表面增强拉曼光谱在工业水处理及金属材料保护中的应用

表面增强拉曼光谱SERS广泛地用于各种物质在金、银、铜等贵金属表面的吸附机理研究 ,而实际应用中更需要的是铁铝等金属 ,尤其是含铁材料的SERS研究。很多含硫化合物是工业水处理和材料保护中铁的良好缓蚀剂。本工作尝试用表面增强拉曼光谱研究了苄基双硫化合物在铁表面的吸附状态 ,获得了很好的增强效应 ,为拓展拉曼光谱的应用提供了一个很好的途径。     

表面增强拉曼光谱有工业水处理及金属材料保护中的应用

表面增强拉曼光谱SERS广泛地用于各种物质在金,银,铜等贵金属表面的吸附机理研究,应实际应用中现需要的是铁铝等金属,尤其是含铁材料的SERS研究,很多含硫化合物是工业水处理和材料保护中铁的良好缓蚀剂,本工作尝试用表面增强拉曼光谱研究了苄基双硫化合物在铁表面的吸附状态,获得了很好的增强效应,为拓展拉曼光谱的应用提供了一个很好的途径。     

大孔径内孔表面金刚石薄膜涂层的制备

应用热丝化学气相沉积（HFCVD）工艺,并采用合适的衬底预处理方法和优化的工艺参数,在大孔径硬质合金内孔表面沉积了金刚石薄膜。分别采用SEM、EDS和喇曼光谱依次对衬底预处理前后内孔表面及沉积的金刚石薄膜进行了表征,并通过压痕实验评估了薄膜的附着强度。该压痕实验结果与薄膜的SEM及喇曼光谱表征的结果具有一致性。结果表明：采用合适的衬底预处理方法和优化的HFCVD工艺,可以在大孔径硬质合金内孔表面沉积高质量的金刚石薄膜。     

金刚石微粉的喇曼光谱

近年来,金刚石不仅用于装饰品的加工,而且在切削工具、涂膜、散热板、扬声器上的振动板、光学窗口等各方面均得以广泛应用.喇曼分光法广泛用于金刚石膜的结晶性和变形量的评估.膜厚度如果变薄,由于变形,就会增加喇曼曲线的移动.而且,由于尺寸效应,其影响就会体现在喇曼波谱中.为了正确地评估变形量,有必要知道由于尺寸效     

过滤式阴极电弧沉积类金刚石薄膜的性能分析

成功地研制了一套过滤式阴极电弧沉积设备,并利用该设备成功获得了类金刚石薄膜。类金刚石薄膜的扫描电镜分析表明：获得的薄膜在硅基片上是光滑和致密的,在Ｔｉ合金基片上有裂纹,高速钢基片上有微孔。原子力显微镜分析表明：膜层的表面粗糙度与沉积参数密切相关。喇曼光谱研究表明,这种薄膜是典型的无氢类金刚石薄膜,喇曼光谱的高斯分解表明：随着偏压的变化,Ｄ线和Ｇ线的位置μＤ、μＧ向低频移动,半高宽σＤ减小。     

侯马陶范表层处理技术初探

为了解部分陶范表面存在的未知用途的黑灰层物质的组成和作用,呆用了红外光谱（FTIR）、X射线荧光（XRF）、X射线衍射（XRD）、喇曼光谱（RAM）等分析方法对其进行了综合测试研究,对陶范表面黑灰层的组成和物相进行了较深入分析,揭示出黑灰层形成的3种成因。     

表面增强拉曼光谱用于不锈钢缓蚀机理的研究

本文运用表面增强拉曼散射光谱(SERS)技术,研究在0.5%HCl体系中缓蚀剂在18—8不锈钢表面的吸附模式。这些SERS谱图是籍在不锈钢表面电沉积不连续Ag颗粒得到的。缓蚀剂BMAT在电极表面的吸附是通过电极表面与缓蚀剂中的N原子形成化学吸附,以及苯并咪唑环的共轭大π键的化学吸附,缓蚀剂斜卧于电极表面。BMAT的烯两基起到空间阻碍的作用。     

硫脲和尿素在银电极上吸附行为的电化学和SERS研究

利用表面增强拉曼光谱(SERS)和极化曲线的方法研究了硫脲和尿素在H2SO4溶液中银电极上的吸附行为.结果表明:硫脲参与了银的阳极溶解反应.尿素在银电极表面上发生了缩合反应,产物为缩二脲,缩二脲以质子化的形式物理吸附在银表面上     

铜表面吡咯烷二硫代氨基甲酸铵自组装膜的拉曼光谱和缓蚀作用

应用表面增强拉曼光谱(SERS)和电化学方法,对铜电极表面吡咯烷二硫代氨基甲酸铵(APDTC)的自组装单层结构、缓蚀性能和吸附行为进行研究。SERS光谱表明:APDTC分子通过硫原子垂直吸附在铜表面形成APDTC自组装单分子膜(APDTC SAMs)。交流阻抗和极化曲线实验表明:在3%NaCl(质量分数)溶液中APDTC SAMs对铜具有很好的缓蚀作用,最高缓蚀效率可达98%;APDTC的吸附行为符合Langmuir吸附等温式,吸附机理是介于化学吸附和物理吸附之间的一种吸附。     

陈化胶体金的简便合成与光谱特性

文章描述了通过只添加氢氧化钠到氯金酸和十六烷基三甲基溴化铵混合液中合成陈化纳米金胶体,并研究了该胶体的光谱特性。基于傅里叶红外光谱对纳米金的形成机理进行了分析并以紫外可见光谱和扫描电子显微镜表征了添加不同量的氢氧化钠而获得的陈化三个月的胶体金。同时文章获得了吸附于陈化了三个月的胶体金表面上的亚甲基蓝的表面增强拉曼光谱。结果表明,陈化三个月的胶体金其紫外可见光谱具有宽的等离子吸收峰,这种宽化改变在文章对中进行了解释分析。其透射电子显微镜图片表明了在纳米金合成阶段,添加不同量的氢氧化钠可影响纳米金大小,同时不同量的氢氧化钠影响着胶体金的陈化过程并产生出形状依赖的陈化胶体金。表面增强拉曼光谱的增强特性不同证明了所形成的陈化胶体金的大小/形状依赖特征。因此,我们期望着这种陈化胶体金能够在生化分析领域被得到开发应用。     

甲烷浓度对批量生产金刚石涂层刀片的影响

采用微波等离子体CVD(MWCVD)法小批量地生产了金刚石涂层刀片,在金刚石薄膜沉积的过程中,研究了碳源浓度对沉积金刚石膜的均匀性的影响。用扫描电子显微镜(SEM)和激光拉曼光谱(Raman)对薄膜的表面形貌和质量进行了表征。结果表明较低的低甲烷浓度适合金刚石涂层刀片的批量生产。     

Laser Raman microscopic studies of passive films formed on type 316LN stainless steels during pitting in chloride solution

The surface films formed on type 316LN stainless steels (SS) with different nitrogen contents, during potentiodynamic polarization in acidified 1 M NaCl solution, were characterized by Laser Raman Spectroscopy (LRS). LRS confirmed the presence of oxides and oxychlorides of iron and chromium, hydrated chlorides and nitrates in the film. Raman mapping showed increasing nitrate content in the film with increasing nitrogen content. The film on the uncorroded material showed the presence of chromium and molybdenum oxides. The improvement in pitting corrosion resistance of type 316LN SS with increasing nitrogen content was attributed to increased amount of nitrates in the passive film.     

A SERS investigation of carbon steel in contact with aqueous solutions containing BenzylDiMethylPhenylAmmonium Chloride

The electrochemical behaviour of carbon steel in contact with a neutral sulphate solution containing BenzylDiMethylPhenylAmmonium Chloride (BDMPAC), a potential non‐toxic corrosion inhibitor was investigated by Surface Enhanced Raman Spectroscopy (SERS) and linear sweep voltammetry. Sound surface enhancement was obtained by potentiostatic polarisation without special electrochemical pretreatments. Potential‐dependent Raman spectra highlighted the electrodic behaviour of the adsorbate: in the range ? 1200 ÷ ? 900 mV (Ag/AgCl), adsorption takes place with the benzyl ring interacting with the surface in a flat configuration, as indicated by the presence of the Ph‐CH₂ combination band located near 1215 cm^?1. Linear sweep voltammetry testifies the difference in measured currents between sulphate containing solutions in the absence and the presence of BDMPAC at the adsorption potentials. The formation of iron corrosion products was easily detected by in situ Raman spectroscopy.     

Role of tannic acid based rust converter on formation of passive film on zinc rich coating exposed in simulated concrete pore solution

Pretreatment of reinforcement steel surface with tannic acid based rust converter (RC) prior to the application of zinc rich coating (ZRC) is observed to improve its corrosion resistance appreciably. This improvement is caused due to decrease of pH of the corroding interface as a result of outward diffusion of acidic components of RC from the converted rust layer. The decrease in pH of corroding interface brings the ZRC in the protective pH range of Zinc and accelerates the formation of passive layer. This layer is identified as Hydrozincite (HZ). Electrochemical Impedance Spectroscopy (EIS), Potential-time studies, Raman Spectroscopy, Scanning electron Microscopy (SEM), energy dispersive X-ray analysis (EDXA) and X-ray diffraction studies have been performed to understand the mechanism and kinetics of the film formation.     

CuIn0.7Ga0.3Se2粉末的自蔓延高温合成

以Cu,In,Ga,Se单质为原料用自蔓延高温合成法制备CuIn0.7Ga0.3Se2粉末.通过X射线衍射、光电子能谱、能量散射X射线分析、激光拉曼光谱等分析方法对产物的组成、结构和成分进行表征.结果表明,反应物投料比例,合成气氛压力等因素对合成产物化学计量配比有显著的影响.利用自蔓延高温合成方法可以获得精确化学计量配比、单相黄铜矿结构的CuIn0.7Ga0.3Se2.     

Chemical and mechanical properties of anodized cp-titanium in NH4 H2PO4/NH4F media for biomedical applications

Potentiostatic anodizing of commercially pure titanium, using ammonium phosphate and ammonium fluoride solution as electrolyte is studied. The objective is to generate titanium oxides on the surface and phosphor compounds presenting good protective and mechanical properties, and proper adhesion to the metal substrate to remain during surgical orthopedic procedures (implants). Two different applied potentials were used to obtain different surface oxides morphologies (20 and 30 V). The characterization and quantification of the generated deposits is presented as a starting point for the future application of these composite types of materials. X-ray Photoelectron Spectroscopy (XPS) and Raman spectroscopy techniques showed the presence of phosphor compounds and anatase (TiO₂) as the main constitutive phases.     

Influence of substrate surface topography in the deposition of nanostructured diamond-like carbon films by high density plasma chemical vapor deposition

In this work, we have studied the influence of the substrate surface condition on the roughness and the structure of the nanostructured DLC films deposited by High Density Plasma Chemical Vapor Deposition. Four methods were used to modify the silicon wafers surface before starting the deposition processes of the nanostructured DLC films: micro-diamond powder dispersion, micro-graphite powder dispersion, and roughness generation by wet chemical etching and roughness generation by plasma etching. The reference wafer was only submitted to a chemical cleaning. It was possible to see that the final roughness and the sp³ hybridization degree strongly depend on the substrate surface conditions. The surface roughness was observed by AFM and SEM and the hybridization degree of the DLC films was analyzed by Raman Spectroscopy. In these samples, the final roughness and the sp³ hybridization quantity depend strongly on the substrate surface condition. Thus, the effects of the substrate surface on the DLC film structure were confirmed. These phenomena can be explained by the fact that the locally higher surface energy and the sharp edges may induce local defects promoting the nanostructured characteristics in the DLC films.     

The development of low-temperature hardening silicone ceramer coatings for the corrosion protection of metals

The process parameters for the formulation of two different hybrid ceramic-polymer (ceramer), barrier-type coatings for the corrosion protection of metals are discussed. The coating formulations were characterized in the liquid, gel, and solid phases using Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy and Secondary Ion Mass Spectroscopy (SIMS), respectively. The coatings were applied to 6061-T6 aluminum alloy, hardened in ambient conditions, and analyzed with X-ray photoelectron spectroscopy (XPS). Thermal stability of the coatings was analyzed in inert and oxidative atmosphere using thermogravimertic analysis. The final surface morphology was studied using Scanning Electron Microscope (SEM) and Atomic Force Microscopy (AFM). The nanoindentation technique supported by SEM revealed the nanomechanical properties of the coatings. The effectiveness as a barrier-type coating was studied using electrochemical polarization experiments and immersion experiments in saline solution.     

Zirconia Layer Formed by High Temperature Oxidation of Pure Zirconium: Stress Generated at the Zirconium/Zirconia Interface

Oxidation of pure zirconium metal at high temperature (500 and 600 °C) under air at normal atmospheric pressure was investigated using the Raman Spectroscopy technique. Analysis of the absolute intensities as well as the positions of the Raman bands for the tetragonal and the monoclinic zirconia phases was performed. Evolution of the thermal stress has been presented and discussed in comparison to the Raman mode shift recorded in situ during cooling. Ex-situ analyses of cross-sections confirm the presence of tetragonal phase preferentially located close to the metal/oxide interface and show the existence of a relaxed and highly disordered tetragonal phase preferentially located in the outer part of the scale. Using a micro tension––compression machine, it is shown that compression loads lead to a significant intensity change of the Raman peaks for the tetragonal zirconia. The effect of tension load appears less clear which demonstrates that the relation between Raman peak shift and stress is not as simple as generally considered.     

MDHTD对SRB生物膜的剥离作用及对碳钢的吸附作用研究

利用交流阻抗(EIS)、原子力显微镜(AFM)和X射线光电子能谱(XPS)等方法研究了在高矿化度盐水介质中含咪唑杂环的双季铵盐化合物MDHTD对硫酸盐还原菌（SRB）生物膜的剥离和在Q235钢表面的吸附作用.结果表明：在高矿化度盐水中,MDHTD在碳钢表面的吸附抑制了SRB在金属基体表面的生长代谢过程,对SRB生物膜具有良好的渗透和剥离作用,使生物膜电阻显著降低;由于MDHTD在金属基体表面的吸附,双电层电容值和腐蚀反应的电荷传递电阻都有升高的趋势.