Synthesis and Electrochemical Proprieties of Novel Unsymmetrical Bis-Tetrathiafulvalenes and Electrical Conductivity of Their Charge Transfer Complexes with Tetracyanoquinodimethane (TCNQ)

The synthesis and properties of a series of bis-tetrathiafulvalenes (bis-TTFs) containing nitrophenyl, aminophenyl or dimethylaminophenyl is reported. The synthesis was carried out by using routes involving Wittig-type, cross-coupling, reduction and alkylation reactions. The electron donor ability of these new compounds has been measured by cyclic voltammetry (CV). Charge transfer complexes with tetracyanoquinodimethane (TCNQ) were prepared by chemical redox reactions. The complexes have been proven to give conducting materials.     

Synthesis, Characterization, and Electrical Conductivity of Oligo[aromatic diimidoselenium(IV)]

Oligo[aromatic diimidoselenium] (PADIS) is prepared from the reaction of the disubstituted aromatic compounds, namely, 1,4-phenylenediamine, 4,4-thiodianiline, 1,1-biphenylene-4,4-diamine, and 2,2-dithiodianiline, with selenium dioxide in refluxing absolute ethanol. The four materials are investigated by elemental analysis, electronic spectra, Fourier Transform-infrared spectroscopy, and [¹H]NMR spectroscopy. The DC electrical conductivity variation with temperature in the range 300–500 K of the materials after annealing for 24 h at 100°C and after doping with 10% I₂ is determined for comparison.     

Synthesis,Characterization and Electrical Conductivity of Polyesters Containing Azomethine Linkages

Abstract

The synthesis and characterization of some polyesters containing azomethine linkages are reported here. The electrical conductivity of these polyesters is measured and the results are explained with simple Pariser-Parr-Pople calculations. The polymers are doped with Ag and the electrical conductivity of most of the doped polymers is found to register significant increase. Attempts are made to explain this increase in electrical conductivity.     

Synthesis,Characterization, and Electrical Properties of New Crosslinked Conjugated Polymer Based on Acetyl Acetone Moiety

A new crosslinked conjugated polymer has been prepared by condensation of acetyl acetone with terephthalaldehyde using hydrogen chlorides as a catalyst and ethanol as a solvent. The resulting polymer was investigated by spectroscopic methods (IR,¹H-NMR). The inherent viscosity was found to be about 0.92 dl/g. The crosslinked conjugated polymer is semicrystalline and partially soluble in most common organic solvents but freely soluble in the aprotic solvent. The synthesized polymer was evaluated by TGA analyses and has been found to be thermally stable. The morphology of the dry polymer was examined by scanning electron microscope, and the electrical conductivity was found to be in the range of 10^?6 Ω^?1 m^?1 at room temperature and above up to 44°C.     

Characterization,Electrical Conductivity and Electrochemical Performance of Polyaniline-LiClO4-CuO Nano Composite for Energy Storage Applications

Polyaniline (PANI), PANI/LiClO₄ composite with 5% & 10% of salt and PANI/LiClO₄/CuO NPs (PLC) nanocomposite were synthesized by chemical method and characterized them with help of fourier transform infrared spectrometer (FT-IR) spectrometer to investigate the chemical interaction between salt and confirmed the composite formation. Field emission scanning electron microscope (FESEM) is used to study the morphological changes in the composite due to effect of salt and formation of long fiber structures. provide the conducting path between the polymer matrix and the Li⁺ ions helps to increase conductivity. The absorbance study reveals shifting of absorption wavelength towards higher end with increasing salt content in PANI is attributed to the π→π* electron transition in the benzenoid and quinoid rings. The optical band gap (E_g) found decreasing from 2.88 to 2.35 eV for 10% of salt and 2% CuO nano NPs due to forming delocalized charges in host polymer. The dielectric parameters, and AC conductivity against frequency at different temperatures were studied. The PANI/LiClO₄ composites are electrochemically stable upto 1000^th cycle with 213.08 F/g specific capacitance at 3mA/g current density for10% of salt.     

Formation, Characterization and Electrical Conductivity of Polycarbosilazane-Cu(II), -Ni(II) and -Cr(III) Chloride Metallopolymers

A series of transition metal-polycarbosilazane complexes have been prepared by the reaction of poly(N,N-bis(dimethylsilyl)ethylenediamine), [–Si(CH₃)₂NHCH₂CH₂NH–] _n , with Cu(II), Ni(II), and Cr(III) chloride. The resulting complexes were characterized by infrared (FT-IR) and UV-visible spectroscopy, magnetic susceptibility measurements, thermogravimetric analysis (TGA), and powder X-ray diffraction (XRD). The average chain-chain spacing in these materials were estimated from XRD data and found to be 6.88, 7.91, 7.09, and 6.33 Å in metal-free, Cu(II)-, Ni(II)-, and Cr(III)-containing polycarbosilazanes, respectively. DC electrical conductivity measurements showed that all these metal-polycarbosilazane complexes exhibit semiconductor behavior while the metal-free matrix is an insulator.     

Synthesis,Characterization, and Conducting Properties of Poly(thiourea azomethines)

Three new polyazomethines having phenylthiourea groups were synthesized through solution polycondensation of terephthalaldehyde with 4,4′-bis(thiourea)biphenyl ether, 4,4′-bis(thiourea)biphenylmethane, and 4,4′-bis(thiourea)biphenyl sulphone. For comparison purposes, simple polyazomethines were prepared by the polycondensation of terephthalaldehyde with 4,4′-diaminodiphenyl ether, 4,4′-diaminodiphenylmethane, and 4,4′-diaminodiphenyl sulphone. Poly(imine)s having phenylthiourea groups were characterized through IR and ¹H-NMR spectroscopic methods and the thermal stability of the polymers were evaluated through TGA analysis. Conductivity of polyaniline synthesized in aqueous p-toluenesulfonic acid was found to be 3.83 Scm^?1. The conductivity of the polymeric blends with polyaniline dopped with p-toluenesulfonic acid and HCl (20% by weight) were found to be in the range 0.16 × 10^?3 ? 5.7 × 10^?3 Scm^?1.     

丁腈橡胶导电性与温度特性的研究

对乙炔炭黑填充丁腈橡胶（ＮＢＲ）的导电性及其与温度的关系进行了研究,分析了丁腈橡胶的电阻率与乙炔炭黑（简称：ＣＢ）填充量的关系,并对环境温度变化时电阻率的变化规律提出了相应的关系式,同时对导电丁腈橡胶的通电时间与表面温度的关系进行了研究与测定。     

Synthesis,Thermal Properties and Electrical Conductivity of Na-Sialate Geopolymer

This work aims to study the thermal behavior of basic-geopolymers derived from metakaolin (clay). The geopolymers were characterized by different techniques: thermal analysis (DTA, TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and impedance spectroscopy. Some physicochemical properties of the products were also determined: the phases obtained after geopolymer heat treatment and their electrical properties. The results obtained after drying and heat treatment showed that the products kept their initial shapes, but revealed variable colors depending on the temperatures at which they were treated. The products obtained are amorphous between 300 up to 600 °C with peaks relating to the presence of nanocrystallites of muscovites and zeolite, thus at 900 °C it is quite amorphous but only contains nanocrystallites of muscovites. From the temperature of 950 °C, we notice that the geopolymer has been transformed into a crystalline compound predominated by the Nepheline (NaAlSiO₄) with the presence of a crystalline phase by minor peaks of Muscovite, this crystalline character has been increased at 1100 °C to obtain a whole phase crystalline of a Nepheline. The treatment of this geopolymer for one hour at 1200 °C shows an amorphous phase again corresponding to corundum (α-Al₂O₃). This indicates that the dissolution of the grains by the liquid phase induces the conversion of the material structure from sialate [–Si–O–Al–O] to sialate siloxo [–Si–O–Al–O–Si–O–] and the formation of a new crystalline phase (α-Al₂O₃). This development of sialate to sialate-siloxo was confirmed by IR spectroscopy. As mentioned above, from 300 to 900 °C, Na-sialate geopolymer exhibits the same disorder structure of nepheline. The crystal structure of nepheline is characterized by layers of six-membered tetrahedral rings of exclusively oval conformation. The rings are built by Regularly alternating tetrahedral AlO₄ and SiO₄. Stacking the layer’s parallel to the c axis gives a three-dimensional network containing channels occupied by Na cations. This topology favors easy movement of Na⁺ ions throughout the structure. For this reason, ionic migration in nepheline is widely reported. The refinement of Na-Sialate geopolymer at room temperature gives bulk high ionic conductivity of about 5 × 10^?5 S cm^?1 and this is due to the probable joint contribution of H⁺ and Na⁺ ions. Above 200 °C, Na⁺ seems to remain the only charge carrier with a low activation energy of about Ea?=?0.26 eV. At higher temperatures, the characteristic frequencies become so close that it is impossible to distinguish the contributions. A total resistance comprising both grain and grain boundaries contribution is then determined.

     

Novel Poly(linolenic acid) Graft Copolymers: Synthesis,Characterization and Electrical Properties

A poly(linolenic acid)‐g‐poly(tert‐butyl acrylate) graft copolymer was synthesized from polymeric linolenic acid peroxide possessing peroxide groups in the main chain by free radical polymerization of tert‐butyl acrylate. Graft copolymers having structures of poly(linolenic acid)‐g‐poly(caprolactone)‐g‐poly(tert‐butyl acrylate) were synthesized from polymeric linolenic acid, possessing peroxide groups on the main chain by the combination of free radical polymerization of tert‐butyl acrylate and ring‐opening polymerization of ε‐caprolactone in one‐pot. The obtained graft copolymers were characterized by proton nuclear magnetic resonance, gel permeation chromatography, thermal gravimetric analysis, differential scanning calorimetry, and scanning electron microscopy techniques. Furthermore, Au/n‐Si diodes were fabricated with and without poly(linolenic acid)‐g‐poly(caprolactone)‐g‐poly(tert‐butyl acrylate)‐4 to form a new interfacial polymeric layer for the purpose of investigating this polymer's conformity in electronic applications. Some main electrical characteristics of these diodes were investigated using experimental current–voltage measurements in the dark and at room temperature.     

Molecular Sieve Materials: Their Synthesis,Properties, and Characterizations

An overview of the history and development of molecular sieve materials since their discovery and commercialization is presented. The evolutionary changes in their composition, sorptive and catalytic properties, surface selectivity, and stability characteristics are emphasized.     

Enhancement of Electrical Conductivity of Polyethylene Terephthalate (PET) Fabrics via Ionic Liquids

In this study, polyethylene terephtalate (PET) fabrics were treated with two types of ionic liquids, 1-ethyl-2,3-dimethylimidazolium ethyl sulfate (EIL) and methyl-tri-n-butylammonium methyl sulfate (BIL), resulting in noticeably better long-term electrical conductivity of treated PET fabrics. Thermal conductivity, thermal stability, surface morphology and chemical structure were also explored. The effects of concentration of EIL (2, 6, 10 w/v %) and BIL (10, 15, 20 w/v %) ionic liquids were discussed. With the given set up, surface resistivities of the PET fabrics decreased with treatment application of the ionic liquids. Besides, BIL treatment provided higher electrical conductivity as compared with EIL. Moreover, surface resistivity presented diminishing tendency with increasing the concentration. It is also found that thermal degradation temperatures of the PET fabrics decreased with ionic liquids treatment. A coating layer was observable on surface of the fabric and in the gaps of the yarns with the ionic liquids treatment. This work provided a novel method for obtaining enhanced electrically conductive PET fabrics for textile industry.     

Mechanical Properties and Electrical Conductivity of TiN-Al_2O_3 Composites

TIN-Al2O3 composite powders with different TiN contents (0,10 vol%,20 vol%,30 vol% and 40 vol%) were prepared with micrometer TiN and α-Al2O3 powder (their purities were 99%) as starting materials by wet ball milling for 5 h.TiN-Al2O3 com-posite were then prepared by pressing the above composite powders,drying at 200 ℃ for 12 h and firing at 1 800 ℃ for 3 h in nitrogen atmosphere in hot-pressing furnace.The influences of TiN content on mechanical properties and electrical conductivity of TiN-Al2O3 com-posites were studied.The results showed that the me-chanical properties of the composite increased with TiN content increasing,while the resistivity of composites de-creased.A composite with 40% TiN had 498 MPa ben-ding strength,4.285 MPa·m1/2 fracture toughness,1.34×10-3 Ω·cm resistivity.The SEM analysis showed that the fine TiN crystals distributed among the crystal boundary of Al2O3 matrix.They bonded together forming a net-like structure which played a role of re-straining Al2O3 grains from growing up,toughening and strengthening,so the mechanical properties of TIN -Al2O3 composite were enhanced.     

Electrochemical Synthesis of Poly(3,4-ethylenedioxythiophene) on Steel Electrodes: Properties and Characterization

Electrodeposition of poly(3,4-ethylenedioxythiophene) by electrochemical polymerization of 3,4-ethylenedioxythiophene has been performed on steel electrodes rather than on the typically used inert electrodes (Pt, Au, graphite carbon). The polymer was generated by cyclic voltammetry, chronopotentiometry and chronoamperometry from a 10 mM monomer solution in acetonitrile with 0.1 M LiClO₄. Elemental analysis of the generated polymer indicated that the monomeric units support 0.54 positive charges balanced with CIO₄ ¹⁴⁻ counterions. Electrochemical, electrical and structural properties of the prepared material have been characterized. The good adherence of films combined with its excellent properties indicate that poly(3,4-ethylenedioxythiophene) can be a suitable material for anticorrosion applications.     

非对称紫精化合物的合成表征及电致变色性能

该文以4,4′-联吡啶分别与溴代正辛烷、氯化苄反应,再与对氯甲基苯乙烯反应合成了两个非对称含有不饱和双键的紫精化合物,二氯化1-苄基-1′-[4-(乙烯基)苄基]-4,4′-联吡啶盐和氯化溴化1-辛基-1′-[4-(乙烯基)苄基]-4,4′-联吡啶盐,收率超过80%。运用红外光谱,核磁共振氢谱表征其结构,并采用循环伏安法研究了它们的电致变色性能。结果表明,在0～-1V区间内,两个化合物在无色和紫红色间循环变化,具有稳定的电致变色性能,可望用以制作实用的电致变色器件。     

MWCNTs/PS复合材料导电性能及导电行为研究

多壁碳纳米管(MWCNTs)与聚苯乙烯(PS)熔融共混,制备试样,部分试样进行热处理。通过导电性能的测试研究了不同测试温度对MWCNTs/PS非结晶复合材料电性能及其导电行为的影响;通过SEM观察了该复合材料的表面形貌。研究结果表明:随着MWCNTs加入量的增加,MWCNTs/PS的体积电阻率(ρ)呈现下降趋势;当MWCNTs加入量达到8.0%,复合材料的ρ降到102数量级;120℃热处理后MWCNTs(10.0%)/PS复合材料的ρ比未经热处理的ρ下降近1个数量级;MWCNTs(10.0%)/PS 1-3型复合材料的PTC行为不明显,但5.0%MWCNTs/PS1-3型复合材料的PTC效应明显,在150℃以后,出现NTC效应。     

二二甲亚砜合硫氰酸镉（DSTC）晶体的合成、结构、表征与晶体生长

合成了金属有机配合物晶体二二甲亚砜合硫氰酸镉Cd(SCN) 2 (C2 H6 OS) 2 (简称DSTC)。用X射线四圆衍射方法确定了此化合物的晶体结构。用元素分析、红外光谱对其进行了化学表征。首次在DMSO/水的溶剂中 ,生长出尺寸为 3 5mm× 12mm× 11mm透明单晶。     

微粒的导电性对复合镀层结构与性能的影响

在复合电沉积过程中辅助施加超声波搅拌,制备出Ni-Al和Ni-Al2O3两种复合镀层。借助扫描电镜、X射线衍射仪、显微硬度计和摩擦磨损试验机研究了微粒的导电性对复合镀层形貌、相结构及性能的影响。结果表明:微粒的导电性对复合镀层的形貌、相结构和显微硬度均有一定影响,但对耐磨性的影响不明显;添加惰性微粒有利于获得形貌良好、结构致密、显微硬度较高的复合镀层。     

Characterization and Electrical Properties of Poly(aniline-co-2,4-dimethoxyaniline) Nanostructures Prepared by Interfacial Polymerization

Copolymer nanofibers of aniline and 2,4-dimethoxyaniline were chemically synthesized in various molar ratios of the comonomers by aqueous/organic phase interfacial oxidative polymerization in the presence of acid dopant. UV–visible spectroscopy, FT-IR, ¹H NMR measurements, and TGA were used to confirm the molecular structure of the doped copolymers. Morphology of synthesized copolymer nanostructures was investigated using transmission electron microscope, which indicate the formation of one-dimensional (1D) nanofibers with average diameter of 4–10 nm. The conductivity of the nanofibers increased significantly with increased proportion of aniline in the copolymer.     

硼氟二吡咯亚甲基衍生物的合成、表征及光物理性质的研究

成功合成了中位为2-喹啉噻吩基硼氟二吡咯亚甲基和对葡萄糖四乙酸酯苯基的化合物4,4-二氟-8-[5'-(2-喹啉基)-2-噻吩基]-1,3,5,7-四甲基-4-硼-3a,4a-二氮杂-S-引达省和4,4-二氟-8-[4'-(2,3,4,6-O-四乙酰基-α-D-吡喃葡萄糖-1-氧基)苯基]-1,3,5,7-四甲基-4-硼-3a,4a-二氮杂-S-引达省,通过核磁进行表征。研究了这两个化合物在二氯甲烷中的紫外可见吸收光谱和荧光光谱,研究了化合物在薄膜和固体状态下的吸收光谱和荧光光谱,同时通过研究电化学性质得到化合物的HOMO和LUMO轨道。