Characteristics and self-cleaning effect of the transparent super-hydrophobic film having nanofibers array structures

Transparent super-hydrophobic films were fabricated using the PDMS method and silane process, based on anodization in phosphoric acid. Contact angle tests were performed to determine the contact angle of each film according to the anodizing time. Transmittance tests also were performed to obtain the transparency of each TPT (trimethylolpropane propoxylate triacrylate) replica film according to the anodizing time. The contact angle was determined by studying the drop shape, and the transmittance was measured using a UV-spectrometer. The contact angle increases with increasing anodizing time, because increasing pillar length can trap more air between the TPT replica film and a drop of water. The transmittance falls with increasing anodizing time because the increasing pillar length causes a scattering effect. This study shows that the pillar length and transparency are inversely proportional. The TPT replica film having nanofibers array structures was better than other films in aspect of self-cleaning by doing quantitative experimentation.     

阳极吸附伏安法测定盐酸莫西沙星

提出了阳极吸附伏安法测定盐酸莫西沙星的方法。在pH 6.55的B-R缓冲溶液中,开路富集120s后,盐酸莫西沙星在碳糊电极表面于0.987V(vs.SCE)处产生一灵敏的氧化峰,该氧化峰电流与盐酸莫西沙星浓度在5.6×10-7～1.0×10-5 mol.L-1范围内呈线性关系,其检出限(3s/k)为4.3×10-8 mol.L-1。方法用于模拟片剂样品中盐酸莫西沙星的测定,测定值与标示值相符,其相对标准偏差(n=6)为3.8%,以健康人尿液为基体做加标回收试验,测得平均回收率为101.6%。     

Synthesis of niobium oxide nanopowders by field-crystallization-assisted anodization

Herein, for the first time, we demonstrate that a large quantity of niobium oxide nanopowders consisting of amorphous round shape nanoparticles and highly crystalline needle shape nanoparticles can be prepared by anodization of a niobium foil in ethylene glycol containing NH₄F at a high voltage. FE-SEM, TEM, XRD measurements were performed to characterize the anodically prepared nanopowders and to reveal the formation mechanism. We ascribed the formation of niobium oxide nanopowders on the foil to field-crystallization induced breakdown of oxide film and chemical dissolution.     

Determination of trace aluminium by adsorptive stripping voltammetry on a preplated bismuth-film electrode in the presence of cupferron

This work reports the use of adsorptive stripping voltammetry (AdSV) for the determination of aluminium on a rotating-disc bismuth-film electrode (BiFE). Al(III) ions in the non-deoxygenated sample were complexed with cupferron and the complex was accumulated by adsorption on the surface of the preplated BiFE. The stripping step was carried out by using a square-wave (SW) potential-time voltammetric excitation signal. The experimental variables as well as potential interferences were investigated and the figures of merit of the method were established. Using the selected conditions, the 3σ limit of detection for aluminium was 0.5 μg l⁻¹ at a preconcentration time of 240 s and the relative standard deviation was 4.2% at the 5 μg 1⁻¹ level for a preconcentration time of 120 s (n = 8). The accuracy of the method was established by analysing water and metallurgical samples.     

微分脉冲溶出伏安法测定2,4-二硝基-1-萘酚

以Britton-Robinson(pH=8.0)缓冲液为底液,富集电位为-0.05V,富集时间为30s,电位扫描速率20mV/s,产生2个完全分离的峰,在-0.58±0.01V(vs.Ag/AgCl)处产生的峰灵敏度高且峰形好,故以此峰为定量峰。2,4_二硝基_1_萘酚浓度在6.00×10-8～2.00×10-6mol/L时与峰电流呈良好的线性关系,线性相关系数为0.9996。检出限为4.00×10-9mol/L,信噪比S/N约为10。     

Direct determination of selenium in whole blood by anodic stripping voltammetry

Trace quantities of selenium can be determined in the presence of iron, copper and lead using anodic stripping voltammetry, depositing at –0.60 V in 0.1M HClO₄ and stripping in the anodic direction. Two separate peaks are observed at –0.25 V and –0.10 V belonging to copper and selenium, respectively. Sometimes one peak may be observed for both copper and selenium. In this case one more stripping (without deposition) must be done to obtain separate peaks. After standard addition, two strippings have to be done also. With this proposed method, 10^–7 M selenium could be determined as (1.09±0.03) × 10^–7 M with a 90% confidence interval in blood samples without any separation.Presented at Xth National Chemistry Congress, Bursa, Turkey, September 19–21, 1994     

Nafion修饰金电极阳极溶出伏安法测定痕量碲

本文用Ｎａｆｉｏｎ修饰金盘电极，在０．０４ｍｏｌ／ＬＬｉＣｌ和ＰＨ２的Ｈ２ＳＯ４底液中，阳极溶出伏安法测定痕量碲，研究了富集溶出过程的特性和优化条件，碲浓度在０．２－１５ｎｇ／ｍＬ范围内与溶出峰电流呈良好的线性关系。本法灵敏度高，选择性好，用于测定小麦粉和玉米粉中痕量碲，测定标准偏差小于０．０７μｇ／ｇ，与ＩＣＰ测定结果比较其相对误差小于１６％。     

锑(Ⅲ)-棓酸配合物示差脉冲吸附溶出伏安法研究

本文在前文的基础上,进一步研究了锑(Ⅲ)-棓酸配合物在醋酸盐缓冲溶液中的示差脉冲吸附伏安特性,探讨了反应机理,用拟定的方法测定了铜合金中的痕量锑,结果满意。     

A green and efficient access to awl nitriles via an electrochemicalanodic oxidation

The nitrile functionality is a key building block in synthetic chemistry, and has wide applications in pharmaceuticals. However, traditional methodologies for the synthesis of nitriles are limited to harsh reaction conditions. Herein, we report a new and efficient access to aryl nitriles by an electrochemical synthesis. Compared with the conventional synthetic methods, this electrochemical synthesis is more environmentally friendly and easier to handle.     

Metal ion analysis in contaminated water samples using anodic stripping voltammetry and a nanocrystalline diamond thin-film electrode

Boron-doped nanocrystalline diamond thin-film electrodes were employed for the detection and quantification of Ag (I), Cu (II), Pb (II), Cd (II), and Zn (II) in several contaminated water samples using anodic stripping voltammetric (ASV). Diamond is an alternate electrode that possesses many of the same attributes as Hg and, therefore, appears to be a viable material for this electroanalytical measurement. The nanocrystalline form has been found to perform slightly better than the more conventional microcrystalline form of diamond in this application. Differential pulse voltammetry (DPASV) was used to detect these metal ions in lake water, well water, tap water, wastewater treatment sludge, and soil. The electrochemical results were compared with data from inductively coupled plasma mass spectrometric (ICP-MS) and or atomic absorption spectrometric (AAS) measurements of the same samples. Diamond is shown to function well in this electroanalytical application, providing a wide linear dynamic range, a low limit of quantitation, excellent response precision, and good response accuracy. For the analysis of Pb (II), bare diamond provided a response nearly identical to that obtained with a Hg-coated glassy carbon electrode.