复合阴极材料La1-xSrxCuO3-δ-SDC的制备及电学性能

合成具有单相正交钙钛矿结构的La1-xSrxCuO3-δ(x=0.15, 0.2, 0.3, 0.4)系列样品, 碘量滴定法实验结果表明, 随着Sr掺入量的增加, Cu3+离子的含量逐渐增加. 电学性能研究结果表明, La0.7Sr0.3CuO3-δ电导率最高, 与La0.6Sr0.4CoO3-δ相比, La0.7Sr0.3CuO3-δ具有更好的电化学性能, 可作为一种新的中温固体氧化物燃料电池(IT-SOFC)阴极材料. 将La0.7Sr0.3CuO3-δ与不同质量比的中温电解质Ce0.85Sm0.15O2-δ(SDC) 固相混合, 制备复合阴极材料, 电化学性能测试结果表明, 掺入适量的SDC有利于降低La0.7Sr0.3CuO3-δ电极的极化, 获得性能更优越的IT-SOFC阴极材料, 提高在中温区单电池的输出功率.     

Influence of Calcination on the Properties of Nickel Oxide-Samarium Doped Ceria Carbonate (NiO-SDCC) Composite Anodes

Apart from its composition, the starting powder properties such as particle size potentially affect the triple phase boundary and the electrochemical performance. Calcination process has been identified as one of the factors that influence the particle size of the composite anode powders. This study investigates the correlation between calcination temperature and properties (i.e., chemical, physical, and thermal) of NiO–samarium-doped ceria carbonate (SDCC) composite anodes. NiO–SDCC composite anode powder was prepared with NiO and SDCC through high-energy ball milling. The resultant composite powder was subjected to calcination at various temperatures ranging from 600 °C to 800 °C. Characterizations of the composite anode were performed through X-ray diffraction (XRD), Fourier transform infrared spectroscopy, energy dispersive spectroscopy, field emission scanning electron microscopy (FESEM), thermogravimetric analysis (TGA), dilatometry, and porosity measurements. The composite anodes exhibited good chemical compatibility during XRD after calcination and sintering. The FTIR result verified the existence of carbonates in all the composite anodes. The increment in calcination temperature from 600 °C to 800 °C resulted in the growth of nanoscale particles, as evidenced by the FESEM micrographs and crystallite size. Nonetheless, the porosity obtained remained within the acceptable range for a good anodic reaction (20% to 40%). The TGA results showed gradual mass loss in the range of 400 °C to 600 °C (within the low-temperature solid oxide fuel cell region). The composite anodes calcined at 600 °C and 700 °C revealed a good thermal expansion coefficient that matches that of the SDCC electrolyte.     

DDACLB膜的电学性质研究（I）-电导率

沉积在聚脂基片上的表面软化剂DDAC多分子层,在不同的湿度条件下,其横向导电特性标志该表面活性剂在纤维表面处理过程中驱除静电能力的大小。由原子力显微镜（AFM）图像表明,DDAC的2、4、8多分子层薄膜上的结晶颗粒随层数的增加而增大,因此采用电导率描述其导电性质并借助薄膜电阻加以解释。对复合分子层的电导率的非线性变化除借用了半导体物理学中的渗透理论（PercolationTheory）加以解释外,还建立了线束重叠（Patch-Overlapping）模型以讨论电流渗透中的饱和现象。得出了提高相对湿度对可使流经多分子层的电流强度增加的结论同时又对膜厚、湿度对电流强度的贡献及其相互制约的关系提出了理论解释。     

Preparation and Properties of Biodegradable Spent Tea Leaf Powder/Poly(Propylene Carbonate) Composite Films

The aim of the present work is to develop novel bio-based lightweight material with improved tensile and thermal properties. Spent tea leaf powder (STLP) was used as a filler to improve the tensile and thermal properties of polypropylene carbonate (PPC). Tea is an important material used in hotels and households, and spent tea leaf is a resulting solid waste. Composite films with STLP were obtained by the solution casting method. These films were characterized by optical and scanning electron microscopy, Fourier transform-infrared spectroscopy, thermogravimetric analysis, and tensile testing to examine the effect of filler content on the properties of the composites. The results showed that composite films have increased tensile strength due to enhanced interfacial adhesion between the filler and the matrix. In addition, the composite films also exhibited higher thermal degradation temperatures than pure polypropylene carbonate. The morphology results indicate that there is a good interface interaction between STLP and PPC. Results of the study reveal STLP to be a promising green filler for polymer plastics.     

Permittivity and electric conductivity of aqueous alumina (40 nm) nanofluids at different temperatures

Aiming to study the effect of nanoparticle size on electric properties, the effective relative permittivity and electric conductivity of suspensions of 40 nm particles of aluminium oxide (alumina) in base Milli-Q and Milli-Ro water were determined at six different temperatures in the range (298.15 to 348.15) K, and at eight different concentrations up to 7% mass (2% volume). Present results are compared with previously published values for the same colloids containing 15 nm particles. Empirical equations for describing the experimental data are given. This study demonstrates the importance of the particle size, volume fraction of nanoparticles, temperature and water purity on the effective relative permittivity and electric conductivity of alumina nanoparticles suspensions. Trends for changes in permittivity enhancement and in electric conductivity enhancement with temperature and concentration are examined and discussed. Classical theoretical models in the study of permittivity and conductivity are applied. A summary is given for the effect of size ((15 and 40) nm), concentration (0.25 to 2)% volume and temperature (298.15 to 348.15) K on the behavior of these nanofluids.     

Fabrication and Properties of Conducting Polypyrrole/SWNT‐PABS Composite Films and Nanotubes

We report the electropolymerization and characterization of polypyrrole films doped with poly(m‐aminobenzene sulfonic acid (PABS) functionalized single‐walled nanotubes (SWNT) (PPy/SWNT‐PABS). The negatively charged water‐soluble SWNT‐PABS served as anionic dopant during the electropolymerization to synthesize PPy/SWNT‐PABS composite films. The synthetic, morphological and electrical properties of PPy/SWNT‐PABS films and chloride doped polypyrrole (PPy/Cl) films were compared. Characterization was performed by cyclic voltammetry, atomic force microscopy (AFM), scanning electron microscopy (SEM) and Raman spectroscopy. SEM and AFM images revealed that the incorporation of SWNT‐PABS significantly altered the morphology of the PPy. Cyclic voltammetry showed improved electrochemical properties of PPy/SWNT‐PABS films as compared to PPy/Cl films. Raman Spectroscopy confirmed the presence of SWNT‐PABS within composite films. Field effect transistor (FET) and electrical characterization studies show that the incorporation of the SWNT‐PABS increased the electronic performance of PPy/SWNT‐PABS films when compared to PPy/Cl films. Finally, we fabricated PPy/SWNT‐PABS nanotubes which may lead to potential applications to sensors and other electronic devices.     

Electrochemiluminescence Characterization of Poly(luminol‐benzidine) Composite Films and Their Analytical Application

A composite film of poly(luminol‐benzidine) was prepared on the graphite electrode surface by electropolymerizing luminol and benzidine in acidic medium. It was found that the poly(luminol‐benzidine) composite film presented better electrochemiluminescence (ECL) analytical performances for H₂O₂ than that of the polyluminol film. Based on these findings, a more sensitive ECL sensor for H₂O₂ was developed. At the same time, our investigating results on this composite film revealed that, as a real ECL luminophor in this composite film, the polymeric 3‐aminophthalate presented higher fluorescence quantum yield than that in the pure polyluminol film, which suggested that the excellent ECL performances of the composite film may originate from the enhancement of the ECL luminophor quantum yield. Based on these results, a new method to improve the ECL analytical performances of the polymeric luminol was also proposed.     

Enhancement in Chemiluminescence by Carbonate for Cobalt(II)‐catalyzed Oxidation of Luminol with Hydrogen Peroxide

Chemiluminescence (CL) from the cobalt(II)‐catalyzed oxidation of luminol with hydrogen peroxide was dramatically enhanced by the presence of carbonate. The CL signal increases by several orders of magnitude over a wide range of concentrations of Co(II), luminol, or hydrogen peroxide. A limit of detection of 10^?12 M for Co(II) and luminol and 10^?8 M for hydrogen peroxide can be achieved. The CL emission spectrum exhibits a maximum at 425 nm, indicating that the excited 3‐aminophthalate is the emitting species. ESR spin‐trapping experiments revealed a large increase in the production of hydroxyl and carbonate radicals by the presence of carbonate, which is responsible for the enormous CL enhancement. Uric acid, ascorbic acid, acetaminophen, and p‐hydroxyphenyl acetic acid are capable of scavenging the radicals, thereby inhibiting the CL emission. The inhibition of CL intensity can be used to determine these substances at the sub‐micromolar level.     

Synthesis,Structure, and Properties of SrC(NH)3, a Nitrogen‐Based Carbonate Analogue with the Trinacria Motif

Strontium guanidinate, SrC(NH)₃, the first compound with a doubly deprotonated guanidine unit, was synthesized from strontium and guanidine in liquid ammonia and characterized by X‐ray and neutron diffraction, IR spectroscopy, and density‐functional theory including harmonic phonon calculations. The compound crystallizes in the hexagonal space group P6₃/m, constitutes the nitrogen analogue of strontium carbonate, SrCO₃, and its structure follows a layered motif between Sr²⁺ ions and complex anions of the type C(NH)₃^2?; the anions adopt the peculiar trinacria shape. A comparison of theoretical phonons with experimental IR bands as well as quantum‐chemical bonding analyses yield a first insight into bonding and packing of the formerly unknown anion in the crystal.     

Electrical and humidity characterization of m-NA doped Au/PVA nanocomposites

The Meta-Nitroaniline (m-NA) doped (by varying weight percentage (wt. %)) gold/polyvinyl alcohol (Au/PVA) nanocomposites were synthesized using gold salt and hydrazine hydrate (HH) by in situ process. The composite was coated on ceramic rods having two end electrodes by drop casting method for studying their electrical behavior at different relative humidity (RH) levels, ranging from 4 to 95% RH at room temperature. The optimized wt. % was used to prepare coatings of various thicknesses (20-40 μm) of the films. As the humidity decreases, the resistance increases. The low humidity sensing characteristic can be tailored by varying wt. % of m-NA and thicknesses of the nanocomposite films. The resistive-humidity sensor shows two regions of sensitivity having highest sensitivity for lower RH. The sensor response and recovery time is about 6-10 s and 52 s respectively. The dynamic range of variation of the resistance allows a promising use of the films as a humidity sensor. The material was characterized by X-ray diffraction (XRD) and impedance spectroscopy at 60% RH.     

Gold(III) Complexes of Asymmetrically Aryl‐Substituted 1,2‐Dithiolene Ligands Featuring Potential‐Controlled Spectroscopic Properties: An Insight into the Electronic Properties of bis(Pyren‐1‐yl‐ethylene‐1,2‐dithiolato)Gold(III)

The electrochemical, UV/Vis–NIR absorption, and emission‐spectroscopic features of (TBA⁺)( 1 ⁻) and the corresponding neutral complex 1 were investigated (TBA⁺=tetrabutylammonium; 1 ⁻=[Au^III(Pyr,H‐edt)₂]⁻; Pyr,H‐edt²⁻=pyren‐1‐yl‐ethylene‐1,2‐dithiolato). The intense electrochromic NIR absorption (λ_max=1432 nm; ε=13000 M ⁻¹ cm⁻¹ in CH₂Cl₂) and the potential‐controlled visible emission in the range 400–500 nm, the energy of which depends on the charge of the complex, were interpreted on the grounds of time‐dependent DFT calculations carried out on the cis and trans isomers of 1 , 1 ⁻, and 1 ²⁻. In addition, to evaluate the nonlinear optical properties of 1 ^x− (x=0, 1), first static hyperpolarizability values β_tot were calculated (β_tot=78×10⁻³⁰ and 212×10⁻³⁰ esu for the cis isomer of 1 ⁻ and 1 , respectively) and compared to those of differently substituted [Au(Ar,H‐edt)₂]^x− gold dithiolenes [Ar=naphth‐2‐yl ( 2 ), phenyl ( 3 ); x=0, 1].     

聚醚醚酮复合材料表面生物活性涂层的制备与性能

以聚醚醚酮/钡玻璃粉(PEEK-BGF)复合材料为基体, 通过硅烷偶联剂, 在复合材料表面构建具有生物活性的纳米羟基磷灰石(nHA)和甲基丙烯酸酯基的光固化树脂复合涂层. 采用扫描电子显微镜(SEM)和X射线光电子能谱(XPS)分析了材料表面形貌和元素分布, 测试了涂层与复合材料之间的粘接强度. 通过检测大鼠成骨细胞总蛋白含量和碱性磷酸酶表达水平, 评价新型光固化纳米羟基磷灰石/聚甲基丙烯酸酯(nHA/PMMA)复合涂层的生物活性. 研究结果表明, nHA填充的光固化复合材料形成粗糙的表面, 随着nHA的填充量提高, 涂层表面生物学活性得到提高.     

高比表面积Y-掺杂二氧化铈纳米颗粒和纳米棒的制备及电学性质

分别通过室温老化和高温沉降热处理成功的合成了大量均匀的Y-掺杂铈纳米颗粒和纳米棒,并对Y-掺杂铈粉末中Y的含量和形态对于固体溶液性质的影响进行了研究。结果表明,Y的掺杂大大提高了铈纳米颗粒和纳米棒的比表面积,其中30%的Y-掺杂纳米颗粒的比表面积最大,可达197 m2.g-1。此外,所制备的粉末可以很容易被烧结和硬化,而相应的电解质具有良好的电学性质,其中Y0.3Ce0.7O1.85纳米颗粒电解质在850℃时具有最大电导率(4.32 S.m-1)和最小表观活化能(0.81 eV)。     

Theoretical Studies on the One‐ and Two‐Photon Absorption Properties of Double‐bis(styryl)benzene Derivatives

Two series of bis(styryl)benzene derivatives (BSBD), namely the single‐BSBD and the double‐BSBD, were investigated. The equilibrium geometries and electronic structures were obtained by using the density functional theory B3LYP and 6‐31G basis set. In succession, the one‐ and two‐photon absorption properties of all the molecules were studied theoretically with a ZINDO‐SOS (sum‐over‐states) method in detail. It can be seen that the double‐BSBDs have larger two‐photon absorption (TPA) cross sections in the visible‐IR range than the corresponding single‐BSBDs, demonstrating that increasing the molecular dimension is a very effective method to enhance the values of the TPA cross sections. On the other hand, it can be also noticed that the values of the TPA cross sections are correlative with the ability of donating (accepting) electrons of the terminal substituent groups R [N(CH₃)₂, CH₃, H and CF₃] in these molecules. That is, the intramolecular charge transfer is also a factor for the enhancement of the TPA efficiency. To sum up, the idea of increasing the molecular dimension to enhance the TPA cross section value is a helpful direction to explore better TPA materials for practical applications. And the double‐BSBD molecules are promising TPA materials for the further investigation from the standpoint of the high transparency and the larger TPA cross sections.     

Electroconductive Hydrogels: Electrical and Electrochemical Properties of Polypyrrole‐Poly(HEMA) Composites

Composites of inherently conductive polypyrrole (PPy) within highly hydrophilic poly(2‐hydroxyethyl methacrylate)‐based hydrogels (p(HEMA)) have been fabricated and their electrochemical properties investigated. The electrochemical characteristics observed by cyclic voltammetry suggest less facile reduction of PPy within the composite hydrogel compared to electropolymerized PPy, as shown by the shift in the reduction peak potential from ?472 mV for electropolymerized polypyrrole to ?636 mV for the electroconductive composite gel. The network impedance magnitude for the electroconductive hydrogel remains quite low, ca. 100 Ω, even upon approach to DC, over all frequencies and at all offset potentials suggesting retained electronic (bipolaronic) conductivity within the composite. In contrast, sustained application of +0.7 V (vs. Ag/AgCl, 3 M Cl^?) for typically 100 min. (conditioning) to reduce the background amperometric current to <1.0 μA, resulted in complete loss of electroactivity. Nyquist plots suggest that sustained application of such a modest potential to the composite hydrogel results in impedance characteristics that resembles p(HEMA) without evidence of the conducting polymer component. PPy composite gels supported a larger ferrocene monocarboxylate diffusivity (D_appt=7.97×10^?5 cm² s^?1) compared to electropolymerized PPy (D_appt=5.56×10^?5 cm² s^?1), however a marked reduction in diffusivity (D_appt=1.01×10^?5 cm² s^?1) was observed with the conditioned hydrogel composite. Cyclic voltammograms in buffer containing H₂O₂ showed an absence of redox peaks for electrodes coated with PPy‐containing membranes, suggesting possible chemical oxidation of polypyrrole by the oxidant     

Preparation,Characterization, and Bioelectrocatalytic Properties of Hemoglobin Incorporated Multiwalled Carbon Nanotubes‐Poly‐L‐lysine Composite Film Modified Electrodes Towards Bromate

The present work describes preparation of hemoglobin‐incorporated multiwalled carbon nanotubes‐poly‐L ‐lysine (MWCNT‐PLL)/Hb) composite modified electrode film modified glassy carbon electrode (GCE) and its electrocatalytic behavior towards reduction of bromate ( ) in 0.1 M acetate buffer (pH 5.6). The modified electrode has been successfully fabricated by immobilizing hemoglobin on MWCNT dispersed in poly‐L ‐lysine. The surface morphologies of MWCNT, PLL and Hb were characterized using atomic force microscopy (AFM). The voltammetric features suggested that the charge transport through the film was fast and the electrochemical behavior resembles that of surface‐confined redox species. Cyclic voltammetry was used to investigate the electrocatalytic behavior of the modified electrode towards bromate and was compared with that of the CNT‐modified as well as bare electrode. The analytical determination of bromate has been carried out in stirred solution at an optimized potential with a sensitivity of 7.56 μA mM^?1 and the calibration curve was linear between 1.5×0^?5 to 6.0×0^?3 M.     

聚酰亚胺硅氧烷/聚酰亚胺两面异性复合膜的制备及性能研究

以氨丙基封端的聚二甲基硅氧烷(PDMS)、 4,4'-二氨基二苯醚(4,4'-ODA)和3,4,3',4'-联苯四酸二酐(s-BPDA)为原料, 合成了聚酰胺酸硅氧烷嵌段共聚物. 将此嵌段共聚物和聚酰胺酸(s-BPDA/4,4'-ODA)共混, 通过控制制膜条件, 利用各组分在不同溶剂中的溶解度的差别, 使聚酰亚胺硅氧烷富集在膜的上表面. 因为两相在结构和性质上的相似性, 当聚酰胺酸硅氧烷和聚酰胺酸混合时, 具有很好的相容性, 消除了两相间的界面, 从而制备了优异的聚酰亚胺硅氧烷/聚酰亚胺两面异性的复合膜材料. 利用X射线光电子能谱(XPS)和水滴接触角对此复合膜进行了表征, 证明了此复合膜的两面异性, 并对此复合膜进行了热性能和机械性能研究, 发现此薄膜保持了聚酰亚胺优异的性能.     

Influence of Dopant Loading on the Photo‐ and Electrochemical Properties of (N,O)‐Co‐doped Graphene.

A series of (N, O)‐co‐doped graphenes with different N and O loadings are prepared by the pyrolysis of natural chitosan. When the percentage of dopant increases, the conduction‐band potential and charge‐separation quantum yield increase, whereas the charge‐separation lifetime decreases.     

Zone‐Drawn Poly(p‐phenylene) Films. Effects of Molecular Orientation on Electrical and Mechanical Properties

The electrochemically synthesized poly(p‐phenylene) film could be zone drawn by a factor of 1.57, where the orientation function (f) increased with the draw ratio (λ), regardless of the heater temperature (T_h) or applied tension (σ), and reached 0.428 for the resulting film. The electrical conductivity in the drawing direction rose with f but decreased as T_h became higher due to dedoping that occurred simultaneously with drawing. Young's modulus and tensile strength significantly increased to 4.5 GPa and 155 MPa by zone drawing from 1.1 GPa and 79 MPa of the as‐synthesized film.