Benchtop ultra-small angle X-ray scattering system for nanoscale and nanoparticle characterization

我们建议购买一台NANOPIX小型实验室规模的超小角X射线散射(USAXS)系统，以测试纳米颗粒的尺寸、孔隙率和聚集行为。Marangoni小组实施了USAXS技术来研究食用脂肪的纳米晶体结构。对脂肪进行15分钟的分析将产生从4纳米到10微米的长度尺度的结构信息。开发的技术和理论都为这些材料的结构及其与功能的关系提供了宝贵的见解。这项研究得出的最重要的参数之一是结晶纳米小板(CNP)的大小。CNP的长度可以在100 nm到400 nm之间，宽度可以在60 nm到100 nm之间，厚度可以在20 nm到40 nm之间。CNP对成分、冷却速度和剪切的变化极为敏感。例如，我们报告了巧克力的回火过程导致CNP尺寸减少了10倍。因此，我们开发了一种针对这些食品材料中纳米级的结构探测器。这些实验不得不在芝加哥阿贡国家实验室的同步辐射X射线设施中进行，因为圭尔夫大学没有所需的设备。获取设备的困难严重限制了可以进行的研究的类型和数量。NANOPIX机器将使我们能够对脂肪和油的加工、它们的组成和它们的纳米晶体结构之间的相关性进行更多的探索性研究。确定这种相关性对于用油凝胶和结构化乳剂取代硬脂，在不影响功能和质量的情况下改善营养特性至关重要。同样的方法将扩展到蛋白质凝胶。彭西尼实验室感兴趣的是开发具有可调孔隙率的颗粒，用于定向输送试剂以修复地下污染物。彭西尼实验室还对使用由天然乳化剂(如大豆卵磷脂，一种类似表面活性物质的脂肪)稳定的乳化凝胶来处理地表水域的化学泄漏感兴趣。乳化凝胶必须在净化地表水所需的时间内保持稳定。凝胶稳定性与油-水界面的乳化膜结构和稳定物种的聚集行为密切相关，如表面活性物质类脂肪(如卵磷脂)。周实验室感兴趣的是了解水中絮凝蛋白质、胞外物质和精细分散的有机物的大小和结构，以优化用于净水的高级滤膜的设计。污染絮体的大小是设计具有最佳膜孔径的膜所必需的。此外，污染絮体的孔隙率与絮体的强度有关。周实验室对使用添加剂来提高絮凝体强度很感兴趣，因为在水处理厂中，强大的絮凝体在受到剪切时不太容易解聚。*****

We propose to purchase a NANOPIX mini lab-scale Ultra-Small Angle X-ray Scattering (USAXS) system to examine the size, porosity and aggregation behavior of nano-particles. The USAXS technique was implemented for the study of the nanoscale crystalline structure of edible fats by the Marangoni group. A 15-minute analysis of a fat would yield structural information at length scales from 4 nm to 10 um. Both technique and theory developed yielded valuable insight into the structure of these materials and its relationship to functionality. One of the most important parameters derived from this study is the size of a crystalline nanoplatelet (CNP). CNPs can have lengths between 100 nm and 400nm, widths between 60 nm and 100nm and thicknesses between 20 nm and 40nm. CNPs are extremely sensitive to changes in composition, cooling rate and shear. For example, we reported that the tempering process in chocolate led to a 10-fold reduction in CNP size. We have thus developed a structural probe for the nanoscale in these food materials. These experiments had to be carried out at the synchrotron X-Ray facility at Argonne National Labs in Chicago because the required equipment is not available at the University of Guelph. The difficulty in accessing the equipment severely limits the types and number of studies that can be carried out. The NANOPIX machine will allow us to carry out more exploratory studies on the correlation between the processing of fats and oils, their composition and their nanoscale crystalline structure. Defining this correlation is crucial to replace hard fats with oleogels and structured emulsions to improve nutritional properties without affecting functionality and quality. The same approach will be extended to protein gels. The Pensini lab is interested in developing particles with tunable porosity for the targeted delivery of reagents to remediate subsurface contaminants. The Pensini lab is also interested in treating chemical spills on surface waters using emulsion gels stabilized by natural emulsifiers (e.g. soy lecithin, a surfactant-like fat). Emulsion gels must be stable during the time required to decontaminate surface waters. Gel stability is strongly correlated to the structure of the emulsifier films at the oil-water interface and to the aggregation behaviour of the stabilizing species such as surfactant-like fats (e.g. lecithin). The Zhou lab is interested in understanding the size and structure of flocculated proteins, extracellular material and finely dispersed organic matter in water, to optimize the design of advanced filtration membranes for water purification. The size of the contaminant flocs is required to design membranes with the optimal membrane pore size. Also, the porosity of contaminant flocs is correlated with the strength of the flocs. The Zhou lab is interested in using additives to improve floc strength, because strong flocs are less prone to disaggregating when subject to shear in water treatment plants. *****