Electrochemical Sensor Based on Thioether Oligomer Poly(N‐vinylpyrrolidone)‐modified Gold Electrode for Bisphenol A Detection

Presently, bisphenol A (BPA) has been added to the list of substances of very high concern as endocrine disruptors. According to the literature, exposure to bisphenol A even at low doses may result in adverse health effects. In this study, electrochemical sensor of Bisphenol A based on thioether DDT‐Poly(N‐vinylpyrrolidone) oligomer has been developed. The thioether oligomer, which is capable of recognizing BPA, was prepared and used for gold electrode modification. The characterization of the modified gold electrode and the synthesized thioether oligomer were carried out by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), atomic force microscopy (AFM), Fourier‐transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance spectroscopy (¹H NMR) and Size exclusion chromatography (SEC). Obtained results indicate that the modified electrode shows good electrochemical activity, good sensitivity and reproducibility for BPA detection. It exhibited a good linear relationship ranging from 1 to 20 pg/mL, and the detection limit was found to be 1.9 pg/mL at S/N=3. Several interfering species such as hydroquinone, phenol and resorcinol were used and their behaviors on the modified gold electrode were investigated.     

超临界二氧化碳光聚合制备可交联含氟聚合物颗粒及应用

通过自由基无规共聚和酰化反应两步法制备了两类侧链含丙烯酸酯双键的含氟低聚物,并通过调节反应物种类、配比和链转移剂用量,制备出一系列不同双键含量、氟含量的多官能度低聚物。以制备的含氟低聚物为原料,进行超临界二氧化碳光聚合制粒。聚合得到的含氟颗粒作为增强相,加入TPGDA光固化配方中,可实现颗粒与树脂的化学交联,显著提高基材的交联密度,改善疏水性,降低吸水率,并增强热稳定性。     

Properties and applications of precision oligomer materials; where organic and polymer chemistry join forces

Precise oligomeric materials constitute a growing area of research with implications for various applications as well as fundamental studies. Notably, this field of science which can be termed macro-organic chemistry, draws inspiration from both traditional polymer chemistry and organic synthesis, combining the molecular precision of organic chemistry with the materials properties of macromolecules. Discrete oligomers enable access to unprecedented materials properties, for example, in self-assembled structures, crystallization, or optical properties. The degree of control over oligomer structures resembles many biological systems and enables the design of materials with tailored properties and the development of fundamental structure–property relationships. This Review highlights recent developments in macro-organic chemistry from synthetic concepts to materials properties, with a focus on self-assembly and molecular recognition. Finally, an outlook for future research directions is provided.     

Electrical and photoelectrical behaviour of heterojunctions based on novel oligomeric metal complexes

Naringenin‐based Schiff base ligands with 4‐aminobenzoic hydrazide were obtained as a unilateral form ( L¹ ). The ligand was oligomerized by oxidative polycondensation reaction with NaOCl as an oxidant in an aqueous alkaline medium at 90 °C to form a functional oligomer ( L² ), and its transition metal complexes such as those with Cu(II), Ni(II) and Zn(II) were prepared. The monomer and the oligomeric compounds were characterized using various techniques. Optical and electrical properties of the complexes were also investigated. All compounds showed indirect band gaps and they can be accepted as being in the semiconductor class. Organic–inorganic hybrid devices were obtained using n‐Si inorganic semiconductor and the complexes. The characteristic parameters of the devices were determined using current–voltage (I–V) and capacitance–voltage measurements in the dark. Photoelectrical properties of the devices were investigated using I–V measurements under a solar simulator with an AM1.5 global filter. Copyright © 2015 John Wiley & Sons, Ltd.     

氨基树脂交联型聚合物的合成及其取向松弛

用双羟基偶氮(或氧化偶氮)苯化合物与对苯二甲酰氯缩聚反应合成了端羟基偶氮(或氧化偶氮)苯低聚物。将其与丁醇醚化氨基树脂进行电场极化交联反应合成交联型非线性光学聚合物。利用红外光谱和紫外可见吸收光谱分别对交联反应、电场极化取向稳定性进行了研究。     

MEASUREMENT OF NUMBER AVERAGE MOLECULAR WEIGHT OF STYRENE OLIGOMER BY 13C-NMR METHOD

~(13)C-NMR ~1H-decoupled spectra of styrene polymers were assigned by comparison with modelcompounds, then used in measurements of number average molecular weights. The higher limit of an exactdetermination of the end group signal is less than a molecular weight of 10~4. For polymer samples withM_n<10~3, the results obtained from ~(13)C-NMR spectra of saturated carbon region are in excellent agreementwith the values determined by ~1H-NMR, SEC, and VPO methods, while the results from ~(13)C-NMR spectra ofphenyl C-1 carbon region are somewhat higher than the values determined by other methods.     

聚芳醚酮环状低聚物的基质辅助激光解吸电离质谱表征

采用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF-MS)技术分别对2种合成的聚芳醚酮环状低聚物进行了分析研究 ,并讨论了低聚物中不同聚合度离子组分的分布规律。实验结果表明MALDI-TOF-MS是分析环状低聚物直观、准确、快速的分析工具。     

Characterization of a series of phenyl‐capped vinyl‐terminated oligomers of styrene

Low molecular weight (MW) polystyrenes were synthesized by radical polymerization in the presence of catalytic chain‐transfer agents. Synthetic conditions are controlled to produce molecules containing one methyl group at one end as well as a double bond at the other end, capped with a phenyl group. Individual oligomers were separated by liquid chromatography, and the properties were analyzed using NMR, ultraviolet–visible (UV–vis) spectroscopy, and size exclusion chromatography with light scattering. The UV–vis spectra, proton NMR spectra, and differential refractive‐index increments exhibit an MW dependence of up to six–eight monomer units. The obtained dependencies can be used for precise characterization of the molecular weight distribution of polystyrene obtained by catalytic chain transfer. The double‐bonded end groups were found to be exclusively in the transconfiguration for all oligomers. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1099–1105, 2001     

Solid‐phase thermal polymerization of macrocyclic ethylene terephthalate dimer using various transesterification catalysts

Thermal ring‐opening polymerization of a uniform macrocyclic ethylene terephthalate dimer with and without catalyst was investigated for the first time. Although polymerization progressed without a catalyst, the reaction was extremely slow and all the products were colored. Various transesterification catalysts were tested for their activity toward this ring‐opening polymerization. Among the various catalysts, 1,3‐dichloro‐1,1,3,3‐tetrabutyldistannoxane exhibited the highest catalytic activity, and a colorless polymer with a weight‐average molecular weight of 36,100 was obtained in 100% yield by heating for 3 min at 200 °C. It is noteworthy that our method does not need a vacuum because no side products are formed during the process. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3360–3368, 2000     

Cationic polymerization of vinyl ether with a benzoate pendant: The formation of long‐lived polymers and the identification of side reactions

The cationic polymerization of 2‐[4‐(methoxycarbonyl)phenoxy] ethyl vinyl ether, a vinyl ether with a benzoate pendant, was carried out with an HCl/ZnCl₂ initiating system in methylene chloride at −15 °C. The polymerization proceeded with living/long‐lived propagating species to produce polymers with controlled molecular weights and relatively narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight ≤ ∼1.4), despite the formation of a small amount of oligomeric products during the polymerization. The structural analysis showed that the lowest molecular weight oligomer had the structure CH₃CH(OCH₂CH₂OC₆H₄COOCH₃)OCH₂CH₂OC₆H₄COOCH₃. The oligomer was formed by the reaction of the monomeric propagating species with the alcohol produced by the side reaction of the active species with water as an impurity during the early stage of polymerization. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4362–4372, 2000