中性红聚合膜的电化学表征及性质

在中性溶液中用重复电位扫描法在玻碳电极上制备了中性红聚合膜.中性红的聚合是在高电位引发下,氧化中性红产生自由基发生链式引发聚合.用铁氰化钾作为探针采用循环伏安法和电化学扫描电镜表征了不同聚合圈数的电极的表面性质.随着扫描圈数的增加,聚合膜的厚度也增加,同时电极由导体向绝缘体转变.电极表面的形貌图也说明了这一现象.     

亚甲基兰中性红聚合膜电极对多巴胺的分析测定

在中性溶液中用重复电位扫描法在玻碳电极上制备了亚甲基兰混合中性红聚合膜。其聚合是在高电位引发下,氧化中性红和亚甲基兰产生自由基发生链式引发聚合时该聚合物修饰电极在pH值为8．4时对多巴胺有良好的催化氧化能力,在3×10^-6～3×10^-4mol／L范围与峰电流成线性关系。可用于多巴胺的测定。     

聚吡咯薄膜修饰电极的制备

在裸玻碳电极上用恒电位法聚合吡咯，改变聚合条件，如聚合电位，聚合时间，扫描速度，制备PPy膜电极。     

基于聚苯胺-壳聚糖复合膜的葡萄糖电化学生物传感器的制备

在玻碳电极表面通过循环伏安法的电聚合修饰聚苯胺膜,再利用壳聚糖将葡萄糖氧化酶(GOD)固定于修饰电极表面,制成新型的葡萄糖传感器;通过循环伏安法、交流阻抗技术和计时电流法考察了电极的电化学特性;考察了壳聚糖用量和电聚合圈数对修饰电极的影响;采用电流-时间法考察了该传感器对葡萄糖的电化学响应特性。结果表明,该传感器对葡萄糖的响应速度为3.5s。在优化的实验条件下,该传感器在葡萄糖浓度为9.6×10-8~5.12×10-7mol/L、5.12×10-7~1.12×10-6mol/L范围内有线性响应,检测限为3.3×10-8mol/L。样品测定的加标回收率为96.1%~101.5%。此外该传感器具有响应快、稳定性好和选择性好的特点。     

碳纳米管/纳米TiO2-聚苯胺复合膜电极的电化学制备

在含有0.2 mol.L-1苯胺的0.5mol.L-1H2SO4溶液中,采用循环伏安法(CV),以扫描速度50mv.s-1,扫描电位为-0.1～0.9V,在碳纳米管/纳米TiO2(CNT/nanoTiO2)膜电极上实现了苯胺的电化学聚合,并通过扫描电镜对膜层的微观形貌进行观察,发现这种在纳米基体上聚合得到的聚苯胺膜呈疏松、多孔的纳米纤维网状结构,不同于在金属基体上聚合得到的颗粒状聚苯胺膜.     

血红蛋白在甲基纤维素凝胶中的电化学研究

用甲基纤维素（MC）水凝胶将血红蛋白（Hb）固定在热裂解石墨电极表面,制成了稳定的Hb-MC膜修饰电极.包埋在甲基纤维素膜中的血红蛋白可以与电极直接传递电子.在pH7.0的磷酸盐缓冲溶液中可得到一对可逆的血红蛋白辅基血红素Fe（III）/Fe（II）电对氧化还原峰,式电势为-0.312V（vs SCE）.其式电势随溶液的pH值增加而负移且成线性关系,直线斜率为-41.0mV/pH,说明电子传递过程伴随有质子的转移.     

铂微粒修饰碳纳米管-纳米TiO2/聚苯胺复合膜电极对抗坏血酸的电催化氧化

采用循环伏安法,在含有0.2mol.L-1苯胺的0.5 mol.L-1的硫酸溶液中,以50mv.s-1的扫描速度,在-0.1~0.9V范围内实现苯胺在碳纳米管-纳米TiO2膜电极上的电化学聚合,得到翠绿色的聚苯胺膜,并用交流阻抗谱对复合膜的电化学性质进行了表征。在该电极上修饰铂,制得铂微粒修饰聚苯胺复合膜电极,研究了其对抗坏血酸的电催化氧化,发现修饰后的电极对抗坏血酸的氧化有很高的催化活性。     

谷氨酸修饰玻碳电极的制备及性质研究

研究了谷氨酸在玻碳电极表面上电化学聚合的条件及修饰电极的电化学特性,发现在0.0V-1.9V范围内,以10mV的扫描速度循环扫描10圈制备Glu/GCE电极效果最好,并且Glu/GCE电极在强酸性环境中对Fe(CN)63-探针离子的阻滞行为较弱.     

谷氨酸修饰玻碳电极的制备及性质研究

研究了谷氨酸在玻碳电极表面上电化学聚合的条件及修饰电极的电化学特性,发现在0.0V-1.9V范围内,以10mV的扫描速度循环扫描10圈制备Glu/GCE电极效果最好,并且Glu/GCE电极在强酸性环境中对Fe(CN)63-探针离子的阻滞行为较弱.     

Pt/S_(ad)电极上1,2-丙二醇吸附和氧化的CV和EQCM研究

运用电化学循环伏安(CV)和电化学原位石英晶体微天平(EQCM)研究了Pt电极表面不可逆吸附S原子的电化学特性以及Pt电极上S吸附原子对0.1mol·L–1 H2SO4溶液中1,2-丙二醇电催化氧化性能的影响。研究发现,当扫描电位的上限Eu≤0.70V(SCE)时,Sad可以稳定地吸附在Pt电极表面;通过控制电位扫描上限和扫描圈数剥离部份S可方便地得到Sad的不同覆盖度;Pt电极表面S吸附原子的氧化会消耗表面氧物种,抑制了1,2-丙二醇的电氧化。从电极表面质量定量变化的角度,提供了吸附原子电催化作用的新数据。     

抗坏血酸存在下六氮杂铜配合物修饰金电极对多巴胺的分析测定

利用自组装的方法制备了一种新型六氮杂铜配合物修饰的金电极。采用循环伏安法和电化学隧道扫描显微镜对该电极进行了表征。计算了该电极电子转移系数为0.42,标准速率常数为38S^-1。该电极可以有效地催化氧化多巴胺,当抗坏血酸浓度为1-5mmol/L时,可用于多巴胺的分析测定,检测限低至1.8×10^-8mol/L。     

Pattern Analysis on DC Breakdown Phenomenon of Polyethylene Films

Low-density polyethylene ( LDPE) film andhigh-density polyethylene (HDPE) film are two typi-cal polyethylene films and widely used in electricaland electronic equipment, such as covering and corein ultra-high frequency cables[1—3]. It is well knownthat the unexpected defects in insulating polyethylenefilms under a high voltage will lead to the occurrenceof insulation degradation and act as the beginning ofinsulation breakdown. The insulation degradation ad-vances not only with the accumula…     

槲皮素在壳聚糖席夫碱衍生物修饰电极上的电化学行为研究

利用壳聚糖（CTS）与香草醛合成改性壳聚糖席夫碱衍生物（VCG）,将其滴涂在玻碳电极表面形成薄膜,通过吸附富集电子介体Fe（CN）6^3-,使其固定在电极表面,制备了壳聚糖席夫碱衍生物修饰玻碳电极（Fe（CN）6^3-3-/VCG/GC）.以此修饰电极为工作电极,铂电极为对电极,饱和甘汞电极为参比电极,用循环伏安法对槲皮素的电化学行为进行了研究.在pH 6.0的磷酸盐缓冲液（PBS）中,氧化峰电流与槲皮素浓度在10^-4～10^-2 mol/L范围内呈比较好的线形关系,可用于槲皮素测定.     

粉末微电极的制备及特征分析

粉末微电极是用一般的粉末材料填入被腐蚀了的微盘电极空腔中制得的微电极．它是多孔电极与微电极的有机结合．粉末微电极的端面具有微盘电极的直径以及表观面积,而粉层部分具有多孔电极的性质．因而,相对于平面微盘电极,粉末微电极的实际有效反应表面积显著提高．相应地,粉末微电极上氧化还原电对的表现交换电流密度以及表现可逆性显著增加．这些特征已成功地应用于化学电源、电催化以及生物电化学等领域．     

关于电极电势几个问题的讨论

从电极电势的定义出发，探讨了绝对电极电势与相对电极电势、电极电势的符号、标准电极电势、氧化电势与还原电势等有关电极电势的具体问题。     

Photo-Corrosion of CdSe Film Electrode by Electrochemical Modulation Reflectance Spectrum

The photo-corrosion of electrodeposited polycrystalline CdSe electrode was inhibited effectively by coating a thin layer of the conductive polyaniline (PAN) film. The relation between the performance and internal band structure of such film-covered PAN/CdSe electrode was studied by the electrochemical modulation reflectance spectrum (EMRS). EMRS of beth CdSe and PAN/CdSe electrodes in K4Fe(CN)6/K3Fe(CN)6 solution exhibited typical France-Keidysh oscillations, by which the values of the energy gap and flat band potential were determined. The EMRS results indicated that the energy band structure of CdSe electrode was not changed after coated with PAN film, so that the photoelectrochemical characteristic of PAN/CdSe electrode was rather similar to that of CdSe electrode.     

Electrochemical detection of hydrogen peroxide at a waxed graphite electrode modified with platinum-decorated carbon nanotubes

Platinum-decorated carbon nanotubes(CNT-Pt) were produced by the chemical reduction method. A novel modified electrode was fabricated by intercalated CNT-Pt in the surface of waxed graphite,which provided excellent electrocatalytic activity and selectivity for both oxidation and reduction of hydrogen peroxide. The current response of the modified electrode for hydrogen peroxide was very rapid and the detection limits in amperometry are 2.5×10-6 mol/L at reduction potential and 4.8×10-6 mol/L at oxidation po...     

Impedance characteristics for solid Ag/AgCl electrode used as recording electric field generated by vessels in seawater

Ag/AgCl electrode has been prepared using pressed powder techniques. In order to verify the feasibility of this type of electrode used as detecting electric field generated by vessels in seawater, its characteristics of DC resistance, low frequency AC impedance, and receiving impedance in artificial seawater have been studied by polarization measurements, low frequency electrochemical impedance spectra, the open and short circuit cell conditions. The results show that the electrode can keep a low resistance when it responses the weak electrostatic field in seawater. The AC impedance of the electrode decreases as the frequency of the signal increasing. The receiving impedance decreases when the frequency of external field increases too. The valid detection bandwidth is determined by the properties of the impedance and the reactions occurring on the surface of the electrode.