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博里叶变换红外(FT-IR)光谱具有光通量、速度和频率精度都超过传统色散型的红外光谱的优点。因此FT-IR是理想的适用于微量样品研究的仪器。本文中,我们将介绍一种用于FT-IR光谱仪的非常灵敏的微量取样附件的设计及它的一些应用。在别的地方叙述过的微量取样附件是由全反红外显微镜组成,安装在仪器的样品室之上。由FT-IR仪器出来的红外光束聚焦到样品上,样品是水平地固定在一个标准的显微镜的X-Y平台上。由样品透射或反射的辐射用一个卡塞格仑物镜来会聚。该物镜在显微镜主体内产生样品的一个象,在该象平面上有一个可变光阑用来分离出样品的感兴趣的部位。通过该光阑的光聚焦在一个非常灵敏的小面积的MCT探测器上。直线排列的可观察的成象系统允许对样品进行直观的观察。该微量取样附件可以记录尺寸大小从20μm×20μm到250μm×250μm的样品的FT-IR光谱。本文将介绍微型FT-IR技术的各种应用。这些应用包括显微微粒的辨别,例如液体里不希望的悬浮物,煤粒不均匀性的研究等等。在高聚物分析方面,该技术可用来研究缺陷,例如高聚物薄膜中的凝胶和雾点。高聚物层压材料可穿过其厚度做成切片,以记录每一层的光谱。
Fourier Transform Infrared (FT-IR) spectroscopy has the advantage of having a luminous flux, speed, and frequency accuracy over conventional dispersive infrared spectroscopy. Therefore FT-IR is ideal for trace sample research instruments. In this article, we describe the design of a very sensitive micro-sampling accessory for FT-IR spectroscopy and some of its applications. Trace sampling accessories described elsewhere are composed of an all-IR microscope mounted on the sample chamber of the instrument. The infrared beam from the FT-IR instrument is focused on a sample that is horizontally mounted on a standard microscope X-Y platform. Radiation transmitted or reflected by the sample is focused by a Cassegrain objective. The objective produces an image of the sample within the body of the microscope with an iris on the image plane for separating the region of interest of the sample. The light passing through this aperture focuses on a very sensitive small area MCT detector. An inline array of observable imaging systems allows for visual observation of the sample. The trace sampling accessory can record FT-IR spectra of samples ranging in size from 20 μm × 20 μm to 250 μm × 250 μm. This article describes the various applications of the miniature FT-IR technology. These applications include the identification of microparticles, such as unwanted suspensions in liquids, the study of coal particle inhomogeneities, and the like. In polymer analysis, this technique can be used to investigate defects such as gels and fog spots in polymer films. The polymer laminate can be sliced through its thickness to record the spectrum of each layer.