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71.
Shiun-Sheng JanJung-Lung Chiang Ying-Chung Chen Jung-Chuan ChouChien-Chuan Cheng 《Analytica chimica acta》2002,469(2):205-216
The sol-gel-derived lead titanate (PbTiO3) membrane has been successfully applied as a pH sensitive layer to form the PbTiO3 gate ion-sensitive field-effect transistor (ISFET). There exhibit the excellent quasi-Nernstian response of 56-59 mV pH−1, good surface adsorption and anticorrosion characteristics via the C-V measurement of the EIS structure. At a specific pH concentration, the output and transfer characteristics are very similar to the behaviours of MOSFETs, and the ISFET model can be derived by the modified MOSFET model. As it operated in the nonsaturation region, there exhibits a linear pH response of about 56-59 mV pH−1. On the other hand, as it operated in the saturation region, the pH response and linearity can be controlled by adjusting the VGS values, e.g. the pH responses of −4.2, −24.8 and −31.3 μA pH−1 and the correlation coefficients of 0.9491, 0.9995 and 0.9996 at VGS=1, 3 and 5 V can be obtained, respectively. Besides, in order to get the best pH response and the minimized leakage current, the heat treatment temperature of the PbTiO3 membrane must be limited between 350 and 450 °C. 相似文献
72.
73.
Contributions to the Properties of Titanates with Ilmenite Structure. II. Study on the Thermodynamics and the Electrical Conductivity of NiTiO3 and Other Phases with Ilmenite Structure NiTiO3 shows a phase transition at high temperatures (Tc = 1290°C). The standard enthalpy and entrop of the reaction NiO + TiO2 = NiTiO3 was estimated for temperatures above and below the transition temperature using emf-measurements based on the following solid state galvanic cell: Ni,TiO2, NiTiO3|ZrO2(+CaO)|Ni,NiO. The transition enthalpy was found to be 18 ± 2 kJmol?1, The transition entropy is 12 ± 1 JK?1mol?1. This is in good agreement with the calculated entropy change for an order-disorder transition (11.5 JK?1mol?1). The influence of other cations like Mg2+ and Co2+ on the transition temperature was investigated by measurements of the electrical conductivity as a function of composition. Ni1?xMgxTiO3 shows a strong shift of the transition to higher temperatures if a small part of the Ni2+ was replaced by Mg2+. A linear correlation between the temperature shift and the amount of Co2+ was found for Ni1?xCoxTiO3. Thermoanalytical investigations reveal an endothermic peak during the heating period some degrees below the melting point of CoTiO3. The substitution of Ge4+ for Ti4+ is without any influence on the transition temperature. By doping the NiTiO3 with Ga2O3, the anomalous increase of the electrical conductivity with temperature is shifted to lower temperatures. 相似文献
74.
A sonochemical based green synthesis method playa powerful role in nanomaterials and composite development. In this work, we developed a perovskite type of strontium titanate via sonochemical process. SrTiO3 particles were incorporated with nitrogen doped graphene oxide through simple ultrasonic irradiation method. The SrTiO3/NGO was characterized by various analytical methods. The nanocomposite of SrTiO3/NGO was modified with laser-induced graphene electrode (LIGE). The SrTiO3/NGO/LIGE was applied for electrochemical sensor towards chemotherapeutic drug detection (nilutamide). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques have been used to examine the electrochemical performance of nilutamide (anti-cancer drug). DPV was found to be more sensitive and found to exhibit a sensitivity 8.627 µA µM−1 cm−2 for SrTiO3/NGO/LIGE with a wide linear range (0.02–892 µM) and low Limit of detection (LOD: 1.16 µM). SrTiO3/NGO/LIGE has been examined for the detection of nilutamide in blood serum and urine samples and obtained a good recovery in the range of 97.2–99.72 %. The enhanced stability and selectivity and practical application results indicates the suitability of SrTiO3/NGO/LIGE towards the detection of nilutamide drug in pharmaceutical industries. 相似文献
75.
采用静电纺丝法制备(1-x)Ni0.5Zn0.5Fe2O4-(x)Pb(Zr0.52Ti0.48)O3(简称为(1-x)NZFO-(x)PZT, x=0.1、0.2、0.3、0.4、0.5)磁电复合纳米纤维, 研究了PZT含量对复合纳米纤维结构、电磁特性及微波吸收性能的影响。所有样品均由尖晶石结构NZFO和钙钛矿结构PZT两相所组成。由于NZFO磁损耗与PZT介电损耗的协同效应及界面效应的加强, 适量PZT相的引入可改善复合纳米纤维吸波涂层的电磁阻抗匹配和衰减特性, 提高微波吸收性能。x=0.3和0.4的复合纳米纤维分别在低频和高频范围表现出最强的微波吸收能力。当涂层厚度为2.5~5.0 mm时, x=0.3样品的最小反射损耗在6.1 GHz处达-77.2 dB, 反射损耗小于-10 dB的有效吸收带宽为11.2 GHz(2.8~12.9和16.9~18 GHz);x=0.4样品的最小反射损耗位于18 GHz处为-37.6 dB, 有效吸收带宽达到12.5 GHz(3.3~12.5和14.7~18 GHz)。 相似文献
76.
Li4Ti5O12 (LTO)/carbon nanotubes (CNTs) composite material is synthesized based on a solid-state method by sand-milling, spray-drying and calcining at 850 ℃ under N2 flow. The LTO/CNTs samples with 1 wt% and 3 wt% weight ratio of CNTs addition and the pristine LTO sample are prepared. The rate performance and the thermal stability of these samples are investigated based on LiMn2O4 (LMO)/LTO full-cell. The results show that theweight ratio of CNTs addition has distinct effect on LTO performances. The composite materials of LTO composited CNTs have better performance at high-rate due to the intercalation enhancement by conductive network of CNTs. At second, the overcharging temperature response of the cell's surface with 1 wt% CNTs addition is the lowest. The particle size distribution is measured and the most uniform particles are obtained with 1 wt% CNTs addition. This trend could explain that the mediumquantity of CNTs is optimal to improve the heat and mass transfer and prevent the problems of crystallite growing interference and aggregation during the calcination process. 相似文献
77.
采用流延热压工艺制备Ba0.6Sr0.4TiO3(BST)/聚偏氟乙烯(PVDF)?聚甲基丙烯酸甲酯(PMMA)复合薄膜,研究了PMMA含量对复合材料微观组织结构和介电性能的影响规律。结果表明,BST相能够均匀分散在聚合物基体中,归因于PMMA与PVDF良好的相容性,2种聚合物之间的界面不分明;随着PMMA含量的增加,复合材料的介电常数先降低后升高,耐击穿强度和介电可调性先增加后减少。PMMA含量(体积分数)为15%的BST/PVDF?PMMA15复合材料的综合性能最佳:介电常数为23.2,介电损耗为0.07,耐击穿强度为1412 kV·cm-1,在550 kV·cm-1偏压场下,介电可调性为26.2%。 相似文献
78.
通过结合固相和液相包覆在Al掺杂LiCoO2表面共包覆了钛酸锂(Li4Ti5O12)和聚吡咯(PPy)。这种双包覆方法不仅稳定了高电压下LiCoO2的表面,还增强了材料的离子和电子电导率。电化学测试表明,当活性物质、导电剂和黏结剂的质量比为80∶ 10∶10时,在0.5C (1C=180 mA·g-1)电流下,循环300周后的容量保持率为76.9%,且在5C电流密度下可逆比容量为150 mAh· g-1;由于双包覆后LiCoO2电子电导率大幅提高,当活性物质、导电剂和黏结剂的质量比为90∶3∶7时,在0.5C电流下,循环200周后的容量保持率为82.8%,且在5C电流密度下可逆比容量为130 mAh·g-1。X射线光电子能谱测试表明,包覆层可以在循环中保持稳定且能抑制LiCoO2材料在高电压下的表面副反应。 相似文献
79.
制备了四碘化5,10,15,20-四(对-N,N,N三甲基苯胺基)卟啉敏化的钛酸盐纳米管(TAPPI-TNTs),并利用甲基橙(MO)作为模型污染物考察了其可见光催化活性。结果表明,TAPPI-TNTs是一个高效的可见光催化剂,在其催化作用下,可见光照射1 h后,甲基橙的降解率为89%。与此相反,纯钛酸盐纳米管并不具有可见光催化活性。此外,TAPPI-TNTs的稳定性较高,可以多次循环使用,在第五次循环中,甲基橙的降解率仍可达到50%以上。这可能是由于带正电荷的卟啉与带负电荷的钛酸盐纳米管之间存在着较强的静电吸引作用,卟啉紧密地吸附在钛酸盐纳米管上,导致卟啉的光激发电子易于向钛酸盐纳米管转移,从而使钛酸盐纳米管得到了有效敏化。 相似文献
80.