用紫外光谱和X射线光电子能谱研究金属卟啉自组装膜

金属卟啉化合物由于具有丰富的电子结构和特殊的物理化学性质,因而在光电材料、分子器件和非线性光学等领域具有广阔的应用前景．有机硅可用于提高高分子化合物在氧化物基底表面的附着力;在气相和液相色谱中可作为固定相;在生物传感器中可用于蛋白质的固定．     

成像X射线光电子能谱定量分析研究

探索了直接用实验测得的XPS图像强度来做元素或化学态相对定量分析的可能性。以AgCl和Na2S2O3样品为例，实验结果表明：XPS图像强度与成像时间有良好的线性关系，根据图像强度对两种元素或化学态进行相对定量是可能的。     

X射线光电子能谱法分析爆炸残留物

提出了用X射线光电子能谱法(XPS)对某爆炸案件的爆炸残留物进行定性、定量分析,同时以X射线荧光光谱仪(XRF)、扫描电镜能谱仪(SEM/EDX)为辅助测试手段,判断为氯酸盐类炸药,所用炸药为烟火剂。结果表明:XPS可以无损、快速地检测出无机爆炸残留物的元素成分及含量,并确定主要爆炸成分的化学式,进而确定罪犯所用炸药的种类,为侦破案件提供线索。     

砷化镓半导体表面自然氧化层的X射线光电子能谱分析

用X射线光电子能谱(XPS)，测量了Ga3d和As3d光电子峰的结合能值，指认了砷化镓(GaAs)晶片表面的氧化物组成，计算了表面氧化层的厚度，定量分析了表面的化学组成；比较了几种不同的砷化镓晶片表面的差异。结果表明：砷化镓表面的自然氧化层主要由Ga2O3、As2O5、As2O3和单质As组成，表面镓砷比明显偏离理想的化学计量比，而且，氧化层的厚度随镓砷比的增大而增加；溶液处理后，砷化镓表面得到了改善。讨论了可能的机理。     

X射线光电子能谱仪的开放使用与管理

X射线光电子能谱仪(XPS)是材料表面元素定性和半定量分析的重要手段之一,是表面分析科研工作的必备仪器.为提高测试效率,实施了大型仪器设备开放共享优化,总结了在推动XPS开放过程中管理的经验和体会.     

电化聚合聚吡咯的角分布X射线光电子能谱研究

用角分布Ｘ射线光电子能谱（ＸＰＳ）测试和样品原位加热相结合的方法研究了阴离子是对甲苯磺酸根的电生导电聚吡咯的化学和聚集态结构．其结果表明聚吡咯表面约几个原子层内原子的相对浓度依下述次序递减：Ｃ＞Ｏ＞Ｓ＞Ｎ；导电聚吡咯中的氮原子至少有吡咯氮和氧化态氮两种；在２００℃加热以后聚合物链不受影响，但阴离子向表面迁移，同时氧化态氮大大减少．     

匀胶铬版表面界面微观构成的X射线光电子能谱表征

用Ｘ射线光电子能谱（ＸＰＳ）研究了几种不同工艺制备的匀胶铬版表面、铬膜内部以及各层之间界面处的微观化学组成和化学状态，讨论了不同工艺对铬版材料微观构成及宏观特性的影响。     

利用X射线光电子能谱研究马家塔煤显微组分中氧的赋存形态

煤中氧的赋存形态是煤结构研究的重要内容,煤炭加工转化（如煤的热解、直接加氢液化等）也需要确实详尽的煤中氧赋存形态的数据信息。x射线光电子能谱法（x—ray Photoelectron Speetroscopy,XPS）是近年来新出现的最有效的元素分析方法之一,目前,已在化学、物理、生物等各个领域中得到广泛应用。1974年,XPS分析方法首次用于煤的研究,近年来,XPS成为研究煤中硫和氮存在形态的有效方法之一。许多学者在煤中无机矿物中碳、氧、硫的存在形态及XPS直接测定煤中有机硫等方面做过较多研究工作,但由于煤结构的复杂性、实验条件不尽相同以及煤中矿物的干扰等,以往的研究结果并不完全相同。     

X射线光电子能谱研究低温氧等离子体对棉纤维表面改性

本文叙述了用X射线光电子能谱(XPS)表征棉纤维的表面特性,比较了不同方法处理的棉纤维的表面改性。还讨论了等离子体对棉纤维的润湿性和脱脂作用机理。实验表明:刻蚀、氧化、分裂和接枝含氧基团是低温氧等离子体对棉纤维表面的主要作用。     

X射线光电子能谱技术在高分子材料摩擦化学研究中的应用

X射线光电子能谱技术(XPS)是材料表面分析的重要手段,其近年的快速发展促进了表面化学领域研究的深入.高分子及其复合材料在摩擦学性能方面具有普遍的优势,通过XPS对高分子及其复合材料摩擦表面的分析,可以确定摩擦过程的化学变化,并对改进材料的摩擦学性能起到理论的指导作用.作者主要介绍XPS技术的基本原理,及其在高分子与复合材料摩擦学性能研究中的应用.     

Chemical Characterization of Kraft Lignin Prepared from Mixed Hardwoods

Chemical characterization of kraft lignin (KL) from mixed hardwoods (Acacia spp. from Vietnam and mixed hardwoods (mainly Quercus spp.) from Korea) was conducted for its future applications. To compare the structural changes that occurred in KL, two milled wood lignins (MWLs) were prepared from the same hardwood samples used in the production of KL. Elemental analysis showed that the MWL from acacia (MWL-aca) and mixed hardwood (MWL-mhw) had almost similar carbon content, methoxyl content, and C₉ formula. KL had high carbon content but low oxygen and methoxyl contents compared to MWLs. The C₉ formula of KL was determined to be C₉H_7.29O_2.26N_0.07S_0.12(OCH₃)_1.24. The M_w of KL and MWLs was about 3000 Da and 12,000–13,000 Da, respectively. The structural features of KL and MWLs were investigated by Fourier transform infrared spectroscopy (FT-IR) and nuclear magnetic resonance spectrometry (¹H, ¹³C NMR). The analyses indicated that KL underwent severe structural modifications, such as γ-carbon cleavage, demethylation, and polycondensation reactions during kraft pulping, which resulted in increased aromatic content and decreased aliphatic content. The main linkages in lignin, β-O-4 moieties, were hardly detected in the analysis as these linkages were extensively cleaved by nucleophilic attack of SH^- and OH^- during pulping.     

用FTIR和XPS研究ACF的表面结构

采用红外光谱（FTIR）及X光电子能谱（XPS），系统分析了纤维碳化各阶段的结构、不同程度活化的ACF的结构以及低温氧化后和热处理后ACF的结构，提出了ACF表面结构模型。     

A guide for the meaningful surface analysis of wood by XPS and ToF-SIMS

The surface analysis of wood and wood products is becoming increasingly important for reasons ranging from the investigation of molecular constituents through to the optimization of industrial processes. As with any natural product, wood analysis is not straightforward, and this review aims to provide guidance for the successful surface analysis of wood by XPS and ToF-SIMS. Through example experiments, three themes are addressed relevant to obtaining meaningful results: considerations related to heterogeneity in the composition of wood (e.g., growth rings); the impact of the chemical removal of minor wood components known as extractives, and whether such a process is necessary; and the potential for misleading or erroneous results as a result of contamination occurring during sample preparation. In addition to discussing successful sample preparation approaches, the important role to be played by MVA in surface analysis is emphasized, particularly in the analysis of ToF-SIMS data. Examples of ToF-SIMS/MVA are provided that highlight the identification of contamination in sample preparation, the quantification of wood composition in terms of cellulose and lignin, and the indication of age of softwood samples. Through consideration of the complexities that influence wood surface analysis, the design and interpretation of consequential experiments become easier and more accurate.     

Characterization of Au-Rh/TiO2 catalysts by CO adsorption; XPS, FTIR and TPD experiments

On X-ray photoelectron spectra of the Au-Rh/TiO₂ catalysts the position of Au4f peak was practically unaffected by the presence of rhodium, the peak position of Rh3d, however, shifted to lower binding energy with the increase of gold content of the catalysts. Rh enrichment in the outer layers of the bimetallic crystallites was experienced. The bands due to Au⁰-CO, Rh⁰-CO and (Rh⁰)₂-CO were observed on the IR spectra of bimetallic samples, no signs for Rh⁺-(CO)₂ were detected on these catalysts. The results were interpreted by electron donation from titania through gold to rhodium and by the higher particle size of bimetallic crystallites.     

XPS characterization of wood chemical composition after heat‐treatment

XPS was used to characterize the chemical changes occurring after drying or applying a heat‐treatment to beech wood samples. Our results indicate that the surface of this air‐exposed material could be strongly affected either by the ambient atmosphere during storage or by the complex atmosphere in the oven during drying or heat‐treatment. However, the O/C ratio measured after removal of a thin slice of a few millimetres of an untreated sample is in reasonable agreement with that calculated from the well‐established chemical composition of beech. Through this methodology (equivalent to scraping for hard materials) it is expected to get a realistic characterization of the wood. The reliability and repeatability of the XPS measurements have been checked and the method applied to the study of the chemical changes of the beech samples subjected to heat‐treatment. Heating at 240 °C induces a significant decrease of the O/C ratio from 0.55 before to 0.44 after the treatment. Heat‐treatment induces also a decrease of the C₂ carbon contribution (carbon atom bound to a single non‐carbonyl oxygen) associated with an increase of the C₁ carbon contribution (carbon atoms bound only to carbon or hydrogen atoms), in agreement with chemical modifications reported previously in the literature. Thanks to the small analysed area of the equipment used in this study, different spots were analysed to demonstrate the presence or absence of a gradient of chemical composition due to thermal degradation or migration of extractives from within the wood structure to its surface. At the scale of our observations, the different wood samples investigated (dried or heat treated) appear to be homogeneous. Copyright © 2006 John Wiley & Sons, Ltd.     

Lignin and Lignin-Derived Compounds for Wood Applications—A Review

Improving the environmental performance of resins in wood treatment by using renewable chemicals has been a topic of interest for a long time. At the same time, lignin, the second most abundant biomass on earth, is produced in large scale as a side product and mainly used energetically. The use of lignin in wood adhesives or for wood modification has received a lot of scientific attention. Despite this, there are only few lignin-derived wood products commercially available. This review provides a summary of the research on lignin application in wood adhesives, as well as for wood modification. The research on the use of uncleaved lignin and of cleavage products of lignin is reviewed. Finally, the current state of the art of commercialization of lignin-derived wood products is presented.     

Experimental Researches on Milled Wood Lignin Pyrolysis Based on Analysis of Bio-oil

The structure of milled wood lignin(MWL), isolated via the Bjrkman procedure, was studied by means of 1H NMR spectroscopy and Fourier transform infrared spectroscopy, and then its pyrolytic product distribution was investigated on a pyrolysis device. MWL obtained from Manchurian Ash(MA) contained more methoxyl and free phenolic hydroxyl groups per C9 unit than MWL from Mongolian Pine(MP) due to the existence of both guaiacyl and syringyl units, which have a major influence on the pyrolysis behavior of lign...     

Functionalization by Cold Plasmas of Polymer Model Surfaces (Hexatriacontane and Octadecyloctadecanoate) Studied by Contact Angle Measurements,XPS, and FTIR Spectroscopy

Abstract

Surface functionalization by argon or oxygen RF plasmas (13.56 MHz) of polymer model compounds, namely hexatriacontane (C₃₆H₇₄) and octadecyloctadecanoate [OOD, CH₃(CH₂)₁₆COO(CH₂)₁₇CH₃, was studied using contact angle measurements, XPS, and FTIR-ATR. In order to gain a better insight into the plasma-surface interaction mechanisms, the effects of the main plasma parameters (treatment time, power, pressure, and flow rate) on functionalization were investigated. It was shown that an argon plasma is more efficient than an oxygen plasma and that the ester-containing model compound incorporated less oxygen than the paraffinic one. After 10 seconds of treatment, contact angle measurements showed that none of these plasma parameters affect in any way the properties of the uppermost surface layer; these depend only on the nature of the sample and on the gas used in the plasma. On the other hand, ESCA, which allows a 70-Å in-depth probing, reveals the influence of the plasma parameters on both types of samples. IR, which probes to a much greater depth, evidences an evolution only for treated OOD samples. Interpretations are proposed for the effect of the plasma parameters on functionalization.     

Monitoring Fibre Surfaces with XPS in Papermaking Processes

 Recent instrumental advances have vastly improved the analysis power of X-ray photoelectron spectroscopy (XPS), which has been widely used in applied surface research for decades. In this presentation a set of XPS analysis methods well suited for problems and analytical needs encountered in papermaking technology is presented. The emphasis will be on analysis of pulps and non-coated papers. Examples given describe the use of XPS in quantification of surface lignin and extractives; an alternative approach for evaluating elemental surface distributions via the Tougaard background analysis is also presented. The experimental work and interpretations presented are based on more than two thousand XPS analyses performed at Helsinki University of Technology during 1996–2000. With strictly standardised experimental setup, state-of-the-art instrumentation and a proper combination of analysis methods XPS can yield valuable and consistent information on surface properties of natural fibers.     

Polyaniline/lignin blends: FTIR, MEV and electrochemical characterization

Blends of polyaniline (emeraldine base) and Eucalyptus grandis kraft lignin were prepared by casting method. The maximum amount of lignin that could be used for blending was 36% (w/w); beyond that, fractile films were produced. The IR spectra of the blends indicated that interactions occurred between polyaniline and lignin. Cyclic voltammetry measurements showed peaks that were readily attributed to the oxidation/reduction of polyaniline and a new oxi-reduction peak due to oxidation/reduction of sites created during interaction of two polymers. Scanning electronic microscopy showed that all blends were homogeneous.