Electrosynthesis and characterization of a conductive polythiophene deriving from a terthiophene monomer

The electrochemical polymerization of the 3,3″-di[(S)-(+)-2-methylbutyl]-2,2′:5′,2″-terthiophene (DMBTT) monomer was carried out potentiodynamically on indium tin oxide (ITO), Pt or glassy carbon (GC) electrodes in anhydrous CH₃CN with TBAPF₆ as supporting electrolyte. Films with good adhesion were obtained for all the tested substrates and they were characterized by various analytical techniques including UV–Vis–NIR absorption spectroscopy, cyclic voltammetry (CV), scanning electron microscopy (SEM), and gel permeation chromatography (GPC). The most outstanding properties of the electrochemically synthesized polymer were compared with those of the same polymer obtained by a chemical method. The film obtained on ITO displayed a reversible electrochromic behavior under potential switching between −0.50 and +1.00 V vs. SCE.     

聚噻吩衍生物的合成及改性研究

首先利用Kumada反应合成了3种噻吩单体,即3-丁基噻吩、3-苯基噻吩和3-十六烷基噻吩;然后采用三氯化铁(FeCl3)氧化法合成了对应的3种聚噻吩;最后将3种聚噻吩与富勒烯(C60)进行溶液复合,得到了光电性能和溶解性能俱佳的聚噻吩/C60复合材料。采用红外光谱(FT-IR)、扫描电镜(SEM)、热失重分析(TGA)和伏安循环(CV)曲线等方法对聚噻吩及其复合材料的化学结构、溶解性能、热性能和电性能等进行了表征,并探讨了不同噻吩取代基对聚合物分子链共轭效应的影响规律。结果表明:3种改性聚噻吩具有良好的溶解性、耐热性和导电性;C60在3种改性聚噻吩中分散性良好,并使聚噻吩的电导率提高了10个数量级左右,其中聚3-十六烷基噻吩/C60复合材料的电化学能隙为1.70eV。     

Electrosynthesis and impedance studies on zinc selenide

Electrochemical impedance measurements have been used to characterize zinc selenide films prepared by electrochemical co-deposition at a platinum rotating disk electrode. Estimations of capacitance and polarization resistance of variously prepared electrodeposits have been carried out to determine charge carrier density and corrosion rates.     

基于聚噻吩及其衍生物电致变色材料的研究进展

总结了聚噻吩衍生物的合成方法,介绍了聚噻吩衍生物电致变色器件中的关键构成和聚噻吩衍生物的电致变色应用现状,指出了聚噻吩衍生物未来发展前景。     

A solid-state electrochromic device based on complementary polypyrrole/polythiophene derivatives and an elastomeric electrolyte

A device was assembled using optically transparent glass electrodes and combining two complementary electrochromic polymeric materials, poly(4,4-dipentoxy-2,2-bithiophene) and poly(N,N-dimethyl-2,2-bipyrrole). As electrolyte we used an ionically conductive polymer; poly(epichlorohydrin-co-ethylene oxide) containing a lithium salt. The optical contrast in the visible/near infrared region, stability to repeated redox cycles and electrochromic efficiency are reported and discussed.     

Bulky side-chain density effect on the photophysical, electrochemical and photovoltaic properties of polythiophene derivatives

Low band-gap polythiophene (PT) derivatives, with bulky conjugated side-chains composed of the triphenylamine, thiophene, and vinylene groups (TPATh), are synthesized. The copolymers, synthesized by Grignard metathesis and Stille coupling with different copolymer configurations and side-chain densities, are regioregular-TPATh-PT (rr-TPATh-PT) and random-TPATh-PT (r-TPATh-PT), respectively. The incorporation of bulky conjugated moiety curtails the effective conjugation length in the main chain; thus, low HOMO levels are obtained for the copolymers. Moreover, r-TPATh-PT with less bulky side-chain content exhibits a better conjugation along the polymer backbone than rr-TPATh-PT. Higher absorption intensity in the vision region is observed for r-TPATh-PT in comparison with rr-TPATh-PT. In addition, polymer solar cells (PSCs) are fabricated based on an interpenetrating network of PT derivatives as the electron donor and the fullerene derivatives (PC₆₁BM and PC₇₁BM) as the electron acceptors. Better compatibility is observed for the r-TPATh-PT/PC₆₁BM-blend film as compared to the rr-TPATh-PT/PC₆₁BM-blend film. Higher photovoltaic (PV) performances of the r-TPATh-PT/PC₆₁BM-based PSCs are observed in comparison with the rr-TPATh-PT/PC₆₁BM-based PSCs. The power conversion efficiency (PCE) of the PSC based on the blend of r-TPATh-PT and PC₆₁BM (w/w = 1:1) reaches 0.94% under an illumination of AM 1.5G, 100 mW cm⁻², which is almost twice that of the cell based on rr-TPATh-PT. Further improvement of PV performance is achieved for the PSC fabricated from the blend of r-TPATh-PT and fullerene derivative PC₇₁BM (w/w = 1:3), with a short-circuit current of 6.83 mA cm⁻², an open-circuit voltage of 0.71 V and a PCE of 1.75%.     

Synthesis,characterization, and studies on the solid-state crosslinking of functionalized vinyl cinnamate polymers

Functionalized vinyl cinnamate monomers were synthesized by the reaction between hydroxyethylacrylate (HEA) and substituted cinnamoyl chlorides possessing electron releasing and withdrawing functional groups like chloro, methoxy, and nitro groups at the para position of the aromatic ring. The structures of these monomers were characterized by Fourier transform infrared (FTIR), ¹H-, and ¹³C-NMR spectral techniques. The homopolymers of the synthesized monomers were obtained by the free radical solution polymerization in dimethylformamide (DMF) at 80°C for 12 h using azobisisobutyronitrile (AIBN) as a radical initiator. The sensitivity of these polymers towards light was studied by monitoring the photocrosslinking nature of the polymers by ultraviolet (UV) and FTIR techniques. The effect of the functional groups on the crosslinking efficiency was studied and compared with that of the unsubstituted polymer. The cyclobutane-type addition mechanism involved in the photocrosslinking phenomena was confirmed by the above spectral studies in the functionalized vinyl cinnamate polymers. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67: 441–448, 1998     

Glycolamide-functionalized ionic liquid: Synthesis and actinide ion extraction studies

A glycolamide-functionalized ionic liquid (G-FIL) was synthesized for the first time and was evaluated for the extraction of actinide ions such as Am³⁺, Pu⁴⁺ and UO₂²⁺ and fission product element ions such as Eu³⁺, Sr²⁺ and Cs⁺. The extraction of the trivalent metal ions was found to be exceptionally high at low acid concentrations, which rapidly decreased with increasing acidity. In view of the high viscosity of the G-FIL, the studies were carried out using its diluted solution in a commercial ionic liquid, viz. 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ([C₄mim][Tf₂N]).     

Evaluation of a functionalized copolymer as adsorbent on direct dyes removal process: Kinetics and equilibrium studies

Functionalized polymeric microbeads were investigated as adsorbent for the removal of three direct dyes from aqueous solutions. The effects of different experimental parameters, such as initial dye concentration, temperature, and solution pH on the adsorption process were investigated. The adsorption process can be conducted with very good result at normal working conditions: neutral pH and normal temperature. The maximum percentage removal obtained was 99.11% for the symmetrical disazo dye, 90.14% for asymmetrical disazo dye, and 98.53% for trisazo dye. The adsorption kinetics followed the pseudo‐second‐order equation for all three investigated dyes in all working conditions. The experimental data were fitted to Langmuir, Freundlich, Sips, and Redlich–Peterson isotherm models, and the best fit was obtained with Sips model. Thermodynamic parameters (ΔH°, ΔS°, and ΔG°) revealed that dye adsorption is an endothermic and spontaneous process. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Synthesis and characterization of polyesters based on tartaric acid derivatives

A series of aliphatic polyesters based on tartaric acid and its derivatives were synthesized starting from naturally occurring L-tartaric acid. The hydroxyl groups of the tartaric acid derivatives were first protected and the polyesters were synthesized by bulk and solution polycondensation methods. Two classes of polyesters were synthesized and characterized, the first by polycondensation of dimethyl 2,3-O-isopropylidene-l-tartrate with various alkanediols, and the second by reaction of 2,3-O-isopropylidene-l-threitol with various diacid chlorides. Acid catalyzed deprotection of isopropylidene groups gave well-defined polyesters having pendant hydroxyl functional groups regularly distributed along the polymer chain. The number average molecular weights (M_n) of the polymers were found to vary in the range of 2.3-15.7 × 10³ g mol⁻¹. Differential scanning calorimetry (DSC) analysis showed the glass transition temperatures (T_g) of the polyesters varied from −36.1 °C to 17.9 °C on varying the chain length.     

Corrosion inhibition and adsorption behavior of new Schiff base surfactant on steel in acidic environment: Experimental and theoretical studies

Synthesis, adsorption and corrosion inhibiting effect of new Schiff base surfactant named 4-hydroxy-3-(3-phenyl-allylideneamino)-benzene sulphonic acid2-[2-(2-{2-[2-(2-hydroxy-ethoxy)-ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethyl ether (abbreviated as PAAB) on mild steel in 1.0 M HCl were investigated using weight loss, and potentiodynamic polarization techniques. The results revealed that this compound inhibited the corrosion reaction in HCl environment. The results indicated that this inhibitor was adsorbed on the metal/solution interface. Theoretical study of the adsorption behavior of this compound was carried out in the framework of the semiempirical (SE) and molecular dynamics (MD).     

苯甲醛系列化合物的电合成进展

本文介绍了苯甲醛系列化合物的三种电合成方法：苯环上丙烯基、羟基和甲基的阳极氧化,苯环上羧基的阴极还原,苯环上甲基的阳极取代。着重对甲基的阳极氧化过程中运用的新技术及发展趋势作了评述。     

Poly(p-phenylene vinylene) derivatives with ester- and carboxy-functionalized substituents: a versatile platform towards polar functionalized conjugated polymers

A polar functionalized poly(p-phenylene vinylene) (PPV) derivative, ester containing poly(1,4-(2-(pentyloxy-5-carboxy methylester)-5-methoxyphenylene)vinylene), has been prepared via the sulfinyl precursor route. Subsequently, the carboxylic acid containing poly(1,4-(2-(5-carboxypentyloxy)-5-methoxyphenylene)vinylene) is readily obtained by the basic hydrolysis of the ester side groups. This carboxylic acid substituted polymer exhibits significantly improved optical properties as compared to previously reported similar polymers. To obtain polar functionalized PPV derivatives with more complex tailored substituents a versatile novel approach is presented based on the Mitsunobu reaction conditions via a post-polymerization functionalization of the carboxylic acid side groups. Using these reaction conditions substituents containing various ester groups, i.e. 4-nitrobenzyl, 2-nitrobenzyl, 5-(methyl)furfural and 3-N,N-dimethylamino-1-propane, have been covalently attached to the phenylene ring. Analytical data of the functionalized polymers are consistent with a quantitative functional group substitution. The results demonstrate that the employed functionalization method allows for the introduction of a large variety of polar substituents in a straightforward manner.     

电合成苯甲醛及其衍生物的研究进展

苯甲醛及其衍生物是一类非常重要的有机化工原料和反应中间体。采用电合成法制备苯甲醛及其衍生物比用传统的有机合成法有明显优势,具有环保、高效和节能等优点。综述了电合成苯甲醛及其衍生物的方法,包括直接电解氧化法、间接电氧化法、电解还原法、牺牲阳极法。讨论了间接电合成苯甲醛的影响因素,如电解媒质,电极和反应条件。最后归纳了几种重要的表征方法,包括极谱法、气相色谱法、紫外分光光度法和电位滴定法等。     

The inhibition of benzimidazole derivatives on corrosion of iron in 1 M HCl solutions

The inhibitive action of some benzimidazole derivatives namely 2-aminobenzimidazole (AB), 2-(2-pyridyl)benzimidazole (PB), 2-aminomethylbenzimidazole (MB), 2-hydroxybenzimidazole (HB) and benzimidazole (B), against the corrosion of iron (99.9999%) in solutions of hydrochloric acid has been studied using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). At inhibitor concentration range (10⁻³-10⁻² M) in 1 M acid, the results showed that these compounds suppressed both cathodic and anodic processes of iron corrosion in 1 M HCl by adsorption on the iron surface according to Langmuir adsorption isotherm. The efficiency of these inhibitors increases in the order AB>PB>MB>HB>B. Both potentiodynamic and EIS measurements reveal that these compounds inhibit the iron corrosion in 1 M HCl and that the efficiency increases with increasing of the inhibitor concentration. Data obtained from EIS were analyzed to model the corrosion inhibition process through equivalent circuit. A correlation between the highest occupied molecular orbital E_HOMO and inhibition efficiencies was sought.     

铅电极上电聚合聚苯胺及其析氧电催化性能研究

在苯胺-硫酸电解液中,采用电化学阳极氧化法在纯铅表面电沉积制备聚苯胺(PAn)膜层。探讨了苯胺电聚合过程的影响因素及其规律,并考察了所得Pb/PAn膜电极材料的析氧电催化特性。结果表明,在一定的恒电流密度下,聚苯胺的沉积量与时间成正比;与空白Pb电极相比,Pb/PAn膜电极的析氧电位负移0.13~0.36V,交换电流密度提高2~4个数量级,显示出良好的析氧电催化特性。作为析氧阳极,Pb/PAn膜电极在有色金属电解提取等方面具有潜在应用价值。     

Multiphasic Acetalization and Alkylation on Organically Modified MSU-X Silica

Mesoporous silicas were functionalized with phenyl groups and were used as solid acid catalysts in acetalization of aldehydes and ketones with ethylene glycol or methanol. It was shown that cyclohexanone as well as aromatic and linear aldehydes could be converted to the corresponding dimethylacetals in high conversion and selectivity over the catalyst. They also performed well in the isopropylation reactions of naphthalene with isopropanol.     

环糊精及其衍生物功能性能研究进展

综述了环糊精及其衍生物功能性能研究方面的进展。主要包括增溶性能、稳定效应、选择识别性能、生物酶性能、光化学性能以及电化学性能等。     

环糊精衍生物稳定性的量子化学研究

采用PM3半经验方法对11种单取代环糊精苯甲酸酯衍生物的结构进行优化,得到了它们的最稳定构型;并采用从头计算HF/6.31G方法计算各种化合物最稳定结构的能量及偶极矩等理化性质.计算结果表明,环糊精衍生物中取代基团的种类及其位置能够显著影响母体环糊精的理化性质.