EQCM and in-situ reflectance FTIR spectroscopic studies of adsorption and oxidation of methanol on Pt electrode in alkaline media

The adsorption and oxidation of methanol on Pt electrode in alkaline media have been investigated by using cyclic voltammetry, electrochemical quartz crystal microbalance (EQCM) and in-situ reflectance FTIR spectroscopy. The experimental results demonstrated that the electrooxidation of CH3OH was closely relative to solution acidity. Only one current peak of methanol oxidation in PGPS was detected at -0.09 V, which illustrated the disappearance of the second current peak due to Pt electrode passivation in alkaline media. The magnitude of the dissociative adsorbate of methanol in alkaline media is smaller than that in acidic media. The main product, such as CO2 and CO32-, was detected clearly and the reactive intermediates that were determined by FTIRS under experimental condition might be mainly HCOO- species. The EQCM studies provide quantitative results of surface mass changes during methanol oxidation, and have thrown new light in the elucidating methanol oxidation

CLSI EP15-A3在临床生化正确度验证中的应用

目的探讨美国临床和实验室标准化协会（CLSI）EP15-A3文件在正确度验证中的应用价值。方法按照EP15-A3文件5×5实验设计方案,用IFCC提供的Rela A（水平1）和Rela B（水平2）样品、美国国家标准与技术研究院（NIST）909C参考物质分别验证肌酐（Cr）、尿素（Urea）、尿酸（UA）、总胆固醇（TC）、三酰甘油（TG）、葡萄糖（Glu）的正确度。每个样品每天1批,每批重复5次,共5 d,每个样品获得25个数据。用Grubbs’法计算离群值,单因素方差分析（ANOVA）计算用户的批内不精密度（SR）和实验室内不精密度(SWL),基于SR和SWL计算结果的均值及其标准差,计算靶值（TV）及其标准误差,最后计算出TV的确认区间（VI）,观察各指标检测均值是否在VI内,如通过则用户证明了候选方法的偏差可接受;若不通过则计算均值和TV的相对偏差,观察该相对偏差是否小于用户定义的可接受范围（<1/2 TEa）,若是则证明候选方法的偏差可接受。否则,需查找原因或与厂家联系。结果6个生化项目的测定结果均通过Grubbs’法离群值检查,各项目无离群值。该次验证实验中,除NIST 909C参考物质样品Urea、TC,Rela样品Cr水平2均值不在VI内,但相对偏差均小于1/2 TEa外,其他均值都在VI内。结论用EP15-A3文件进行验证的6个生化项目的正确度均符合临床要求。国家自然科学基金(81572088);;“十二五”国家科技支撑计划(2013BAI02B04,2012BAI37B01);;广东省中医院拔尖人才项目(2014-47);广东省中医院综合标准化示范项目(YN2015BZ10

甲基丙烯酸长链烷基酯的基团转移聚合研究

进行了甲基丙烯酸长链烷基酯（庚、辛、壬酯的混合物）的基团转移聚合．得到了具有较高分子量和转化率．分子量分布较窄的聚合产物．研究了聚合条件对产物的分子量及分布，转化率，聚合速率的影响．探讨了聚合反应动力学．认为聚合体系的非极性不利于催化剂的离解，单体较大的空间障碍使扩散困难．均是表观活化能升高和转化难以完全的原因．发现此类单体的基团转移聚合对温度的依赖性极大，本体聚合无自加速现象，容易得到较高的分子量

线材硫酸盐连续光亮镀锌添加剂的最佳配比及其电化学性能

线材硫酸盐连续镀锌工艺常用于钢丝、钢管等型材的防腐蚀处理,应用广泛,但其镀层晶粒粗糙,光亮度欠佳,存在易变色、耐蚀性能下降等缺点。通过赫尔槽试验,用正交法确定了硫酸盐镀锌液添加剂中主光亮剂苄叉丙酮、载体光亮剂、苯甲酸钠、辅助光亮剂A和扩散剂NNO的最佳配比以及最大影响因子,研究了各组分的电化学性能。结果表明:组合添加剂组成的最佳配比为2:22:8:1:6,对镀层影响最大的因子是主光亮剂+载体以及辅助光亮剂A的量,其他组分与主光亮剂、载体及辅助光亮剂A产生协同效应,也能有效地提高镀液和镀层的综合性能。优化该添加剂的复配对减低生产成本具有一定的指导作用

碱性介质中甲醇在铂电极表面吸附和氧化的电化学原位FTIR反射光谱和EQCM研究

运用电化学循环伏安、原位FTIR反射光谱和石英晶体微天平(EQCM)等方法研究了碱性介质中甲醇在Pt电极表面吸附和氧化行为.结果表明:甲醇电氧化与溶液酸碱性有密切的关系.酸性介质中甲醇在Pt电极上的CV曲线有两个正向氧化峰,而碱性介质中只有一个正向氧化峰,第二个氧化峰的消失可能是由于碱性介质中Pt电极在高电位下形成高氧化态的氧物种毒化其表面引起的.碱性介质中甲醇解离吸附产物的数量比酸性介质的明显减少,对甲醇氧化的第一个氧化峰表现出更高的电催化活性.目前实验条件下,原位FTIR反射光谱检测到:碱性介质中甲醇电氧化的最终产物是CO_2和CO_3~(2-),反应中间体主要为HCOO~-物种.从电极表面质量定量变化的角度提供了甲醇反应机理的新数据

碱性介质中正丁醇在铂电极上吸附和氧化的电化学原位FTIR反射光谱和EQCM研究

运用电化学循环伏安(CV)、原位FTIR反射光谱和电化学石英晶体微天平(EQCM)等方法研究了碱性介质中正丁醇在Pt电极表面吸附和氧化行为。结果表明:正丁醇电氧化过程与溶液酸碱性有着密切的关系。酸性介质中正丁醇在Pt电极上的CV曲线有2个正向氧化峰,而碱性介质中只有1个正向氧化峰,第2个氧化峰的消失可能是由于碱性介质中Pt电极表面钝化引起的。原位FTIR反射光谱检测到,在实验条件下,碱性介质中正丁醇电氧化过程的最终产物只有丁酸根。EQCM研究还从电极表面质量定量变化的角度提供了正丁醇反应机理的新数据

The adsorption and oxidation of isopropanol at platinum electrode in alkaline media

The adsorption and oxidation of isopropanol in alkaline media at platinum electrode have been investigated by using electrochemical quartz crystal microbalance (EQCM) and in situ FTIR spectroscopy. The results show that there is no self-poisoning in the electrooxidation of isopropanol in alkaline media. Though no poison species, such as CO, are evidenced by in situ FTIR spectroscopy, the adsorption of isopropanol or its dissociative products on Pt surface is suggested by EQCM data. The final product of isopropanol oxidation is only acetone under experimental condition, which suggests that the oxidation of isopropanol into acetone takes place via dehydrogenation step. The EQCM studies provide quantitative results of surface mass variation and have thrown new light in the elucidating isopropanol oxidation

Electrochemical Behavior of Redox Proteins on ZnO Nanorod-Modified Electrodes Prepared by Electrodeposition

We successfully prepared ZnO nanorod-modified Au (ZnO nanorod/Au) electrodes using one-step cathodic electrodeposition. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were used to characterize the morphology and crystal phase of the ZnO nanorods. The data showed that the ZnO nanorods were wurtzite type crystals with a hexagonal rod shape and a diameter of about 100 nm and that the ZnO nanorods were arranged well on the surface of electrodes. These ZnO nanorod-modified electrodes were able to detect direct electron transfer from cytochrome c (cyt c). Cyclic voltammograms showed that the direct electron transfer of cyt c with heme iron in different valence states was easily achieved by the ZnO nanorod/Au electrode. Data of amperometric responses demonstrated that a linear amperometric response to hydrogen peroxide was observed on the ZnO nanorod/Au electrodes after adsorbing cyt c.National Natural Science Foundation of China[20603027, 21021002, 20973134]; National High Technology Research and Development Program of China[2009AA03Z327

Charge transport performance of Nafion-based redox polymer in atmosphere

The charge transport performance of the Nafion-based redox polymer films prepared under different conditions was investigated by cyclic voltammetry in the sandwiched cells. The results showed that the apparent charge transfer diffusion coefficient(D-a) of the Nafion[M(bpy)(3)(2+), PEG (polyethylene glycol)] (M=Ru or Fe) films is about 10(-6)-10(-7) cm(2) . s(-1) and the mobility of the electron or hole (mu) was about 10(-4)-10(-5) cm(2) . V-1 . s(-1). In order to decrease the resistance of the interface, a polyaniline (PANI) layer was added to the interface of indium tin oxide coated conducting glass (ITO) electrode and the redox polymer. Consequentially, the D-a could be increased to about 10(-5)-10(-6) cm(2) . s(-1) and mu to about 10(-3)-10(-4) cm(2) . V-1 . s(-1), and the operating current of the cells under 600 mV bias could be increased by almost 100 times. In addition, the D-a and mu of this redox polymer film had just reduced slightly after 30 d kept in atmosphere. Therefore, the redox polymer film is sufficiently stable