聚乙二醇修饰纳米二氧化锡的制备及气敏特性

以五水四氯化锡为原材料,聚乙二醇为表面包覆剂,用沉淀法制备出二氧化锡纳米粉体.将制得的二氧化锡纳米粉体经过研磨、涂覆、烧结、焊接、老化等步骤即制得旁热式烧结型二氧化锡气敏元件.取少量二氧化锡纳米粉体采用X射线衍射、比表面测试、扫描电镜和透射电镜等测试手段对材料的结构、比表面积和形貌进行了表征;采用静态配气法测试了气敏元件对乙醇、甲醛、丙酮、甲醇等气体的气敏性能.结果表明:制备的二气化锡粉体粒径非常小且均一性比较好,颗粒大小约为5～8nm;比表面积极大,最高达到每克73.29平方米,具有多孔结构,最可几孔径为4.7～6.1nm,多孔结构可形成气体通道有利于气体分子扩散,从而提高气敏性能.通过添加聚乙二醇作为表面包覆剂对二氧化锡进行修饰,提高了二氧化锡材料的气敏性能,研究表明各元件对乙醇、甲醛、丙酮、甲醇等气体都具有很高的灵敏度,具有较大的应用前景.     

蝶翅状Ag/TiO_2 NTs的制备及气相光催化性能研究

采用二次氧化法制备蝶翅状阵列式二氧化钛纳米管(TiO2NTs),通过光化学还原不同浓度Ag+,在其表面均匀负载Ag纳米颗粒(Ag/TiO2NTs).利用扫描电镜(SEM)、能谱分析仪(EDS)、X线衍射仪(XRD)和紫外漫反射(UV-DRS)等对纳米管的形貌、元素组成、晶型和紫外—可见漫反射吸收光谱进行表征,利用傅里叶红外光谱仪(FTIR)测试TiO2NTs和Ag/TiO2NTs对气相甲醇的紫外光催化降解性能.结果表明,Ag/TiO2NTs(0.01mol/L)在紫外光区表现出较好的吸收性能,肖特基结的形成使其光催化活性比纯TiO2NTs有显著提高.     

普通钠钙玻璃SCC特性的测试与分析

本文探索出一种玻璃材料SCC特性的有效测试方法,并对普通钠钙玻璃在水,甲醇和甲酰胺三种介质申的SCC特性进行了测试与分析。结果表明,其da/dt-K_I曲线均无平台阶段,这是因为三种介质均是普通钠钙玻璃的活性促进剂。三种介质的SCC敏感性依次为水>甲醇>甲酰胺。进一步讨论认为,SCC敏感性与介质的未共享电子轨道的非对称性及给质子键的活性成正相关关系。     

水浴法后处理制备锐钛矿纳米管的研究

采用浓碱水热法,以P25为前驱体,在10mol/L的NaOH溶液中110℃加热制备了钛酸纳米管.将纳米管分散于去离子水中,80℃水浴加热制备出了锐钛矿纳米管.对纳米管进行TEM,DRS,XRD,BET分析测试,结果表明:水浴法后处理制备的锐钛矿纳米管维持了钛酸纳米管的基础结构,比表面一定程度下降,但是其晶型向催化活性高的锐钛矿转变,对于紫外光的吸收增强,吸收边界发生了一定程度的红移.降解活性艳红X-3B测试了其光催化性能,结果表明:80℃水浴法后处理后,纳米管的光催化活性得到显著提高,其中水浴12h得到纳米管催化活性最好.     

质子交换膜燃料电池运行工况参数敏感性分析

建立了一维瞬态多相流燃料电池机理模型和全局敏感性分析模型,研究了运行温度、气体压强、化学计量比以及相对湿度对输出性能的影响规律和影响程度。结果表明：高功率负荷条件下,运行温度的变化会造成更明显的性能波动;提高进气压强和化学计量比能够增强输出性能;相对湿度过低产生的“膜干”现象在低电流密度区域更加明显;经过敏感性量化分析,本文将9类工况参数划分为高敏感、较敏感和不敏感参数;随着电流密度的增大,阴极进气化学计量比、阴阳极进气湿度的敏感性较大且整体呈上升趋势。     

Nd2O3—SnO2薄膜气敏元件的研制

研究了Ｎｄ２Ｏ３－ＳｎＯ２复合薄膜气敏元件的制作工艺和敏感性能，测量结果表明，这种元件对乙炔气体敏感，且具有选择性好，灵敏度高等优点。     

聚（3，4-乙撑二氧噻吩）:聚苯乙烯磺酸阳极缓冲材料的改性研究

聚（3,4-乙撑二氧噻吩）:聚苯乙烯磺酸（PEDOT:PSS）是导电聚合物领域的明星分子,具备可见光透过率高、易低温溶液加工且廉价等优点,常作为标准阳极缓冲材料（ABM）广泛应用于叠层有机光电器件领域中。然而,随着半导体材料和器件结构的飞速发展,对ABM提出了更高要求,当前PEDOT:PSS的性质参数无法很好满足新一代有机光电器件的需要（如电导率较低、功函数较小、酸性较强和亲水性较强等）,成为制约有机光电器件性能提升的重要瓶颈。改变导电聚合物的结构可有效优化其性质参数、大幅提升有机光电器件性能,备受关注。本文首先详细阐述PEDOT:PSS的结构特征（包括溶液和固体两种状态的结构特征）,揭示PEDOT:PSS的结构与性质的关系,然后综述外加剂和新型掺杂剂（PSS替代物）改变PEDOT导电聚合物结构和性质的改性研究进展,最后展望PEDOT:PSS ABM领域的改性研究发展趋势。     

镁离子掺杂TiO_2纳米管的水热合成、表征及光催化性能研究

以水热法制备的TiO2钛纳米管为模板,在水溶液中通过超声辅助离子交换法合成了镁掺杂的TiO2纳米管/棒。通过扫描电镜、X-射线衍射、光催化等多种测试手段对产物进行了表征,讨论了镁掺杂前后对TiO2纳米管形貌和结构的影响。实验结果表明,镁的掺杂对TiO2纳米管的催化性能有较大提高。     

复合乳化剂浓度对PANI／PEDOT复合阳极材料导电性及结构的影响

以原位聚合法制备了导电聚合物聚苯胺／聚3,4-乙烯二氧噻吩（PANI／PEDOT）复合阳极材料．研究了复合乳化剂浓度对PANI／PEDOT复合阳极材料的电化学性能和结构的影响．用线性扫描、交流阻抗、傅里叶变换红外光谱和x-射线衍射对所得的复合阳极材料的电化学特性、物相和结构进行了表征．结果表明,当复合乳化剂浓度为0．2mol／L时,PANI／PEDOT复合阳极材料具有较好的导电性,所得复合材料的分子链有序性较好,结构规整,结晶性好．     

ZnO及Au-ZnO中空微球的制备及其气敏性研究

以二水合醋酸锌及氯金酸为主要原料,通过微波水热法快速合成ZnO及Au-ZnO.使用X射线衍射、扫描电子显微镜和透射电子显微镜对样品的组成及结构进行表征.研究发现,制备的材料具有中空微球结构,直径约为4μm.以制得微球构筑旁热式气敏元件,并采用静态配气法测试了不同掺金量的气敏元件对乙醇、甲醇、丙酮和氨气等气体的敏感性能.分析结果表明,小粒径的Au纳米粒子负载在ZnO表面,提高了表面的粗糙度和比表面积,除此之外,Au活化了乙醇分子,促进了乙醇和氧离子在表面的化学反应,导致Au负载的ZnO对乙醇具有灵敏度高、检测下限低、选择性好、响应和恢复迅速等优点.     

Platinum wire implants coated with PEDOT/carbon nanotube conducting polymer films in the brain of rats: A histological evaluation

Platinum (Pt) implants coated with poly (3, 4-ethylenedioxythiophene)/carbon nanotube (PEDOT/CNT) composite films were implanted into the brain of rats, and the brain response was evaluated 6 weeks after the implantation. The surface morphology of Pt implants with and without the PEDOT/CNT coating was studied using scanning electron microscopy (SEM). After 6 weeks post-implantation, the expression of laminin (vascular endothelial marker) and neuronal nuclei (NeuN, neuronal marker) were evaluated by immnohistochemistry. It is revealed that the obvious improvements of the surface density of blood vessels and neurons aound the Pt implants with the coating, which were evidenced by laminin and NeuN staining in the zone within the distance of 150 μm to the implant interface. These results suggest the PEDOT/CNT composite films can improve the biocompatibility of the Pt electrodes while it is implanted in brain.     

Structures and properties of PEDOT nanotubes prepared by a template synthesis method

PEDOT nanotubes were prepared by a template synthesis method. Based on our template, it was deduced that there are two successive processes in the formation of nanotubes. The first step is soakage of the porous templates by a polymer solution, and the second step is adsorption of free charged cationic groups and doped PEDOT onto the template surface with negative charges. XRD results showed that well orientated PEDOT chains were formed during the synthesis, moreover the arrange conductivity of molecular chains strongly affect the structures of PEDOT nanotubes. The nanotubes were measured to be about 5.5–17.6 S/cm, which is higher than that of nanotube pellet due to the high contact resistance between the adjacent nanotubes. Funded National Natural Science Foundation of China(No.: 60372002)     

Gas sensitivity of poly (3, 4-ethylene dioxythiophene) prepared by a modified LB film method

An arachidic acid/poly (3, 4-ethylene dioxythiophene) (AA/PEDOT) multilayer Langmuir-Blodgett (LB) film was prepared by a modified LB film method. The theories were utilized to explain the effects between HCl molecule and LB film. The gas sensitivity mechanism of poly (3, 4-ethylene dioxythiophene) (PEDOT) multilayer film can be explained by the charge transfer between p system of PEDOT and oxidization HCl system. The gas sensitivity of PEDOT LB film deposited interdigital electrode to HCl was tested. The results showed that film thickness, treating temperature, deposition speed had different influence on film gas sensitivity. The AA/PEDOT film deposited device exhibited nonlinear behavior to HCl gas at lower concentration (20-60 ppm) and linear response behavior at higher gas concentration was observed. The time of the compound LB film of the AA/PEDOT responding to the 30 ppm HCl gas is about 20 seconds, which is far quicker than the time of the film to the PEDOTPRESS film(about 80 seconds). It is not higher film press to better film. When the film press attains 45 mNs/m, the sensitivity of the AA/PEDOT film on the contrary descends.     

Synthesis and Bio-activities of Poly(3,4-ethylenedioxythiophene)(PEDOT)/Poly(styrene sulfonate)(PSS)/Gelatin Layer on Indium Tin Oxide(ITO)-coated Glass

Poly(3, 4-ethylenedioxythiophene)(PEDOT), together with its dopes, such as poly(styrene sulfonate)(PSS), has been acknowledged to have a wide range of biomedical applications as an important conducting polymer. In this study, gelatin can be polymerized into PEDOT/PSS polymers on indium tin oxide(ITO)-coated glass. PEDOT/PSS/gelatin layer on ITO-coated glass significantly decreases electrochemical impedance spectroscopy(EIS) and increases charge delivery capacity relative to the gelatin layer and bare ITOcoated glass, comparable to the PEDOT/PSS layer on ITO-coated glass. PEDOT/PSS/gelatin layer on ITOcoated glass enhances pheochromocytoma(PC 12) cell affinity, possesses a high biocompatibility and promotes PC 12 cell growth by delivery of electrical stimulation. These results suggest that gelatin can be incorporated into the PEDOT/PSS polymers through electrochemical polymerization and the PEDOT/PSS/gelatin layer on ITO-coated glass possesses high electrochemical and biological activities.     

Analysis on the characteristic properties of PEDOT nano-particle based on reversed micelle method

Based on the study of a new type of conducting polymer poly (3,4-ethylenedioxythiophene) (PEDOT),we focussed on the preparation and characteristics of PEDOT nanoparticles made by reversed micelle method.Moreover,we deeply investigated the optical,electrical and the thermal stability of PEDOT nanoparticles.The main results are as follows: the small-sized PEDOT nanoparticles were prepared and utilized by different methods,such as ultraviolet/visible (UV-Vis) spectroscopy,Fourier-transform infrared (FT- IR) spectrum,scanning electron microscopy(SEM) and so on.The results show that the amount of oxidizer,ultrasonic treatment,polymerizing temperature and doping degree can influent morphology,electrical ability and gas sensitivity of PEDOT nanoparticles.The Bragg peaks of nanoparticles at 6.7°,12.7°,25° were observed by XRD and the better orientation of molecular chain was attributed to the effective doping of toluene-p-sulfonic acid,which also resulted in an enhancement of thermal stability of nanoparticles than conventional PEDOT.     

UV irradiation induced conductivity improvement in poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) film

We describe a simple method to increase the conductivity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)film by exposure to ultraviolet(UV)light in vacuum.Up to four order of conductivity improvement(from 10 3to 50 S/cm)is achieved by irradiating PEDOT:PSS film with 254 nm ultraviolet(UV)light.Increased conductivity in UV treated PEDOT:PSS film is stable under ambient exposure.The mechanism for conductivity improvement is investigated by current-voltage measurement,atomic force microscopy,and absorption spectrum.Photo-cross-linking of PSS chains is determined as the reason for conductivity improvement.Our result demonstrates that UV treatment is capable of modifying the conductivity of PEDOT:PSS film independent of the process of film formation.     

不同电导率的PEDOT对聚合物光电池性能的影响

采用几种具有不同电导率的PEDOT(poly(3,4-ethylene dioxythiophene)),研究其对器件性能的影响,结果表明高电导率的PEDOT与ITO(Indium tin oxide)一起作为光电池的阳极,有利于光电池能量转换效率的提高.探讨了高电导率PEDOT的厚度与器件性能之间的相关性,表明在保证器件不漏电的前提下PEDOT的厚度越薄越好.     

CdS quantum dots-sensitized TiO2 nanotube arrays for solar cells

CdS quantum dots(QDs) sensitized TiO2 nanotube arrays photoelectrodes were investigated for their photovoltaic performance of quantum dots-sensitized solar cells. The highly ordered TiO2 nanotube arrays(TNAs) were synthesized on Ti foils by anodic oxidation method. Then CdS quantum dots were deposited onto the TiO2 nanotube arrays by successive ionic layer absorption and reaction(SILAR) method to serve as the sensitizers. Cd(NO3)2 and Na2S were used as the precursor materials of Cd+ and S2- ions, respectively. It is found that the CdS QDs sensitizer may significantly increase the light response of TiO2 nanotube arrays. With increasing CdS QDs deposition cycles, the visible light response increases. Maximum photocurrent was obtained for the QDs that have an absorption peak at about 500 nm. Under AM 1.5 G illuminations(100 mW cm-2), a 4.85 mA/cm2 short circuit current density was achieved, and the maximium energy conversion efficiency of the as-prepared CdS QDs-sensitized TNAs solar cells was obtained as high as 0.81 % at five SILAR cycles.     

聚乙撑二氧噻吩/多壁碳纳米管复合材料的制备与电化学性能研究

以三氯化铁为氧化剂,通过原位聚合法制备聚乙撑二氧噻吩/多壁碳纳米管复合材料.热重分析结果表明：聚乙撑二氧噻吩/多壁碳纳米管复合材料相对于聚乙撑二氧噻吩具有更好的热稳定性;采用傅里叶变换红外光谱（FT-IR）、扫描电镜（SEM）对产物的结构与形貌进行表征,聚乙撑二氧噻吩在多壁碳纳米管表面形成了均匀的包覆层,两者之间存在一定的界面作用.在1 mol/L氯化钾（KCl）溶液中,采用循环伏安测试法（CV）研究样品的电化学性能,聚乙撑二氧噻吩/多壁碳纳米管复合材料的比电容可达139.8 F/g.