NaCl溶液中氯离子浓度对铝合金电偶腐蚀的影响

测定了铝合金与Ａ３钢在含不同ＮａＣｌ溶液中偶合时的电偶电流，电位，铝合金阳极的极化电阻，表面比电阻和孔蚀电位。研究了Ｃｌ＾－浓度对阳极溶解行为的影响。结果表明，在一个临界Ｃｌ＾－浓度区域内，浓度增大，电偶电流变化很小，极化电阻，表面比电阻和孔蚀电位的变化也较小；Ｃｌ＾－浓度低于或高于临界区时，随浓度增大，电偶电流增大，极化电阻和表面比电阻减小，孔蚀电位变负。     

气相反应法合成超细粉末过程中的r~＊叶和晶型的研究

本文以ＳｉＣｌ４－ＮＨ３、ＳｉＣｌ４－Ｏ２、ＳｉＣｌ４－Ｎ２－Ｈ２、ＴｉＣｌ４－ＮＨ３－Ｈ２、ＴｉＣｌ４－Ｎ２－Ｈ２、ＴｉＣｌ４－Ｏ２、ＡｌＣｌ３－Ｏ２等为体系，运用均匀成核理论，研究了平衡常数Ｋｐ、过饱和比Ｓ及临界核半径，ｒ＊等因素对气相反应法中超细粉末的形成及粉末结构状态的影响．结果表明，当２ｒ＊大于某物质的晶格常数时，用气相反应法得到的该物质的超细粉末一般为晶体粉末，反之则得到无定形粉末．     

三元体系Na2CO3—K2CO3—H2O298K相关系和溶液物化性质的研究

用等温溶解平衡法研究了三元体系Ｎａ２ＣＯ３－Ｋ２ＣＯ３－Ｈ２Ｏ２９８Ｋ时的相平衡关系和平衡溶液的物化性质。该三元体系为复杂三元体系,形成了一种新的复盐Ｎａ２ＣＯ３．Ｋ２ＣＯ３．Ｈ２Ｏ。用经验公式对平衡液相的密度、折光率进行了计算,计算值与实测值吻合得较好。     

NaCl溶液中Zn－Al－Cd合金的接触腐蚀研究

研究了作为牺牲阳极材料的Ｚｎ－Ａｌ－Ｃｄ合金在ＮａＣｌ溶液中与Ａ３钢、３０２不锈钢和纯铜偶接时的接触腐蚀行为，探讨了溶液中Ｃｌ－浓度变化，以及电偶对中阴极金属材料和阴阳极面积比Ａｃ／Ａａ不同时对电偶电流密度ｊＺｎｇ和电偶电势Ｅｇ的影响。结果表明，电偶对中阴极金属材料不同，ｊＺｎｇ随Ｃｌ－浓度增大有不同的变化趋势；ｊＺｎｇ与Ａｃ／Ａａ成正比关系；Ｃｌ－浓度变化对Ｅｇ的影响较大，而大多数浓度下阴极金属材料和阴阳极面积比不同对Ｅｇ的影响较小     

新型L—乳酸盐酶电极的研制

本文研制一种新型乳酸盐酶生物传感器，此传感器以复合酶ＮＡＤ＾＋与ＬＤＨ共固定在经ＣＮＢｒ活化的琼脂糖上作为敏感膜。用厚为０．３ｍｍ的粒状琼脂糖制成的敏感膜电极，其响应性能最佳。此乳酸盐酶电极测试的最优条件是：在ｐＨ８．５的Ｔｒｉｓ－ＨＣｌ缓冲液中进行，温度２５℃，此缓冲液中含１．５ｍｍｏｌ·Ｌ＾－１ＶＫ３电子介体。此电极的线性反应范围为０．０４￣２．１μｍｏｌ·Ｌ＾－１，每μｍｏｌ·Ｌ＾－１乳酸盐     

钢铁表面高温氧化皮对基体钢腐蚀的影响

用静态挂片法，分别研究了表面有、无氧化皮的Ｊ－５５钢试片在３％ＮａＣｌ溶液和含Ｃａ＾２＋、Ｍｇ＾２＋、ＳＯ４＾２－、ＨＣＯ３＾－的３％ＮａＣｌ溶液中的腐蚀。表面无氧化皮试片均呈全面腐蚀，而表面有氧化皮试片均呈局部腐蚀。氧化皮的电位比基体电位正、氧化皮本身的不连续性是引起局部腐蚀的主要原因。     

PS—SbCl3／AlCl3引发α—蒎烯阳离子聚合反应

用聚苯乙烯负载ＳｂＣｌ３得到大分子催化剂ＰＳ－ＳｂＣｌ３，研究了ＰＳ－ＳｂＣｌ３／ＡｌＣｌ３复合体系对α－蒎烯阳离子聚合的催化性能。结果表明，与直接用ＳｂＣｌ３与ＡｌＣｌ３复合相比，ＰＳ－ＳｂＣｌ３／ＡｌＣｌ３体系催化α－蒎烯配合，在保持较高单体转化率的同时，使聚合反应变缓，避免了由于反应过快而引起的聚合产物中二聚体含量上升，Ｍｎ下降的现象。     

共聚物电解质MA—Na2／AA—Na水溶液的粘度特性

对共聚物电解质ＭＡ－Ｎａ２（顺丁烯二酸钠）／ＡＡ－Ｎａ（丙烯酸钠）水溶液ηｓｐ／Ｃ（比浓粘度）与浓度的关系、中性盐及溶液ｐＨ对ηｓｐ／Ｃ的影响进行了研究。结果表明，稀释ＭＡ－Ｎａ２／ＡＡ－Ｎａ溶液时，ηｓｐ／Ｃ急剧上升，而稀释含中性盐（ＫＣｌ或ＣａＣｌ２）的ＭＡ－Ｎａ２／ＡＡ－Ｎａ溶液体系时（中性盐含量保持０．０１ｍｏｌ／Ｌ），ηｓｐ／Ｃ的变化却不大。添加极少量（〈０．０５％）中性盐，可使ＭＡ－Ｎ     

溶胶－凝胶法制备薄膜湿敏元件的研究

用溶胶－凝胶法制备了Ｒ２Ｏ－Ａｌ２Ｏ３－ＳｉＯ２系（Ｒ＝Ｌｉ，Ｎａ，Ｋ）薄膜湿敏元件，研究了它们的感湿特性，对薄膜的结构、导电机理进行了讨论．获得的湿敏元件具有响应快、滞后小和灵敏度高等优点．     

溶胶—凝胶法制备薄膜湿敏元件的研究

用溶胶－凝胶法制备了Ｒ２Ｏ－Ａｌ２Ｏ３－ＳｉＯ２系（Ｒ＝Ｌｉ，Ｎａ，Ｋ）薄膜湿敏元件，研究了它们的感湿特性，对薄膜的结构、导电机理进行了讨论，获得的湿敏元件具有响应快、滞后小和灵敏度等优点。     

Application of N- and B-doped CVD diamond layers for cyclic voltammetry measurements

Conductive polycrystalline diamond layers prepared by the CVD process have received attention from electrochemists owing to such superior electrochemical properties as the wide potential window, the very low background current, the stability of chemical and physical properties.In this paper, the cyclic voltammetry application using N- and B-doped diamond electrodes was studied. Diamond layers, doped with boron and nitrogen, were synthesized on a silicon substrate in a hot-filament CVD reactor. The obtained diamond layers were characterized using Raman spectroscopy and scanning electron microscopy (SEM).The electrochemical properties of diamond layers were measured in KCl and NaCl basic solutions to gain knowledge about their potential application as an electrode material.It was found that boron doped diamond electrodes showed potential windows up to about 7 V which were almost twice wider than those observed for conventional Pt electrodes.     

Application of N- and B-doped CVD diamond layers for cyclic voltammetry measurements

Conductive polycrystalline diamond layers prepared by the CVD process have received attention from electrochemists owing to such superior electrochemical properties as the wide potential window, the very low background current, the stability of chemical and physical properties.In this paper, the cyclic voltammetry application using N- and B-doped diamond electrodes was studied. Diamond layers, doped with boron and nitrogen, were synthesized on a silicon substrate in a hot-filament CVD reactor. The obtained diamond layers were characterized using Raman spectroscopy and scanning electron microscopy (SEM).The electrochemical properties of diamond layers were measured in KCl and NaCl basic solutions to gain knowledge about their potential application as an electrode material.It was found that boron doped diamond electrodes showed potential windows up to about 7 V which were almost twice wider than those observed for conventional Pt electrodes.     

Electrochemical studies of nano-structured diamond thin-film electrodes grown by microwave plasma CVD

In this paper, we report the investigation of the electrochemical properties of nano-structured diamond thin-film electrodes on porous silicon (PSi) synthesized by microwave plasma chemical vapor deposition (MPCVD). For the application, boron-doped and undoped diamond thin film has been performed and fabricated into an electrode device, and its microstructure, electrical and chemical properties have been studied. In order to enlarge the surface area of diamond electrodes, a negative bias was applied to the MPCVD process to deposit diamond thin film in a nano-structured form, so that its surface remained rough and nano-fine structured. Diamond thin films were analyzed by Raman spectroscopy and SEM. The morphology of boron-doped diamond thin films on PSi reveals nano-rods in the shape of diamond crystallites. Their electrochemical properties were evaluated by performing cyclic voltammetry (CV) measurement in inorganic K₄[Fe(CN)₆] in a K₂HPO₄ buffer solution. Boron-doped diamond thin film on PSi has demonstrated good electrochemical properties, with a larger redoxidation current of CV, due to its rough surface, which provides a more active electrochemical interface.     

Enhanced Signal-to-Background Ratios in Voltammetric Measurements Made at Diamond Thin-Film Electrochemical Interfaces

Large signal-to-background (S/B) ratios for the Fe(CN)(6)(3)(-)(/4)(-) and IrCl(6)(2)(-)(/3)(-) redox couples in KCl have been observed in cyclic voltammetric measurements made at a conductive diamond thin-film electrode without any conventional surface pretreatment. The S/B ratios were a factor of ～16 and 8 larger at diamond than at freshly polished glassy carbon (GC) for Fe(CN)(6)(3)(-)(/4)(-) and IrCl(6)(2)(-)(/3)(-), respectively. The polycrystalline diamond film, grown on a p-Si(100) substrate, possessed significant cubic {100} faceting, as evidenced by AFM images, and was of high quality, as indicated by Raman spectroscopy. The high degree of electrochemical activity without surface pretreatment, the enhanced S/B ratios, and the excellent response stability demonstrate that diamond might be an attractive new electrode material for electroanalysis.     

Optically transparent diamond electrode for use in ir transmission spectroelectrochemical measurements

A new analytical spectroelectrochemical methodology is reported on that utilizes an optically transparent boron-doped diamond thin film. The film was deposited on undoped Si by microwave-assisted chemical vapor deposition using a 4-h growth with a 0.5% CH4/H2 source gas mixture and 2 ppm B2H6 added for boron doping. The thin-film electrode possessed a transparency of 40-60% in the mid- and far-IR regions of the electromagnetic spectrum. The physical, electrical, optical, and electrochemical properties of the electrode were characterized by scanning electron microscopy, Raman spectroscopy, X-ray diffraction, four-point probe electrical resistance measurements, IR spectroscopy, and cyclic voltammetry. The film's electrochemical behavior was evaluated using both aqueous (Fe(CN)(6)3-/4-, methyl viologen, Ru(NH3)(6)3+/2+, and IrCl(6)2-/3-) and nonaqueous (ferrocene) redox systems. The film exhibited a low and stable background current and a nearly reversible voltammetric response for all these redox systems. The diamond/Si optically transparent electrode (OTE) and a thin-layer transmission cell were used to record the spectroelectrochemical response for 10 mM Fe(CN)(6)3-/4- in 1 M KCl. Difference IR spectra (oxidized minus reduced), recorded at various applied potentials, showed that the CN vibrational mode at 2039 cm-1 for Fe(CN)(6)4- reversibly shifted to 2116 cm-1 upon oxidation to Fe(CN)(6)3-, as expected. Difference IR spectra (oxidized minus reduced) were also recorded for 20 mM ferrocene in 0.1 M TBABF4/CH3CN. A shift of the C-H bending mode of the cyclopentadienyl ring from 823 to 857 cm-1 occurred upon oxidation of ferrocene to ferricenium. The key finding from the work is that the diamond OTE provides sensitive, reproducible, and stable spectroelectrochemical responses for aqueous and nonaqueous redox systems in the mid- and far-IR.     

Morphological and electrochemical properties of boron-doped diamond films on carbon cloths with enhanced surface area

The electrochemical properties of doped diamond electrodes (10¹⁷–10¹⁹ B cm^− 3) grown on carbon fiber cloths in H₂SO₄ 0.1 mol L^− 1 electrolyte were investigated. Cyclic voltammograms of B-doped diamond/carbon fiber cloth and carbon fiber cloth electrodes showed that both kinds of electrodes possess similar working potential windows of about 2.0 V. The electrode capacitance was determined by impedance spectroscopy and chronopotentiometry measurements and very close values were obtained. The capacitance values of the diamond film on carbon fiber cloths were 180 times higher than the ones of diamond films on Si. In this paper we have also discussed the capacitance frequency dependence of diamond/carbon cloth electrodes.     

Electrochemical performance of diamond thin-film electrodes from different commercial sources

The electrochemical properties of two commercial (Condias, Sumitomo) boron-doped diamond thin-film electrodes were compared with those of two types of boron-doped diamond thin film deposited in our laboratory (microcrystalline, nanocrystalline). Scanning electron microscopy and Raman spectroscopy were used to characterize the electrode morphology and microstructure, respectively. Cyclic voltammetry was used to study the electrochemical response, with five different redox systems serving as probes (Fe(CN)(6)(3)(-)(/4)(-), Ru(NH(3))(6)(3+/)(2+), IrCl(6)(2)(-)(/3)(-), 4-methylcatechol, Fe(3+/2+)). The response for the different systems was quite reproducibile from electrode type to type and from film to film for electrodes of the same type. For all five redox systems, the forward reaction peak current varied linearly with the scan rate(1/2) (nu), indicative of electrode reaction kinetics controlled by mass transport (semi-infinite linear diffusion) of the reactant. Apparent heterogeneous electron-transfer rate constants, k degrees (app), for all five redox systems were determined from deltaE(p)-nu experimental data, according to the method described by Nicholson (Nicholson, R. S. Anal. Chem. 1965, 37, 1351.). The rate constants were also verified through digital simulation (DigiSim 3.03) of the voltammetric i-E curves at different scan rates. Good fits between the experimental and simulated voltammograms were found for scan rates up to 50 V/s. k degrees (app) values of 0.05-0.5 cm/s were observed for Fe(CN)(6)(3)(-)(/4)(-), Ru(NH(3))(6)(3+/2+), and IrCl(6)(2)(-)(/3)(-) without any extensive electrode pretreatment (e.g., polishing). Lower k degrees (app) values of 10(-)(4)-10(-)(6) cm/s were found for 4-methylcatechol and Fe(3+/2+). The voltammetric responses for Fe(CN)(6)(3)(-)(/4)(-) and Ru(NH(3))(6)(3+/2+) were also examined at all four electrode types at two different solution pH (1.90, 7.35). Since the hydrogen-terminated diamond surfaces contain few, if any, ionizable carbon-oxygen functionalities (e.g., carboxylic acid, pK(a) approximately 4.5), the deltaE(p), i(p)(ox), and i(p)(red) values for the two systems were, for the most part, unaffected by the solution pH. This is in contrast to the typical behavior of oxygenated, sp(2) carbon electrodes, such as glassy carbon.     

Surface nanostructuring of boron-doped diamond films and their electrochemical performance

Uniform and vertically aligned nanocone and nanopillar arrays were successfully constructed on heavily boron-doped nanocrysatlline diamond films by carrying out bias-assisted reactive ion etching in hydrogen/argon plasmas. The electrochemical properties of the nanostructured boron-doped diamond films were investigated by cyclic voltammetry using 1 mM [Fe(CN)6](3-/4-) as redox couple. Compared to the planar boron-doped nanocrystalline diamond film electrode, the surface nanostructuring of boron-doped diamond film electrodes demonstrate enhanced sensitivity due to their enlarged electro-active surface areas. The results indicated that boron-doped diamond nanocones and nanopillars are promising electrode materials which benefit to improve the efficiency, sensitivity and reproducibility of biomedical and chemical sensors.     

Equilibrium and kinetic behavior of Fe(CN)6(3-/4-) and cytochrome c in direct electrochemistry using a film electrode thin-layer transmission cell

We report on the design and performance of a thin-layer electrochemical cell optimized for use with optically transparent film electrodes in combination with UV/vis and IR transmission spectroscopic measurements. The cell allows for measurements under both aerobic and anaerobic conditions. The direct, unmediated electron transfer, as assessed by the current transient, and the corresponding optical response observed for the Fe(CN)(6)(3-/4-) couple were in good agreement with theoretical predictions for voltammetry and optical absorption by an analyte confined in a thin layer. Chronoamperometric and spectroscopic measurements of Fe(CN)(6)(3-/4-) on gold mesh electrode revealed fast kinetics strongly influenced by the electrolyte concentration. Maximal apparent rates exceeding 2 s(-1) in 1 M KCl were observed optically. The direct kinetic and thermodynamic behavior of cytochrome c was compared with several electrode materials using the cell. The results showed heme ligand-dependent changes in the protein-electrode interactions. Mid-UV/visible spectral changes upon redox transitions in native cytochrome c and its cyanide derivative, as well as dissociation of the ferrous cytochrome c-CN complex, are reported.     

Optical and electrochemical properties of optically transparent,boron-doped diamond thin films deposited on quartz

The optical and electrochemical properties of transparent, boron-doped diamond thin film, deposited on quartz, are discussed. The films were deposited by microwave-assisted chemical vapor deposition, for 1-2 h, using a 0.5% CH4/H2 source gas mixture at 45 Torr and 600 W of power. A high rate of diamond nucleation was achieved by mechanically scratching the quartz. This pretreatment leads to the formation of a continuous film, in a short period of time, which consists of nanometer-sized grains of diamond. The thin-film electrode was characterized by cyclic voltammetry, atomic force microscopy, and UV-visible absorption spectrophotometry. The film's electrochemical response was evaluated using Ru(NH3)6(3+/2+) in 1 M KCl, Fe(CN)6(3-/4-) in 1 M KCl, and chlorpromazine (CPZ) in 10 mM HClO4. The film exhibited a low voltammetric background current and a stable and active voltammetric response for all three redox systems. The optical transparency of the polycrystalline film in the visible region was near 50% and fairly constant between 300 and 800 nm. The optical and electrical properties were extremely stable during 48-h exposure tests in various aqueous (HNO3, NaOH) solutions and nonaqueous (e.g., chlorinated) solvents. The properties were also extremely stable during anodic and cathodic potential cycling in harsh aqueous environments. This stability is in stark contrast to what was observed for an indium-doped tin oxide thin film coated on quartz. The spectroelectrochemical response (transmission mode) for CPZ was studied in detail, using a thin-layer spectroelectrochemical cell. Thin-layer voltammetry, potential step/ absorption measurements, and detection analytical figures of merit are presented. The results demonstrate that durable, stable, and optically transparent diamond thin films, with low electrical resistivity (approximately 0.026 omega x cm) laterally through the film, can be deposited on quartz.