Poly(aryl ether ketone) composite membrane as a high‐performance lithium‐ion batteries separator

We described the design and synthesis of a modified poly(aryl ether ketone) bearing phenolphthalein and allyl groups (P‐PAEK) via nucleophilic polycondensation. A new kind of composite separator, crosslinked P‐PAEK/polyvinylidene fluoride (c‐P‐PAEK/PVDF) membrane was successfully prepared using phase separation, phase inversion method, and UV crosslinking technique. As a separator of lithium‐ion battery, c‐P‐PAEK/PVDF membrane demonstrates high porosity and uniform distribution of pores with interconnected pathways. Low thermal shrinkage, distinct shut‐down effect, high liquid electrolyte uptake capacity, and exciting liquid electrolyte wettability of the prepared c‐P‐PAEK/PVDF membrane have been revealed through comprehensive study. Moreover, the c‐P‐PAEK/PVDF membrane was applied to assemble a conventional Li/LiFePO₄ coin cell, which exhibited hopeful cell performance. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2714–2721     

Synthesis of polyphenol microsphere‐supported palladium complex and evaluation of its catalytic performance for Heck reaction

Polyphenol microspheres were prepared by template polymerization of phenol in the presence of horseradish peroxidase as bio‐enzyme catalyst and aqueous 1,4‐dioxane as solvent. The morphology of polyphenol microspheres thus obtained was observed with a scanning electron microscope. Further, polyphenol microspheres as obtained were loaded with palladium to generate polyphenol microsphere‐supported Pd complex. Resultant Pd complex catalyst supported by polyphenol microspheres was characterized by means of Fourier transformation infrared spectrometry, X‐ray diffraction, X‐ray photoelectron spectroscopy and scanning electron microscopy, and its thermal stability was examined. Moreover, the catalytic activity of polyphenol microsphere‐supported Pd catalyst as synthesized for the Heck reactions of acrylic acid with aryl iodides was evaluated. Results indicate that the polyphenol microsphere as obtained has a diameter of about 500 nm. Polyphenol microsphere‐supported Pd catalyst, as synthesized, at a dosage of 0.37 mol% Pd, possesses good catalytic activity for the Heck reactions of acrylic acid with aryl iodides in air at a low temperature of 50°C, and it also exhibits catalytic activity for bromide and activated chlorobenzene. The polyphenol microsphere‐supported Pd complex has good thermal stability, and it can be readily separated and reused; the yield of the reaction of iodobenzene with acrylic acid remains at 82% after five recycle runs, showing promising potential as a catalyst for Heck reactions. Copyright © 2012 John Wiley & Sons, Ltd.     

单体性质对樟脑醌/胡椒环光引发活性的影响

采用实时红外光谱仪(RT-FTIR)研究了单体结构、单体配比以及活性稀释剂结构对樟脑醌(CQ)/胡椒环(BDO)引发的光聚合动力学的影响,结果发现,UDMA虽然黏度较低,但是易发生链转移反应且在聚合体系中含量较高(70 wt%),可作为氢给体猝灭激发态CQ,从而影响CQ和BDO之间的相互作用.Bis-GMA虽然黏度大,但是反应活性高,当其与少量具有给氢能力的活性稀释剂TEGDMA配合使用时,不仅对聚合体系的反应活性影响较小,而且可显著降低体系的黏度,大大提高自由基的活动能力,有利于改善CQ/BDO的引发活性.     

On characteristic integrals of Toda field theories

Characteristic integrals of Toda field theories associated to general simple Lie algebras are constructed using systematic techniques, and complete mathematical proofs are provided. Plenty of examples illustrating the results are presented in explicit forms.     

Aligned polymer fibers produced via an additive electric field

Electrospinning is known to be a highly versatile method to produce nanofibers, and several techniques have been developed to align nanofibers. In this paper, poly(vinyl alcohol) (PVA), poly(vinylpyrrolidone) (PVP), poly(propylene carbonate) (PC), poly(ethylene oxide) (PEO), PVA/Chitosan and PVA/Fe₃O₄ uniaxially aligned ultrafine fibers were obtained with electrospinning method by adding another electric field in the collection area. Alignment of the nanofibers was characterized by the use of digital cameras and field emission scanning electron microscopy, polarized Fourier transform infrared spectroscopy (FTIR), and wideangle X-ray diffraction (XRD). The mechanism of fiber alignment was investigated as well.     

Electrospun composite nanofibrous membrane as wound dressing with good adhesion

A photopolymerizationable mimic mussel protein structure monomer, dopamine methacrylamide (DMA), was synthesized. The photopolymerization of DMA was analysed by series real time near infrared spectroscopy (SRTIR). Dopamine methacrylamide/poly (ethylene oxide) (DMA/PEO) nanofibers were successfully prepared by electrospinning of aqueous DMA/PEO solution. Biocompatible nanofibrous membrane with good adhesion was produced by photocuring from the DMA/PEO nanofibers. The surface characterization and structure of the composite nanofibrous membrane were characterized by a scanning electron microscopy (SEM) and contact angle measurements. For identifying the potential crystalline of curing, a XRD method was used through comparing diffraction data. In the cell adhesion test we utilized the mouse fibroblast (L929) to exam the various use of the nanofibrous membrane as scaffolding materials for skin regeneration.     

[Re(CO)3Cl]‐Chelation‐Mediated Electronic Coupling between Two Amine Redox Sites through the 5,5′‐Positions of 2,2′‐Bipyridine

The electronic coupling between two amine redox sites bridged through the 5,5′‐positions of the [Re(CO)₃Cl]‐chelated 2,2′‐bipyridine was studied by the electrochemical, spectroscopic, and EPR analysis. Interestingly, multiple near‐infrared bands were observed in this new organic mixed‐valent system. The results are interpreted with the aid of DFT and TDDFT calculations.