Thin film of bis(ethylenedithio)-tetrathiafulvalene radical salt with Dawson polyoxometalate

The thin film of bis(ethylenedithio)-tetrathiafulvalene (BEDT-TTF or ET) radical salt with Dawson polyoxometalate [P₂W₁₈O₆₂]⁶⁻ was prepared on gold substrate by using electrochemical process. The film was characterized by Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), electron spin resonance spectroscopy (ESR) and cyclic voltammetry (CV). Scanning electron microscope (SEM) micrograph of the film exhibits a smooth and uniform surface layer containing micronic grains. The thickness of the film estimated by SEM is ca. 22 μm. The film exhibits semiconducting behavior with a room-temperature conductivity 6.5 × 10⁻³ S cm⁻¹.     

TiO2纳米复合薄膜制备及光催化性能研究

用浸渍提拉法在玻璃基片上制备TiO2纳米薄膜和TiO2／ZnFe2O4纳米复合薄膜，利用X射线衍射(XRD)、扫描电镜(SEM)、原子力显微镜(AFM)、X射线光电子能谱(XPS)以及紫外．可见分光光度计等分析测试方法对制备薄膜的相结构及光吸收性能进行了分析和表征。结果表明，在500℃热处理下薄膜为锐钛矿型，粒度在20nm～30nm；复合后薄膜的光吸收边发生了红移，不同的复合方式影响亚甲基蓝染料的光催化降解效率。     

Preparation of TiO2/PANI composites in the presence of surfactants and investigation of electrical properties

“In situ” polymerization was carried out in the presence of titanium dioxide (TiO₂) to synthesize TiO₂/polyaniline (TiO₂/PANI) composite in an aqueous medium containing anionic (sodium dodecylbenzenesulfonate), DBSNa, cationic (tetradecyltrimethylammonium bromide), TTAB, and nonionic surfactants (poly(ethylene oxide) (20) sorbitan monolaurate), Tween 20). The composites were characterized by FTIR, UV–vis spectroscopy, scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and Gouy balance measurements. The FTIR and UV–vis spectra reveal that the interaction between TiO₂/PANI composite and surfactants. The anionic and cationic surfactants incorporated with TiO₂/PANI composite structure. The stability of the composites in terms of direct-current electrical conductivity retention was studied in isothermal conditions. Electrical conductivity measurements indicate that the conductivity of TiO₂/PANI synthesized in the presence of the cationic surfactant has the highest conductivity value. All composites showed negative mass magnetic susceptibility values.     

Synthesis and characterization of polythiophenes prepared in the presence of surfactants

In this study homopolymers of thiophene were synthesized by chemical oxidative polymerization in the presence of three different surfactants (anionic, cationic and non-ionic) and an oxidant in an anhydrous medium. An anionic surfactant, sodium dodecylbenzenesulfonate (DBSNa), a cationic surfactant, tetradecyltrimethylammonium bromide (TTAB) and a non-ionic surfactant, poly(ethylene oxide) (20) sorbitan monolaurate (Tween 20), were used as additives. The properties of the polythiophenes (PTs) prepared were studied and compared with those of surfactant-free polythiophene (PT). PTs were characterized by different techniques: FTIR spectroscopy, elemental analysis, scanning electron microscopy, thermogravimetry and conductivity measurement. The scanning electron micrographs of PT prepared in the presence of surfactants showed differences in the surface morphologies for different surfactants. PT prepared in the presence of cationic and non-ionic surfactants exhibited smooth surfaces, while a typical globular structure was found for surfactant-free PT. PT synthesized with a cationic surfactant showed the highest thermal stability of all the samples.     

基体对金刚石厚膜质量的影响研究

采用MPCVD法在钼基体上制备金刚石厚膜,测量了等离子体发射光谱,并利用XPS、Raman和SEM对金刚石厚膜进行表征.研究了Mo原子进入金刚石中的机制及其对金刚石厚膜的影响.结果表明:除了热扩散,Mo原子还会以蒸发进入等离子体的方式进入金刚石.金刚石中的Mo原子是以Mo+4、Mo+6以及介于Mo+4-Mo+6之间的化...     

Preparation and characterization of PAn/NiO nanocomposite using various surfactants

Conducting nanocomposite of NiO–PAn has been prepared in the aqueous medium using polyvinyl alcohol and hydroxypropylcellulose as a surfactant. The conductivity of the composites was measured as a function of the NiO concentration in reaction solution. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) and electrical resistivity proved that NiO affect the properties of composite.     

Detection of chemical warfare agent Nitrogen Mustard-1 based on conducting polymer phthalocyanine nanorod modified electrode

A simple method is reported for the detection of chemical warfare agent Nitrogen Mustard-1 (NM-1) by using a modified electrode which was prepared by electrochemically immobilizing copper phthalocyanine (CuPc) into polypyrrole (pPy) in presence of a cationic surfactant cetyltrimethylammonium bromide (CTAB) during the polymerization of pyrrole in an aqueous solution. The surface of the modified and bare electrodes are characterized by scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS) techniques in order to know the surface morphology and elemental composition of the modified electrodes, respectively. SEM images indicated the presence of nanorods on pPy/CuPc/CTAB sample and EDS study confirmed the nanorods as CuPc. Moreover, EDS study confirmed that the nanorods are only on the pPy matrix and not inside the pPy. FTIR results confirmed the presence of CuPc in pPy film. AC impedance spectroscopy analysis of the modified electrode with NM-1 exhibited more electron transfer resistance. The prepared modified electrode showed good electrochemical activity with NM-1 when compared to the unmodified gold electrode.     

The mechanism of inhibition by zinc phosphate in an epoxy coating

Epoxy coatings containing different volume fractions of zinc phosphate have been successfully prepared and their inhibitive properties have been studied by electrochemical impedance spectroscopy (EIS) and immersion tests. The results show that zinc phosphate can improve the protection ability of epoxy coatings and its best volume fraction is 30%. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) results indicate that the presence of zinc phosphate can form an inhibiting film which is composed of the phosphating film of FePO₄, Fe₂O₃, and FeO, as well as the shielding film of zinc phosphate on the steel surface.     

Polythiophene/SiO2 nanocomposites prepared in the presence of surfactants and their application to glucose biosensing

Conducting polythiophene/SiO₂ (PT/SiO₂) nanocomposites were prepared in the presence of three different surfactants (anionic, cationic and non-ionic) via chemical oxidative polymerization in an anhydrous medium to create an enzyme-immobilized polymeric amperometric biosensor. An anionic surfactant, sodium dodecylbenzenesulfonate (DBSNa), a cationic surfactant, tetradecyltrimethylammonium bromide (TTAB), and a non-ionic surfactant, poly(ethylene oxide) (20) sorbitan monolaurate (Tween 20), were used as additives. The properties of the nanocomposites were investigated, as a function of surfactant type and the amount of PT contained, by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The SEM results reveal that all PT/SiO₂ samples form nanometer-dimensioned globular structures. The highest conductivity obtained was 2.7 × 10⁻² S cm⁻¹ for a PT/SiO₂-Tween 20 nanocomposite. Thermogravimetric analysis (TGA) shows that the residue decreases with increasing amount of PT. Glucose oxidase (GOX) was immobilized by crosslinking to the conducting PT/SiO₂ composites and was used for amperometric detection of glucose.     

Synthesis and characterization of Ag@polycarbazole coaxial nanocables and their enhanced dispersion behavior

Ag@polycarbazole coaxial nanocables (CNCs) have been successfully fabricated by the oxidative polymerization of carbazole over Ag nanowires (NWs) in acetonitrile. The morphology of Ag NWs and CNCs was studied by employing a transmission electron microscope (TEM) and a scanning electron microscope (SEM), which showed them to be a monodisperse material. The thickness of the polymer sheath was found to be 5 nm to 8 nm by observation under a high-resolution transmission electron microscope (HR-TEM). Energy dispersive X-ray spectroscopy (EDS), FT-IR and Raman measurements were used to characterize the polymer sheath, which demonstrated it to be a carbon material in polycarbazole form. X-ray photoelectron spectroscopy (XPS) was used for an interfacial study, which revealed that Ag surface atoms remained intact during polymer growth. In the end, zeta potential showed that the dispersion stability of Ag NWs increased due to polymer encapsulation, which is significant to obtain a particular alignment for anisotropic measurement of electrical conductivity.     

Formation mechanism of phosphate conversion film on Mg-8.8Li alloy

A novel phosphate conversion film was obtained on Mg-8.8Li alloy. The film formation mechanism was studied by electrochemical measurements, scanning electron microscopy (SEM) observation and X-ray photoelectron spectroscopy (XPS) analysis. The deposition of conversion film contained three stages. Stage I: loose surface film consisting of oxides and hydroxides was dissolved to expose the bare substrate. Stage II: β phase was preferentially dissolved, accompanying with the deposition of conversion film, and then α phase was deposited with conversion film. Stage III: conversion film was gradually improved until the dynamic balance of film dissolution and formation was established.     

银纪念币的腐蚀变色研究

银纪念币在大气环境中表面发生变色，失去原有的金属光泽。采用OM，SEM，EMPA，XPS，XRD等现代物理测试技术对变色的银纪念币进行分析。结果表明，银纪念币的变色部位呈均匀的浅褐色，并随机分布着深褐色的斑点。变色银纪念币表面沿着划痕密集分布着蚀孔。表面分析显示，除Ag外，还有S和O元素。XPS，XRD分析发现，变色银纪念币表面存在Ag2S，Ag2SO3和Ag2O。实验室加速变色试验毒明，在含S气体环境中，Ag被氧化生成A82S，导致银纪念币表面变色,从而验证银纪念币的变色是由电化学腐蚀引起的，S和O元素参与了腐蚀历程。     

纳米植酸锌缓蚀效果及其复合环氧涂层的防护性能

目的 考察NaCl溶液中植酸锌对Q235的缓蚀效果及其复合环氧涂层的防护性能。方法 以植酸钠和乙酸锌为原材料成功制备纳米植酸锌,并通过红外光谱仪（IR）、扫描电子显微镜（SEM）、电子能谱仪（EDS）、透射电子显微镜（TEM）及X射线衍射仪（XRD）对其结构及形貌进行表征。采用开路电位、极化曲线、X射线光电子能谱技术（XPS）及SEM等手段,研究了Q235在含植酸锌浸出物的Na Cl溶液中的腐蚀行为及腐蚀形貌。利用SEM、电化学阻抗谱（EIS）以及盐雾测试等方法,研究了纳米植酸锌在环氧涂层中的分散性及其对环氧涂层防腐蚀性能的影响。结果 SEM和TEM显示合成的植酸锌为球形颗粒,颗粒直径较为均匀,为20～40 nm。开路电位、极化曲线测试显示,纳米植酸锌浸出物可以抑制Q235在1%NaCl溶液中的腐蚀。XPS显示,Q235试样表面明显吸附植酸根成膜。纳米植酸锌在环氧树脂中的分散状态良好,无明显团聚现象。EIS和盐雾测试显示,纳米植酸锌可以增强环氧涂层的防护性能。结论 纳米植酸锌可以用作防锈颜料,且相比于磷酸锌防锈颜料,添加相同量的纳米植酸锌的涂层的防腐效果更佳,其可能和植酸锌的小尺寸、良...     

Passivity of Nickel electrodes in presence of the inhibitor PAB

The passivity of nickel electrodes is investigated at high potentials in absence and presence of the inhibitor 2-pentyl-aminobenzimidazole (PAB). At high potentials, the electrode is covered by a thick film of NiOOH. Various states of the 3-valent oxide film can be distinguished: Without inhibitor (3o), with an outer layer of inhibitor (3out), with an almost constant concentration profile in the total film (3tot) and a concentration gradient of inhibitor in the film caused by diffusion (3diff). Under steady state conditions, the films 3o, 3out and 3tot can be distinguished by the rate of anodic oxygen evolution, and the electrode capacity. Moreover, the reduction and reoxidation capacity of the electrode decreases from 3o to 3out and 3tot. If the film 3o is reduced and reoxidized in presence of PAB, the redox capacity decreases simultaneously with the electrode capacity due to the formation of 3diff. The role of the inhibitor is due to the formation of a thick polymer film on top of the oxide as well as to the formation of a nickel hydroxide/PAB complex. The outer polymer film has a good proton conductivity and presumably a good electron conductivity. It is concluded that the anodic oxygen evolution takes place at the inner boundary between the oxide and PAB film. The inhibition of local corrosion is probably due to formation of the outer polymer film. XPS measurements verify the expected concentration profiles of PAB in the oxide and on top of it. The PAB-film contains a lot of water, and within the passive film PAB causes a substitution of O^2? by OH^?.     

PEDOT:PSS films—Effect of organic solvent additives and annealing on the film conductivity

We report results on conductivity of PEDOT:PSS films, which contain different amounts of organic solvents, i.e., dimethyl sulphoxide (DMSO) or ethylene glycol (EG), and annealed at different temperatures. The maximum of conductivity of the resulting films was reached at about 5wt.% of DMSO or EG in the solution. At the same time, the presence of the solvent residue in the film also resulted in the poor control of the film morphology and conductivity. It was found that conductivity of a film prepared with the same DMSO content is sensitive to the surface quality of the substrate used. It was also found that annealing substantially reduces conductivity of the films prepared with and without the additives. The higher the temperature of annealing, the smaller film conductivity was observed. Correlation in changes of the electronic absorption of the PEDOT:PSS film in the near-IR and the film conductivity induced by the solvent additive was also found. Exposure of PEDOT:PSS films to the solvent vapors has been employed as an alternative controlled method to increase film conductivity. This method, in combination with quartz microbalance measurements, showed a great capability of the film to absorb DMSO vapors and that a saturation limit for conductivity is reachable after more than 20 h of exposure. Swelling and interconnection of the polymer chains is suggested to be the main factor responsible for the conductivity increase.     

Corrosion properties of thermally annealed and co-sputtered nickel silicide thin films

The corrosion properties of nickel silicide thin films are addressed by means of polarisation experiments in combination with X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) characterisation before and after the polarisation runs. The thin films studied included two pairs of nickel silicide of different compositions fabricated on Si wafer by means of ion-beam sputter deposition technique. For one pair, thin films were prepared by co-sputtering Si and Ni targets. To achieve higher crystallinity, the other pair was prepared by Ni sputter deposition followed by subsequent thermal annealing at 280 °C and 480 °C to develop single silicide phase of Ni₂Si and NiSi in individual film, respectively. The variation of the binding energy (BE) of Ni 2p_3/2 core-level peak in the XPS measurement in accordance with the Si content for this binary system follows a Boltzmann's relationship. The electrochemical polarisation tests conducted in 1.00 M HCl solution showed almost the same behaviour for the tested specimens irrespective of structure or film composition, still, the SEM and XPS studies together with optical microscopy showed that the Ni₂Si, leaner in Si, experienced thin film corrosion, whilst the NiSi appeared to be more resistant. Clearly, composition is found to be a more important design factor to tailor the corrosion properties than the structure for this binary silicide system.     

电镀Al-Mn合金及后续阳极氧化对镁合金防护性能的影响

为提高镁合金的耐腐蚀性能,采用无机熔盐电镀技术在镁合金表面电镀铝锰合金,其后在草酸溶液中对铝锰合金镀层进行阳极氧化处理,以制备耐蚀性优良的阳极氧化膜。采用扫描电镜(SEM)、X射线衍射(XRD)、X射线光电子能谱(XPS)等对阳极氧化膜的微结构进行表征,采用电化学测试方法对阳极氧化膜的耐腐蚀性能进行评价。结果表明,Al-Mn合金镀层在草酸溶液中形成的阳极氧化膜主要由稳态的α-Al2O3和亚稳态的γ-Al2O3所组成,并含有少量的MnO2及Al(MnO4)3,该阳极氧化膜具有很强的绝缘特性,其腐蚀电流密度较Al-Mn合金镀层下降了约3个数量级,较基体镁合金下降了约6个数量级,极大地提高了镁合金的耐腐蚀性。     

Preparation and electrocatalytic property of Au-Pt/SnO2/GC composite electrode

Au-Pt/SnO2/GC composite electrode was prepared by self-assembling Au-Pt nanoparticles on SnO2 film, which was deposited on actived glassy carbon (GC). Atomic force microscopy (AFM) and scanning electron microscopy (SEM) images revealed that dense and uniform Au-Pt particles with 25-nm diameter were dispersed on SnO2 film. X-ray photoelectron spectroscopy (XPS) results proved that there was an interaction between Au-Pt nanoparticles and SnO2 support. Electrochemical experiments showed that Au-Pt/SnO2/GC composite electrode had a good electrocatalytic activity to the oxidation of methanol.     

A comparative study of molybdate/silane composite films on galvanized steel with different treatment processes

Two types of molybdate/silane composite films were obtained on the surface of hot-dip galvanized steel sheets by either directly immersing in a solution containing silane and molybdate as additive (single-step process), or firstly immersing in a molybdate solution, then in a silane solution (two-step process). The chemical compositions and microstructures of the films were examined by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), Auger electron spectroscopy (AES) and reflection absorption infrared spectroscopy (RAIR). The corrosion resistances were investigated by electrochemical measurements and neutral salt spray (NSS) test. The results showed that the molybdate/silane composite film formed in the single-step process had a similar double-layer structure as that obtained in the two-step process. The inner layer was composed mainly of the elements O, Mo, Zn, and P, similar to the single molybdate film; whereas the outer layer was composed mainly of the elements C, O and Si, similar to the single silane film. Compared with the single molybdate or silane film, the corrosion current of the composite films was reduced and the impedance of the films was increased. Accordingly, the corrosion resistance of the composite films was remarkably enhanced to a level which was comparable to or even surpassing that of the conventional chromate passivation film.     

Cu-Al-Mg合金表面氧化膜分析

利用俄歇能谱、Ｘ射线电子能谱和扫描电镜对Ｃｕ－Ａｌ－Ｍｇ合金表面氧化膜进行了分析。结果表明：氧化膜的ＭｇＯ和Ａｌ２Ｏ３组成;没有进行过氧化处理的样品膜内的Ａｌ和Ｏ含量高于过氧化处理的样品,而Ｍｇ则相反;Ａｌ２Ｏ３的键合能Ｅ２ｐ３／２值大于ＭｇＯ的Ｅ２Ｐ３／２值,表明Ａｌ２Ｏ３不易被分解;进行电子轰击后,膜内Ｍｇ含量减少,ＭｇＯ被部分分解,而Ａｌ则增加,由ＭｇＯ和Ａｌ２Ｏ３组成的复合型氧化膜使得合金