FT—IR显微ATR红外光谱图像系统及其应用

ＦＴ－ＩＲ显微ＡＴＲ红外光谱图像系统是研究物体表面微区化学成分各成分在空间分布的分析测试系统。该系统将红外光谱与该光谱所在空间位置有机地联系起来,直接反映了某化合物或官能团在物体表面的分布状况。本文简要介绍了ＦＴ－ＩＲ显微ＡＴＲ红外光谱图象系统的表面微区测试原理和特点,以及在不同领域中的应用。     

焦平面阵列红外光谱图象系统——FT-IR光谱学的革命性进展

显微红外光谱学已成为现代FT-IR光谱学的一重要分支,利用红外显微镜进行的红外图象分析有两种方式:(1)传统的“画地图”—Mapping方式,利用自动显微镜载物台逐点移动样品,逐点测定其红外光谱;(2)最新的焦平面阵列(Focal Plane Array),红外图象系统,焦平面阵列式红外检测器含有128×128或64×64个阵列检测单元,它可以高空间分辨率快速完成较大面积的红外图象采集,该技术代表着FT-IR的最新发展,现已应用于生物学、医学、地质学、聚合物分析等领域。     

纳米级红外光谱用于聚合物的表征

尽管红外微光谱有广阔的用途,但是由于光学规则与实际设计的局限性,其基本的空间分辨率受到了限制.傅里叶变换红外光谱的空间分辨率局限于3倍的红外辐射波长.通过使用衰减全反射(ATR)的方式,可以将其空间分辨率接近于其辐射波长.纳米级红外光谱(Nano IR)技术可以解决分辨率的限制,提供一种在200 nm及其之上可以测量样品物理和化学性质的方法.     

基于μC/OS-Ⅱ的红外测温系统的设计

介绍了一种以ARM为处理器的红外测温系统,在系统中设计移植了实时操作系统μC/OS-Ⅱ,可以完成对圆盘表面温度的检测,并在LCD上显示物件表面各个区域的的温度及其分布曲线;通过触摸屏可以指定测量点。同时系统采用了开源的TCP/IP协议,可以实现系统与外部PC设备的连接和信息交互。该设计对红外探测物体表面的温度有一定的参考价值。     

PE—3600微机辅助红外光谱结构解析

利用PE红外分光光度计本身附带的3600型微计算机建立了红外光谱徽机辅助结构解析系统。该系统可以与红外分光光度计联机或脱机对未知物光谱进行结构分析,报告出未知样品若干种可能的结构基团的化学结构式及其相似性得分。     

空基红外系统作用距离建模及应用分析

针对现有红外系统作用距离模型影响因素考虑较少、难以准确评估系统探测能力及目标红外隐身效果的问题,开展空基红外系统作用距离建模及应用案例分析。分析典型红外系统作用距离的影响因素,定义大气光谱透过率与作用距离的隐函数,基于大气垂直高度层上温度差异明晰光谱辐射强度分布模型,考虑目标红外光谱辐射线型特征推导大气透过率加权修正系数,进而构建了综合目标光谱辐射特性、大气温度和红外系统高度等多种因素的空基红外系统对点目标作用距离模型。基于该模型,对不同类型空基红外系统的探测能力及不同类型目标的红外隐身性能进行了比较和分析。结果表明,对于导弹、飞机类目标,采用大口径、长波段系统设计有利于提升空基红外系统对目标迎头方向探测能力,大口径中波红外系统对目标尾后方向探测能力更强;小尺寸、低表面发射率、低速飞行目标的红外隐身及突防能力更好,目标在平流层飞行时隐身性能要优于对流层和中间层飞行目标。     

显微红外光谱技术及其在法庭科学中的应用

显微红外光谱技术包括高压金刚石池、红外显微镜与傅里叶变换红外光谱仪的联用技术,显微红外光谱技术可用于快速测定微量物质的高质量红外光谱。     

非制冷红外物镜设计中最佳波段的选择

根据常用大气窗口和常见物体辐射峰值波长,计算出黑体在233~313K范围内的光谱辐射出射度,结合红外探测器的光谱响应曲线得到非制冷红外镜头的设计波长及其权重。将该方法应用于实际物镜设计,发现光学系统波长及权重符合探测器焦平面输出信号光谱响应特性。该方法对非制冷红外热像光学系统的设计具有实际意义。     

DOI:10.3969/j.issn.0254-0150.2012.10.021

通过对润滑油红外光谱区间选择、平滑、求导等预处理和识别方法的选择,建立润滑油红外光谱专家识别系统,并介绍该系统的功能和使用方法.红外光谱预处理可以有效消除仪器等因素对光谱质量的影响;选择指纹区为润滑油的识别区间,避开了润滑油基础油的红外谱峰的影响,提高了识别准确度;普鲁克识别方法可以有效消除测样方式等对光谱质量的影响,进行润滑油指纹区的轨迹识别比通常的特征峰检索方法能更有效地识别润滑油红外谱图.利用所建的润滑油红外光谱专家识别系统对不同油品进行识别验证,结果表明所建的专家系统使用方便,能有效识别润滑油.     

Nicolet红外附件－OMNI采样器的应用

本文介绍了红外附件-OMNI采样器的应用，如对纤维与纺织品面料、易吸潮样品、复合材料、微量样品、颗粒状或形状不规则的固体样品，玻璃及其它硬质基体上的涂层等的直接测试，得到的红外谱图信噪比好、灵敏度高，经ATR校正后的谱图与红外标很谱图有很好的匹配度。传统的红外光谱分析方法对一些特殊样品，如不可破坏的、表层及不可处理和微量的样品很难直接测定，采用美国Nicolet单点衰减全反射OMNI采样器可以方便地解决上述问题。这种采样器用一个球形的极为坚固的锗晶体作为一个采样表面，通过压力塔对样品提供一个点对点的接触，压力塔上有压力保护装置，防止在操作时因压力过大而损坏晶体。压力塔上还有一个显微观察器可以使小样品方便精确定位。OMNI采样器测试范围4000—675cm^-1，穿透样品的深度在2000cm^1处大约0．67μm，适合pH范围l—14，是一个很好的通用的红外附件。     

Combined in situ (ATR FT-IR) and ex situ (XPS) Study of the ZnDTP-Iron Surface Interaction

Attenuated total reflection infrared (ATR FT-IR) and X-ray photoelectron spectroscopy (XPS) have been used for the in situ and ex situ characterization of thermal and tribological films formed on iron from a commercial zinc dialkyldithiophosphate (ZnDTP). From in situ ATR FT-IR analysis, information on the chemical changes occurring at the iron/lubricant additive interface was obtained during heating and sliding at high temperatures. Different mechanisms and chemical compositions have been found for the thermal and tribochemical reactions between the ZnDTP and the iron surface under the experimental conditions used in this work. Both the ATR FT-IR and the XPS results show the decomposition of ZnDTP with the formation of polyphosphates following thermal testing at 150°C. However, after tribological testing at the same temperature an inorganic phosphate film has been detected on the iron surface instead.     

Mechanisms of wear of steel by natural rubber in water medium

The wear mechanisms of steel by natural rubber (NR) in water medium were investigated. The surface profile, element constitutions and binding energies of the surfaces for both steel and rubber have been analyzed with scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS), respectively. Moreover, the functional groups of natural rubber surfaces were examined with Fourier transform infrared spectrometer (FT-IR). It has been found that the processes of wear of steel by NR involve two stages. Firstly, under the action of frictional forces, some mechanochemical reactions generated among the surfaces of steel and rubber as well as the water medium, which produced a chemical reaction film on the steel surface. Secondly, this film was destroyed and removed by the microcutting action of the debris on the sliding surface, as a result the steel surface wore off. The wear mechanisms might be mainly attributed to the chemistry–mechanics self-catalytic destruction mechanism of steel being rubbed by natural rubber.     

High throughput operando studies using Fourier transform infrared imaging and Raman spectroscopy

A prototype high throughput operando (HTO) reactor designed and built for catalyst screening and characterization combines Fourier transform infrared (FT-IR) imaging and Raman spectroscopy in operando conditions. Using a focal plane array detector (HgCdTe focal plane array, 128x128 pixels, and 1610 Hz frame rate) for the FT-IR imaging system, the catalyst activity and selectivity of all parallel reaction channels can be simultaneously followed. Each image data set possesses 16 384 IR spectra with a spectral range of 800-4000 cm(-1) and with an 8 cm(-1) resolution. Depending on the signal-to-noise ratio, 2-20 s are needed to generate a full image of all reaction channels for a data set. Results on reactant conversion and product selectivity are obtained from FT-IR spectral analysis. Six novel Raman probes, one for each reaction channel, were specially designed and house built at Pacific Northwest National Laboratory, to simultaneously collect Raman spectra of the catalysts and possible reaction intermediates on the catalyst surface under operando conditions. As a model system, methanol partial oxidation reaction on silica-supported molybdenum oxide (MoO3SiO2) catalysts has been studied under different reaction conditions to demonstrate the performance of the HTO reactor.     

Characterization of human ovarian teratoma hair by using AFM, FT-IR, and Raman spectroscopy

The structural, physical, and chemical properties of hair taken from an ovarian teratoma (teratoma hair) was first examined by atomic force microscopy (AFM), Fourier transform infrared (FT-IR), and Raman spectroscopy. The similarities and differences between the teratoma hair and scalp hair were also investigated. Teratoma hair showed a similar morphology and chemical composition to scalp hair. Teratoma hair was covered with a cuticle in the same manner as scalp hair and showed the same amide bonding modes as scalp hair according to FT-IR and Raman spectroscopy. On the other hand, teratoma hair showed different physical properties and cysteic acid bands from scalp hair: the surface was rougher and the adhesive force was lower than the scalp hair. The cystine oxides modes did not change with the position unlike scalp hair. These differences can be understood by environmental effects not by the intrinsic properties of the teratoma hair.     

Environmental effects in Kelvin force microscopy of modified diamond surfaces

We have explored the effects of atmospheric environment on Kelvin force microscopy (KFM) measurements of potential difference between different regions of test polycrystalline diamond surfaces. The diamond films were deposited by microwave plasma-assisted chemical vapor deposition, which naturally produces hydrogen terminations on the surface of the films formed. Selected regions were patterned by electron-beam lithography and chemical terminations of oxygen or fluorine were created by exposure to an oxygen or fluorine plasma source. For KFM imaging, the samples were mounted in a hood with a constant flow of helium gas. Successive images were taken over a 5-h period showing the effect of the environment on KFM imaging. We conclude that the helium flow removes water molecules adsorbed on the surface of the samples, resulting in differences in surface potential between adjacent regions. The degree of water removal is different for surfaces with different terminations. The results highlight the importance of taking into account the atmospheric environment when carrying out KFM analysis.     

In Situ Attenuated Total Reflection (ATR/FT-IR) Tribometry: A Powerful Tool for Investigating Tribochemistry at the Lubricant–Substrate Interface

To investigate the chemical changes occurring at metal/lubricant interfaces under tribological conditions in the boundary-lubrication regime, an in situ system for conducting quantitative tribological measurements has been constructed by combining an attenuated total reflection Fourier-transform infrared (ATR/FT-IR) spectrometer with a reciprocating tribometer. By periodically acquiring ATR/FT-IR spectra during sliding, spectroscopic changes due to thermal and/or tribochemical reactions occurring at the metal/oil interface can be monitored and correlated with friction measurements. The usefulness of this tribological test system has been demonstrated by performing ATR tribological experiments in the presence of a poly-α-olefin base oil at high temperature (423 K) on iron-coated germanium ATR crystals.     

Mid infrared microspectroscopic mapping and imaging: a bio-analytical tool for spatially and chemically resolved tissue characterization and evaluation of drug permeation within tissues

The combination of the two classical biophysical methods, microscopy and infrared spectroscopy, has led to the development of a potent analytical technology termed infrared microspectroscopy. It combines high lateral resolution as obtained by microscopy and the chemical identification of the sample components by infrared spectroscopy. The two approaches mainly utilized in microspectroscopy are the mapping and the imaging techniques, which are introduced and presented. Especially, since the development of so called focal plane array detectors, which are implemented in the imaging methods (microspectroscopic imaging) has become a promising bio-analytical tool for ultrastructural medical diagnostics, due to the fact that the time required for analyzing a sample has been reduced dramatically and the lateral resolution improved to approximately 4 microm. Mid infrared microscopy allows a direct access to spatially resolved molecular and structural information of the analyzed area. The image contrast is generated on the basis of the tissue's intrinsic biochemical composition. The current investigation shows how mid infrared microspectroscopic mapping and imaging is used for the bio-analytical characterization and identification of specific molecular components of a tissue sample at high lateral resolution of a few microns (approaching the mid infrared diffraction limit). Furthermore, the potential of these methods for monitoring the penetration and distribution of drugs within biological tissues are presented. Due to the fact, that mid infrared microspectroscopy is a noninvasive, nondestructive technique for the analyzed sample, requiring no complicated and time consuming staining procedures, it is a convenient method for histological and pathological investigations, allowing the generation of a huge amount of biochemical information not yet available with other nonvibrational techniques. The strength of the presented microscopic technique is the fact that the infrared images are directly comparable to outcomes of classical histological staining procedures and can be interpreted by nonspectroscopists.     

电机表面过热故障的红外成像监测诊断

分析了引起电机表面温度过高的原因,用红外热成像方法对某船用电机过热故障进行了监测诊断,总结了用红外热像方法测量电机表面温度时要注意的问题。     

Hydrogen production from acid- and ammonia-pretreated biomass

Hydrogen production from biomass has potential environmental and economic advantages; however, the factors that lead to low hydrogen production should be investigated. Acid and base pretreatments were applied to investigate the catalytic effects of alkali and alkaline earth metals (AAEMs) on the biomass (wood pellets) samples and hydrogen production through pyrolysis. The pyrolysis behavior and gas yield were analyzed using a thermogravimetric analyzer and drop tube furnace, respectively. The chemical structure characteristics were analyzed using Brunauer-Emmett-Teller specific surface area analyzer, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Chemically pretreated samples yielded considerably higher hydrogen than the raw sample, as confirmed based on the microstructural properties of the biochar samples. Therefore, the physical changes produced a greater effect than the chemical changes caused by the removal of AAEMs.