MRI: Acquisition of an AFM System for Imaging and Characterization of Synthetic Nanostructures and Native Biological Macromolecules

0922400ParkWilliams College“该奖项由2009年美国复苏和再投资法案(公法第111-5条)资助。”技术概述：原子力显微镜？S能够成像和表征表面形貌，通过相位或力成像识别样品的纳米级区域，甚至改变表面，使其成为具有纳米和微米级特征的系统研究中不可或缺的工具。威廉姆斯大学的几个研究项目(化学、物理、生物、计算机科学)都需要这些能力。Park小组专注于聚合物材料的设计，这种材料将自组织(基于聚合物链中的碳氢化合物-氟碳相互作用，以及与化学图案化表面的相互作用)，以提供具有增强有机光伏器件性能的内部结构的薄膜；AFM将用于表征聚合物薄膜，它们将被浇铸在其表面上，并通过DPN对基板进行构图。利用AFM在高温下的成像能力，洛佩斯？小组研究了两嵌段共聚物膜中缺陷结构的演变。出自？电影？该小组聚集在现场，研究了作为温度函数的缺陷动力学和动力学，以更好地了解此类材料的自组装过程。Ting小组研究在全球碳循环中起重要作用的海洋微生物的光合作用和相关过程。AFM将被用来表征天然膜中光合作用装置的结构，并研究双层内这些蛋白质复合体的组织和化学计量比的变化如何影响光合作用。威廉姆斯大学的其他几名研究人员也将使用AFM，其中包括Goh小组，该小组研究基于生物聚合物的靶向药物输送载体的设计，具有更好的生物兼容性和药物释放的延展性。GoH将使用成像来表征不同材料在三嵌段共聚物结构中的位置，并进行力曲线测量，以帮助确定结构。班塔小组正在探索土壤细菌根癌农杆菌中毒力蛋白的功能；AFM将用于研究这些VIR蛋白与DNA的结合方式，从而研究这些蛋白在促进T-DNA向宿主植物细胞传递方面所起的作用。McGuire-S的工作将利用表面原子力显微镜的地形信息来改进计算机图形学中描述表面光散射的模型，并寻找表面散射模型，这将改善光线跟踪并减少计算量。威廉姆斯大学的原子力显微镜将被整合到现有的显微镜设施中，其中包括透射电子显微镜和扫描电子显微镜，是研究和教育计划不可或缺的组成部分。莱曼摘要：扫描探针技术，将尖锐的尖端带到非常接近样本的地方，通过在表面上拖动尖端来收集关于样本的信息，已经成为科学界不可或缺的工具。原子力显微镜(AFM)就是一个例子，它可以生成表面特征的图像，以及以极高的(~nm)分辨率生成表面材料属性变化的地图。威廉姆斯学院正在进行的许多研究项目都需要使用原子力显微镜。其中包括对合成聚合物中形成的图案的研究，这些图案可用于产生纳米级特征(比计算机芯片设计中通过传统光刻获得的特征更小)，或可用于基于聚合物的太阳能电池和聚合物基药物输送载体；对对具有生态重要性的生物的光合作用至关重要的天然生物膜中蛋白质的结构和组织的研究；对将DNA运送到细胞中的蛋白质的研究；以及表面研究和与光散射实验的比较，以改进计算机图形学中使用的技术。

0922400ParkWilliams College"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)."Technical Summary: AFM?s ability to image and characterize surface topography, identify nanoscale regions of samples via phase or force imaging, and even alter surfaces, has made it an indispensable tool in research on systems with nano- and micro-scale features. Several research programs at Williams (in chemistry, physics, biology, computer science) require these capabilities. The Park group focuses on the design of polymeric materials which will self- organize (based on hydrocarbon-fluorocarbon interactions within the polymer chain, as well as interactions with chemically patterned surfaces) to give films with internal architectures for enhanced performance in organic photovoltaic devices; AFM will be used to characterize the polymer films, the surfaces on which they will be cast, and to pattern substrates via DPN. Using the imaging capabilities of AFM at elevated temperatures, Lopes? group studies the evolution of defect structure in diblock copolymer films. From ?movies? gathered in situ, the group studies the defect dynamics and kinetics as a function of temperature to better understand the self-assembly processes in such materials. The Ting group studies photosynthesis and related processes in marine microorganisms that have a major role in global carbon cycles. AFM will be used to characterize the architecture of the photosynthetic apparatus in native membranes and to study how alterations in the organization and stoichiometry of these protein complexes within a bilayer will affect photosynthesis. AFM will also be used by several other researchers at Williams, including the Goh group, which studies the design of biopolymer-based targeted drug delivery vehicles with improved biocompatibility and tenability of drug release. Goh will use imaging to characterize the location of differing materials within triblock copolymer structures and force curve measurements to aid in structure determination. The Banta group is exploring the function of virulence proteins in the soil bacterium A. tumefaciens; AFM will be used to study the mode of binding of these Vir proteins to DNA and, thus, the role these proteins play in promoting T-DNA delivery to host plant cells. McGuire?s work will use topographical information from AFM of surfaces to improve models for describing light scattering off of surfaces in computer graphics and to search for models of scattering from surfaces which will improve ray tracing and reduce their computational load. The AFM at Williams will be incorporated into an existing microscopy facility, which includes a TEM and SEM, and is an integral component of research and educational programs.Layman Summary: Scanning probe techniques, in which a sharp tip is brought extremely close to a sample and information about the sample is gathered by dragging the tip across a surface, have become indispensable tools for the scientific community. One example is Atomic Force Microscopy (AFM), which can generate images of features on surfaces as well as maps of variation in materials properties across surfaces with extremely high (~nm) resolution. Many on-going research projects at Williams College require the use of an AFM. These include studies of the patterns which form in synthetic polymers which can be used to generate nanoscale features (smaller than features attainable through conventional photolithography in computer chip design), or which could be used for polymer-based solar cells and polymer-based drug delivery vehicles; research on the structure and organization of proteins in native biological membranes critical for photosynthesis in ecologically important organisms; studies of proteins involved in delivery of DNA into cells; and research on surfaces and comparison with light scattering experiments to improve techniques used in computer graphics.