磁控溅射法制备CeO_2/PTFE/Nafion复合膜及性能研究

采用磁控溅射法在聚四氟乙烯(PTFE)微孔膜表面溅射CeO_2,制备了CeO_2/PTFE复合膜.利用接触角、X射线光电子能谱(XPS)、扫描电子显微镜(SEM)和拉伸强度等对复合膜的亲水性、元素组成、形貌和机械强度进行测试,研究了溅射时间和溅射功率对膜性能的影响.结果表明,在溅射功率为40 W,溅射时间为120 s时,CeO_2/PTFE复合膜亲水性和拉伸强度都相对较好.在CeO_2/PTFE复合膜上浇铸Nafion树脂,制备的CeO_2/PTFE/Nafion复合膜含水率达到30%,离子电导率达到0.071 S/cm.     

不同EW值的sPTFS/PTFE复合膜性能研究

将两种不同EW值的聚α,β,β＿三氟苯乙烯(sPTFS)树脂浸入到多孔聚四氟乙烯(PTFE)膜的孔中,制成sPTFS/PTFE复合膜用于质子交换膜燃料电池(PEMFC).并对该复合膜的吸水率,电导率,机械强度及其装配的电池性能进行了测试.与其它均质膜相比,复合膜明显降低了吸水率,同时也降低了电导率,增加了机械强度.在电池温度为80℃,H2/O2压力为0.2/0.2MPa条件下,两种复合膜装配电池的性能优于Nofion 115膜.低EW值的复合膜电池性能优于高EW值的电池性能,但电池稳定性相对较差.     

熔融纺丝-拉伸法制备PVDF中空纤维膜及其油-水分离性能

以聚偏氟乙烯(PVDF)为成膜聚合物, 聚全氟乙丙烯(FEP)为添加剂, 聚乙二醇(PEG)和氯化钙(CaCl₂)为复合成孔剂, 采用熔融纺丝-拉伸法制备了PVDF中空纤维膜. 在制膜过程中未使用其它溶剂和稀释剂, 实现了制膜过程的相对绿色化. 分析和讨论了拉伸比对PVDF中空纤维膜结构与性能的影响, 测试了纤维膜的孔径分布、 力学性能和油-水分离性能等. 结果表明, 进行拉伸后处理的膜的孔径分布较窄, 在油包水乳液分离测试中, 分离效率均在97%以上, 表现出良好的油-水分离效果.     

质子交换膜燃料电池Nafion/PTFE复合膜的研究

在聚四氟乙烯(PTFE)多孔膜内浸入Nafion树脂,制成Nafion/PTFE复合膜用于质子交换膜燃料电池(PEMFC).该复合膜的Nafion含量在50%左右,在干态和湿态时的拉伸强度及水化/脱水过程中,其尺寸稳定性比Nafion均有所提高.在80 ℃,H2/O2压力为0.2/0.2 MPa条件下,用25 μm厚复合膜组装的电池性能优于Nafion117膜组装电池的性能.测量了复合膜的O2渗透率和含水量并与Nafion膜的性能作了比较.     

高内相比乳液模板法合成多孔材料的研究进展

综述了以高内相比乳液作模板制备多孔材料的研究进展,介绍了油包水(W/O)乳液体系法、水包油(O/W)乳液体系法和超临界CO2法等制备方法、各种多孔材料的泡孔及通道直径、比表面积、密度等性能,以及这类多孔材料在生物医学、有机化学品清除、化学催化、水溶液中固体杂质分离、液相色谱、电化学传感器等领域的应用,并对其发展前景进行了展望。     

碳纳米管/聚苯胺/铁氰化镍复合膜的电化学共聚制备与电容性能

采用循环伏安一步共聚法在碳纳米管修饰的铂基体上制备了电活性碳纳米管/聚苯胺/铁氰化镍(CNTs/PANI/NiHCF)复合膜.用傅立叶变换红外(FT-IR)光谱、X射线能谱仪(EDS)和扫描电镜(SEM)研究了复合膜组成及其表面形貌,并用循环伏安(CV)、恒电流充放电和电化学阻抗(EIS)等测试了复合膜的循环稳定性与电化学容量性能.研究表明:CNTs/PANI/NiHCF复合膜为三维多孔有序的网络状结构,PANI和NiHCF以纳米颗粒形式存在并沿CNTs均匀分布;在电流密度为2mA.cm-2时,CNTs/PANI/NiHCF复合膜的比容量高达262.28F.g-1,比能量为29.51Wh.kg-1,电流密度为10mA.cm-2时比功率可达10228.61W.kg-1;在2000次循环充放电过程中,复合膜的电容量仅衰减19.92%,电荷充放电效率一直保持在99%以上.CNTs/PANI/NiHCF有机-无机杂化膜具有良好的功率特性和快速充放电能力,是一种优异的超级电容器材料.     

制备条件对PANI/PATP/Au和TiO_2-PANI/PATP/Au膜光电化学性能的影响

应用电化学方法在不同条件下制备聚苯胺 (PANI)膜和TiO2 -PANI复合膜 ,并对其光电化学性能进行研究 .实验表明 ,制备条件是影响膜光电化学性能的重要因素 .对氨基硫酚 (PATP)的组装有利于改善PANI膜的附着力 ;部分氧化态PANI膜的光电化学响应明显优于还原态和氧化态PANI膜的光电化学响应 ;部分氧化态PANI膜的厚度对其光电化学性能有一最佳值 ;热处理虽然有利于改善TiO2 的光电化学性能 ,但温度太高 ,将破坏PANI膜的表面结构 ,对于TiO2 -PANI复合膜有一最佳的热处理温度 .优化制备条件大可改善TiO2 -PANI复合膜和PANI膜的光电化学性能     

铂粒子修饰单壁碳纳米管/聚苯胺复合膜对甲醛的电催化氧化

在溶有单壁碳纳米管(SWNTs)的苯胺溶液中, 通过电化学共聚合法成功制备了单壁碳纳米管(SWNT)/聚苯胺(PANI)复合膜. 用电沉积法将铂沉积到SWNT/PANI复合膜上. 样品的成分和形貌分别用XRD和SEM表征. 四探针和电化学交流阻抗的研究表明被PANI包裹的SWNTs整齐地排列在复合膜中, 从而提高了复合膜的电导率, 促进了电荷转移. 循环伏安(CV)说明Pt修饰的SWNT/PANI复合膜对于甲醛氧化具有良好的电催化活性及稳定性. 研究结果表明SWNT/PANI复合膜是一种非常好的催化剂载体, 有着广泛的应用前景.     

聚丙烯/碳酸钙复合无纺布的仿生矿化制备及其在油水分离中的应用

基于仿生矿化中的基质媒介原则,通过交替浸渍矿化过程(alternating soaking process,ASP)制备了表面负载均匀碳酸钙矿物涂层的聚丙烯无纺布有机/无机复合膜.静/动态水下油接触角测试结果表明,矿化膜具有很强的锁水能力,可将水分子吸附在膜表面形成稳定斥油界面,从而对二氯乙烷、正十六烷、石油醚、汽油、柴油等常用油均表现出超疏油(CA>150°)和低油滴黏附(SA<5°)性质.同时无纺布具有三维孔洞相互贯通的独特结构和高孔隙率,使得矿化膜表现出过膜压力低(油水乳液自身重力驱动)和油临界击穿压力高(>10 kPa)的特性.模型油水乳液分离效果实验发现矿化膜对尺寸在2μm以上的乳液油滴有较好的截留作用,可望应用于一些实际工业含油废水的处理.     

Triton X-100微乳液体系中铁的萃取与分离

近年来 ,在以表面活性剂分子有序组合油包水 (W/O)微乳液体系中进行萃取分离已引起人们的重视 [1～ 3] .本文根据微乳液体系较相应胶束有更低的表面张力和更高增溶量的特性 ,首次利用非离子型水包油 (O/W)壬基酚聚氧乙烯醚(Triton X- 1 0 0 )微乳液在无机盐硫酸铵的存在下萃取分离铁 ,与传统的有机溶剂萃取分离方法比较 ,此法具有不挥发、无毒、快速和操作简单等特点 ;与高聚物水溶液体系萃取 ,有相同的萃取效果 ,但药品用量相对减少 .GBC932 AA原子吸收分光光度计 (澳大利亚 ) ;p Hs- 2 5酸度计 (上海雷磁仪器厂 ) .铝试剂为质量分数 …     

Poly(tetrafluoroethylene) composite membranes coated with urchin-like polyaniline hiberarchy: Preparation and properties

Spiny polyaniline (PANI) spheres (urchin-like) were coated on a poly(tetrafluoroethylene) (PTFE) membrane via a counter-diffuse interfacial oxidation polymerization of aniline in an aqueous medium. The produced composite membrane has both unexpected superhydrophilicity and conductivity. The microstructure and morphology of the composite membrane were characterized by FTIR, UV-vis, XRD, TGA, and SEM. Effects of reagent concentrations and polymerization time on the membrane morphology and properties were studied systematically. A possible formation mechanism of the urchin-like polyaniline nanospheres on PTFE surface has been briefly discussed. The co-effect of both spherical micelles formed by Nafion and nanofibrous micelles formed by aniline/p-toluenesulfonic acid was considered to be a reason to produce the urchin-like PANI nanospheres. The PTFE/Nafion/PANI composite membrane showed a convertible hydrophilic/hydrophobic feature via adjusting acidity/alkalinity of an aqueous medium and also was able to adsorb heavy metal-ions from the medium.     

An ultrathin self-humidifying membrane for PEM fuel cell application: fabrication, characterization, and experimental analysis

An ultrathin poly(tetrafluoroethylene) (PTFE)-reinforced multilayer self-humidifying composite membrane (20 microm, thick) is developed. The membrane is composed of Nafion-impregnated porous PTFE composite as the central layer, and SiO2 supported nanosized Pt particles (Pt-SiO2) imbedded into the Nafion as the two side layers. The proton exchange membrane (PEM) fuel cell employing the self-humidifying membrane (Pt-SiO2/NP) turns out a peak power density of 1.40 W cm(-2) and an open circuit voltage (OCV) of 1.032 V under dry H2/O2 condition. The excellent performance is attributed to the combined result of both the accelerated water back-diffusion in the thin membrane and the adsorbing/releasing water properties of the Pt-SiO2 catalyst in the side layers. Moreover, the inclusion of the hygroscopic Pt-SiO2 catalyst inside the membrane results in an enhanced anode self-humidification capability and also the decreased cathode polarization (accordingly an improved cell OCV). Several techniques, such as transmission electronic microscopy, scanning electronic microscopy, energy dispersive spectroscopy, thermal analysis and electrochemical impedance spectroscopy etc., are employed to characterize the Pt-SiO2/NP membrane. The results are discussed in comparison with the plain Nafion/PTFE membrane (NP). It is established that the reverse net water drag (from the cathode to the anode) across the Pt-SiO2/NP membrane reaches 0.16 H2O/H+. This implies a good hydration of the Pt-SiO2/NP membrane and thus ensures an excellent PEM fuel cell performance under self-humidification operation.     

单分散P(St-BA-AN)/PANI核壳结构复合微球的制备与电性能

以苯乙烯(St)、丙烯酸丁酯(BA)和丙烯腈(AN)为单体, 采用乳液聚合的方法制备出单分散苯乙烯-丙烯酸丁酯-丙烯腈三元共聚物[P(St-BA-AN)]种子微球, 再在该种子微球表面包覆聚苯胺(PANI), 制得P(St-BA-AN)/PANI核壳结构复合微球. 采用扫描电镜(SEM)、透射电镜(TEM)、傅里叶变换红外透射光谱(FTIR)和漫反射光谱等测试手段对所制备的种子微球和复合微球的形态、结构和形成机理进行了研究, 并用四探针法测定了核壳结构复合物的导电性. 研究结果表明, 通过改变种子乳液共聚物的组成和加入苯胺的量及氧化剂的量等条件可调控复合微球的电导率. 与P(St-BA)/PANI核壳结构复合微球相比, 在核组成中引入了氰基的P(St-BA-AN)/PANI核壳结构复合微球的电导率明显提高, 当加入苯胺的量为P(St-BA-AN)种子微球与苯胺单体总质量分数的40%时, 其电导率可达到0.71 S/cm. 红外光谱结果证实了P(St-BA-AN)种子微球中的氰基和壳层中聚苯胺的胺基之间存在某种相互作用, 导致核壳结构复合物电导率的提高.     

聚苯胺/石墨烯涂覆型阴离子交换固定相的制备及表征

该文以聚苯胺/石墨烯复合材料为涂覆材料,制备了一种涂覆型阴离子交换固定相。首先以苯胺和石墨烯为原料制备聚苯胺/石墨烯复合材料,并通过物理吸附涂覆在聚苯乙烯-二乙烯苯微球表面;然后以聚苯胺中的氮原子为反应位点,通过季铵化制备一系列具有不同交换容量的涂覆型阴离子交换固定相。通过扫描电镜(SEM)、傅里叶红外光谱(FT-IR)和元素分析(EA)对该涂覆型阴离子交换固定相进行表征,结果表明聚苯胺/石墨烯成功地涂覆在微球表面且发生了季铵化。通过分离常规阴离子和有机酸,对自制阴离子交换色谱柱的色谱性能进行评价。结果显示,8次季铵化的聚苯胺/石墨烯涂覆聚苯乙烯-二乙烯苯阴离子交换色谱柱对常规阴离子和有机酸呈现良好的分离效果。     

反渗透膜微结构的调控及海水脱硼性能的提升

通过引入聚乙烯亚胺(PEI)链与对叠氮苯甲酸(ABA)分子对薄层芳香聚酰胺复合反渗透膜(TFC)进行接枝改性, 采用傅里叶衰减全反射红外光谱(ATR-FTIR)和X射线光电子能谱(XPS)分析了反渗透膜活性分离层的化学组成和结构, 用静态水接触角仪与Zeta电位仪测试了反渗透膜表面的亲疏水性和电荷性质, 并利用扫描电子显微镜(SEM)及原子力显微镜(AFM)观察其表面形貌, 测试了反渗透膜在苦咸水与海水条件下的分离性能. 实验结果表明, 使用PEI与ABA对反渗透膜改性后, 提升了其分离层的致密度, 使硼渗透通过反渗透膜时的传质阻力变大, 从而将改性反渗透膜(TFC-PEI-ABA)对硼的截留率提升至90.45%, 达到了世界卫生组织对水质的要求.     

Pervaporation separation of water + isopropanol mixtures using novel nanocomposite membranes of poly(vinyl alcohol) and polyaniline

Novel nanocomposite polymeric membranes containing nanosized (30–100 nm) polyaniline (PANI) particles dispersed in poly(vinyl alcohol) (PVA) were prepared and used in the pervaporation separation of water–isopropanol feed mixtures ranging from 10 to 50 mass% of water at 30 °C. Of the three nanocomposite membranes prepared, the membrane containing 40:60 surface atomic concentration ratio of PANI:PVA produced the highest selectivity of 564 compared to a value of 77 observed for the plain PVA membrane. Flux of the nanocomposite membranes was lower than those observed for the plain PVA membrane, but selectivity improved considerably. Membranes were characterized by differential scanning calorimetry, dynamic mechanical thermal analyzer, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and scanning electron microscopy. The highest selectivity with the lowest flux was observed for 10 mass% water containing feed mixture. Flux increased with increasing amount of water in the feed, but selectivity decreased considerably. These results were attributed to the acid-doped PANI particles in the PVA membrane as a result of change in the micromorphology of the nanocomposite membranes. In addition, molar mass between cross-links and fractional free volume of the membranes are responsible for the varying membrane performance. Temperature effect on permeability was investigated for 10 mass% water containing feed with the membrane containing higher concentration of PANI particles, the presence of which could be responsible for varied effect of water permeation through the membrane. Membranes of this study could remove as much as 98% of water from the feed.     

The Electrochemical Properties of Nanocomposite Films Obtained by Chemical In Situ Polymerization of Aniline and Carbon Nanostructures

Interactions between the π bonds in the aromatic rings of polyaniline (PANI) with carbon nanostructures (CNs) facilitate charge transfer between the two components. Different types of phenyleneamine‐terminated CNs, including carbon nano‐onions (CNOs) and single‐walled and multi‐walled carbon nanotubes (SWNTs and MWNTs, respectively), were prepared as templates, and the CN/PANI nanocomposites were easily prepared with uniform core–shell structures. By varying the ratio of the aniline monomers relative to the CNs in the in situ chemical polymerization process, the thickness of the PANI layers was effectively controlled. The morphological and electrical properties of the nanocomposite were determined and compared. The thickness and structure of the PANI films on the CNs were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), and infrared spectroscopy. TEM and SEM revealed that the composite films consisted of nanoporous networks of CNs coated with polymeric aniline. The electrochemical properties of the composites were investigated by cyclic voltammetry and electrochemical impedance spectroscopy. These studies showed that the CN/PANI composite films had lower resistance than pure polymeric films of PANI, and the presence of CNs much improved the mechanical stability. The specific electrochemical capacitance of the CNO/PANI composite films was significantly larger than for pure PANI.     

静电纺丝法制备聚丙烯腈/聚苯胺复合纳米纤维及其表征

利用静电纺丝技术,以聚丙烯腈(PAN)和苯胺(ANI)为前驱物,用过硫酸胺(APS)溶液在低温下缓慢氧化聚合,制备了PAN/PANI复合纳米纤维,直径约500 nm.通过扫描电子显微镜(SEM)、红外光谱(FTIR)、X射线衍射(XRD)和激光拉曼(RAMAN)光谱仪等测试手段对材料的形貌和结构进行了表征.探讨了材料制备过程中影响纤维形貌、尺寸、均匀度的因素和PANI含量对复合纤维导电性能的影响,结果表明,PAN浓度、ANI的加入量和电压是影响纤维特性的主要因素;PANI在PAN基体中呈纳米尺寸分布,复合纳米纤维具有良好的导电性能,导电率可达10-2S/cm.     

热解二氧化钛/聚苯胺制备高效非贵金属氧还原电催化剂

为了克服传统Pt系催化剂价格昂贵、稳定性差的缺点,采用热解新型Ti O2/聚苯胺(PANI)复合物的方法合成了Ti O2/C催化剂.用扫描电子显微镜、X射线光电子能谱、X射线衍射、傅里叶变换红外光谱、拉曼光谱、透射电子显微镜、循环伏安法和线性扫描伏安法等方法研究了热处理和PANI复合比例对复合物的形貌、成键、晶相组成及氧还原性能的影响.结果表明,PANI与Ti O2间存在相互作用,可以抑制Ti O2的团聚和锐钛矿向金红石的转变.热处理制得Ti O2/C的氧还原活性随着PANI载体含量增加先升高后降低,PANI和Ti O2质量比为35/100时,催化剂的氧还原活性最高.同时,循环伏安和时间-电流曲线测试表明,已制备的复合材料在催化氧还原反应进行时具有较好的稳定性.     

Synthesis of polyaniline/Q-CdSe composite via ultrasonically assisted dynamic inverse emulsion polymerization

In this communication, polyaniline/CdSe quantum dots (PANI/Q-CdSe) composite was successfully synthesized via in situ ultrasonically assisted dynamic inverse emulsion polymerization. The synthesized PANI-coated Q-CdSe composite was characterized by field emission transmission electron microscopy showed that the CdSe quantum dots have an average size of around ca. 5 nm were dispersed in the PANI matrix. X-ray diffraction, Fourier transform infrared spectrum (FT-IR) and UV-visible spectrum were used to characterize the structure of the obtained PANI/Q-CdSe composite. FT-IR spectra indicated that the polymer was highly doped and existed in conducting emeraldine salt form. The obtained PANI/Q-CdSe composite showed significant improvement in the thermal behavior as indicated by TGA thermograph. The presented dynamic polymerization process is very fast and produces stable colloidal dispersion. This approach provides a one-step, simple, general, and inexpensive method for the preparation of PANI/Q-CdSe composite.