A soluble and multichromic conducting polythiophene derivative

A new soluble polythiophene derivative was synthesized by both chemical and electrochemical oxidative polymerization of 1-4-nitrophenyl-2,5-di(2-thienyl)-1H-pyrrole (SNSNO₂). Chemical method produces a polymer which is completely soluble in organic solvents. The structures of both the monomer and the soluble polymer were elucidated by ¹H and ¹³C-NMR and FTIR. The average molecular weight has been determined by GPC to be Mn = 6.3 × 10³ for the chemically synthesized polymer. P(SNSNO₂) was also synthesized via potentiostatic electrochemical polymerization. Characterizations of the resulting polymer were performed by cyclic voltammetry CV, FTIR and UV-Vis spectroscopy. Four-probe technique was used to measure the conductivities of the samples. Moreover, the spectroelectrochemical and electrochromic properties of the polymer film were investigated. In addition, dual type polymer electrochromic devices ECDs based on P(SNSNO₂) with poly3,4-ethylenedioxythiophene (PEDOT) were constructed. Spectroelectrochemistry, electrochromic switching and open circuit stability of the devices were studied. They were found to have good switching times, reasonable contrasts and optical memories.     

Dependence of Performance of Organic Light-emitting Devices on Sheet Resistance of Indium-tin-oxide Anodes

IntroductionIndium-tin-oxide(ITO) has been widely used asthe anode material in organic light-emitting devices(OLEDs) because of its high transmittance in the visi-ble region and low electrical resistivity. In the pastyears, many investigations focused on …     

Microfabricated bioreactor chips for immobilised enzyme assays

A microfabricated device is reported that has been designed to permit the in situ packing of a section of channel with enzyme immobilised onto controlled pore glass (CPG). It is fabricated from glass and polydimethylsiloxane and to prevent dead volumes, has dedicated channels for packing the reactor. The device has the advantage of being simple in design, the flow through enzyme reactor channel being simply a widened section of the analyte channel. The system is suitable for both hydrodynamic and electro-osmotic pumping, and is designed such that when the packing is exhausted it can be repacked. Controlled pore glass provides a reproducible none swelling, high porosity medium onto which the enzyme could be immobilised. The large particle size meant that it was vital to optimise the immobilisation procedure in order to achieve acceptable enzyme activity. The microfabricated device was developed with two enzymes of different molecular masses; alkaline phosphatase and xanthine oxidase. The pore size of the CPG was found to be very important for xanthine oxidase, where the 697 Å pore size (120-200 mesh) CPG was found to give the highest activity (18-20% activity retained after immobilisation). The microfabricated device was used for the assay of p-nitrophenyl phosphate and hypoxanthine with spectrophotometric detection at 405 and 470 nm, respectively. The limits of detection were 5 and 8 μM, respectively.     

Synthesis and Characterization of Fluoro- and Chloro- bimetallic Alkoxides as Precursors for Luminescent Metal Oxide Materials via Sol-Gel Technique

Heterobimetallic alkoxides are broadly recognized as versatile precursors for luminescence materials, and efforts are being made to develop novel routes by applying the concept of geometrical molecular design, for their synthesis and to design a single source precursor suited to photoluminescent materials. Novel and new series of bimetallic alkoxides has been prepared by metathesis route. They exhibit a lower sensitivity towards hydrolysis and so they are easier to handle as compared to other alkoxides. All the compounds were characterized by elemental analysis, FT-IR and multinuclear NMR spectroscopies. FT-IR revealed that the molecular structure of these metal alkoxides was retained to a large extent in 4 ： 1 halogenated alcohol-benzene solution. The heteronuclear NMR spectroscopy provided useful information about chemical shifts for better understanding the likely structure based on interactions with their coordinate metals. The mass spectra show similar types of fragmentation pattern. SEM-EDS analyses showed consistency with the formulation. XRD patterns show an enhanced homogeneity at high temperature. TGA measurements show that thermal decomposition occured in steps that depended entirely on the chemical compositions and the synthesis routes. SEM observation reveals that the morphology and particle size strongly depend on synthesis routes for their precursors.     

Organosoluble and transparent polyimides derived from alicyclic dianhydride and aromatic diamines

Organosoluble polyimides were synthesized with the alicyclic dianhydride 1,8‐dimethylbicyclo[2,2,2]oct‐7‐ene‐2,3,5,6‐tetracarboxylic dianhydride and aromatic diamines. The polyimides possessed good solubility both in strong dipolar solvents and in common solvents; the thermal decomposition temperature of the polyimides exceeded 420 °C. Strong and flexible films of the polyimides, with the cutoff of ultraviolet–visible absorption lower than 310–320 nm, exhibited good features as the alignment layers for nematic liquid crystals with pretilt angles of 1.5–2.9°. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 110–119, 2002     

二维配位聚合物[Zn(PDC)(phen)]n的合成、晶体结构及荧光性质

合成了锌(II)与3,4-吡啶二羧酸和1,10-邻菲啰啉形成的配位聚合物[Zn(PDC)(phen)]_n (1) (H₂PDC＝3,4-吡啶二羧酸, phen＝1,10-邻菲啰啉), 对其进行了元素分析、红外光谱和X射线单晶衍射表征, 测定了晶体结构. 该聚合物属单斜晶系, P2(1)/n空间群, a＝0.77136 nm, b＝1.9757(4) nm, c＝1.0680(2) nm, β＝95.36(3)°, V＝1.6205(6) nm³, Z＝4, D_c＝1.683 Mg/m³, M_r＝410.68, F(000)＝832, μ＝1.55 mm^－1, 最终偏离因子R₁＝0.0608, wR₂＝0.0967. 该化合物中Zn原子与来自两个PDC的三个羧基氧原子, 另外一个PDC的吡啶氮原子, 以及phen的两个氮原子配位, 形成的ZnN₃O₃八面体通过PDC桥联形成二维层状网络结构. 此外还研究了该聚合物的热性质和荧光性质.     

可移动式微量氧分析仪检定装置研制

研制一种新型可移动式微量氧分析仪检定装置。该装置由标准气体、零点气、脱氧纯化器、减压阀、调节阀、4通阀、5通阀、不锈钢管路、流量控制系统、移动平台等组成。该装置气密性好,15 min内可将装置内氧气浓度由20.9%降至不大于0.1μmol/mol,对于0~10μmol/mol的微量氧分析仪检定结果的扩展不确定度为Urel=1.7%FS(k=2)。该装置满足气体标准物质的连续切换和在线检定的需要,检定时间短,结果准确可靠,可为在线式和非在线式微量氧分析仪的量值溯源提供有效保障。     

Creation of highly functional thin films using electrochemical nanotechnology

This overview describes the results of our recent study of the application of electrochemical nanotechnology to the fabrication of magnetic recording materials, interconnects in ultra-large-scale integrated (ULSI) devices, energy storage materials, and on-chip biosensors. It is important to note that electrochemical processes play significant roles in developing and fabrication such sophisticated materials and devices. In the field of magnetic recording, electrodeposition methods for preparing CoNiFe and CoFe soft magnetic thin films with a high saturation magnetic flux density were newly developed, and the significant issues for obtaining those films are highlighted. In the area of ULSI interconnects, we developed a technique using a self-assembled monolayer (SAM) for direct bonding of the interconnect layer to SiO2, and proposed a novel electroless deposition method for fabricating a diffusion barrier layer. In the field of batteries, electrodeposited SnNi alloy was proposed as a future anode material for Li batteries, and electrochemical MEMS processes were shown to be useful for fabricating micro-sized direct methanol fuel cells (DMFCs) as portable batteries for electronics applications. In the area of chemical sensors, we developed a new process for fabricating field effect transistors (FETs) modified with SAMs for on-chip biosensing applications.     

Crystal Structure, Thermal Stability and Luminescence of Coordination Polymer [Cd（BBP）（p-PDOA）]n

Hydrothermal reaction of Cd（NO3）2·4H2O with bbp and p-PDOAH2 at 140 ℃ yielded a novel 1D cadmium（Ⅱ） coordination polymer, [Cd（bbp）（p-PDOA）]n （bbp=2,6-bis（benzimidazol-2-yl）pyridine, p-PDOA=p-phenylenedioxydiacetate dianion）, in which CdN3O4 pentagonal bipyramids were linked by p-PDOA ligands in a bis-bidentate mode to construct a zigzag chain with the adjacent Cd…Cd distance of 1.14（1） nm, There exists a 2D supramolecular network linked by π-π stacking with a face-to-face distance of 0.35（1） nm between the 2,6-bis（benzimidazol-2-yl） pyridine ligands and hydrogen-bonding interactions （0.27（4） nm）. A 3D supramolecular network was further constructed by these non-covalent interactions between the zippers. The TG/DTG showed that its chain skeleton was thermally stable up to 389 ℃ and the blue fluorescent emission of the complex was determined at 428 nm in a solid state with its long decay lifetime of 7.24 ns.     

Microdevices for manipulation and accumulation of micro- and nanoparticles by dielectrophoresis

Microfluidic devices with three-dimensional (3-D) arrays of microelectrodes embedded in microchannels have been developed to study dielectrophoretic forces acting on synthetic micro- and nanoparticles. In particular, so-called deflector structures were used to separate particles according to their size and to enable accumulation of a fraction of interest into a small sample volume for further analysis. Particle velocity within the microchannels was measured by video microscopy and the hydrodynamic friction forces exerted on deflected particles were determined according to Stokes law. These results lead to an absolute measure of the dielectrophoretic forces and allowed for a quantitative test of the underlying theory. In summary, the influence of channel height, particle size, buffer composition, electric field, strength and frequency on the dielectrophoretic force and the effectiveness of dielectrophoretic deflection structures were determined. For this purpose, microfluidic devices have been developed comprising pairs of electrodes extending into fluid channels on both top and bottom side of the microfluidic channels. Electrodes were aligned under angles varying from 0 to 75 degrees with respect to the direction of flow. Devices with channel height varying between 5 and 50 microm were manufactured. Fabrication involved a dedicated bonding technology using a mask aligner and UV-curing adhesive. Particles with radius ranging from 250 nm to 12 microm were injected into the channels using aqueous buffer solutions.