分布时，低温态也会增强CL信号。ICAL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，也为私营部门和政府机构的研究提供支持。现有的设备项目支持许多但不是所有的研究需要，许多团体。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研究表面上的生物膜形成，目前可以获得感兴趣区域的化学图谱，但无法获得自然环境中细菌的简单高分辨率图像，因为现有设备不具备进行此类研究的能力。拟议的设备将以一种非常重要的方式增加这些研究人员可用的仪器。提出了其他项目来表征自然系统中有机和重金属污染物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领域的生命科学家以及物理、化学、地球科学、植物和土壤科学领域的材料科学家提出。

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.