Fluorescent materials based on phosphazene derivatives and their applications: Sensors and optoelectronic devices

Phosphazenes, one of the most important classes of organophosphorus compounds containing phosphorus (V) with double bonds between P and N, can be cyclic molecules or high molecular weight polymers that play an important and dominant role in advanced inorganic materials. Phosphazenes have been the subject of many studies over the past two decades as an excellent synthetic platform for the development of fluorescent materials. This study is conducted to evaluate the contribution of phosphazene chemistry to the preparation of fluorescent materials and to emphasize its importance in development of sophisticated materials. This review provides detailed information about the latest developments in the field of cyclic-, dendrimeric- and polymeric phosphazenes based fluorescent materials and their application examples of sensors (fluorescent and electrochemical) and optoelectronic devices (OLED, OFET and electrochromic devices). The future perspective of fluorescence materials based on phosphazenes is also discussed.     

高倍率铌基氧化物负极材料的研究进展

锂离子储能器件具有高能量密度与绿色环保等优点, 在未来新能源汽车和大规模储能领域中将显示出巨大的潜力. 然而, 由于传统锂离子负极材料如石墨、 硅存在电化学动力学缓慢与高倍率下的安全性等问题, 无法满足目前能源消费终端日益增长的快速充放电性能要求. 因此, 开发有利于锂离子快速嵌入/脱出、 安全性与稳定性优异的负极材料至关重要. 相比于传统的负极材料, 铌基氧化物具有合适的理论容量、 更安全的工作电位、 稳定且快速的离子传输通道等优点. 本文综述了高倍率铌基氧化物负极材料在锂离子储能器件领域的最新研究进展, 重点介绍了典型铌基氧化物的储锂机理与改性手段, 并对铌基氧化物负极材料未来的发展与挑战进行了展望.     

Radical reduction of Passerini 3CR adducts by SmI2/HMPA

The Passerini 3-CR adducts of substituted cinnamaldehydes,isocyanides and acetic acid were treated with SmI₂/HMPA in dry tetrahydrofuran（THF） at room temperature,andβ,γ-unsaturated amides were obtained in moderate yields.The reaction was supposed involving a radical reduction procedure.     

SBA/PVC复合树脂的制备与表征

采用聚丙烯酸正丁酯(PBA)改性的丁苯(SBR)胶乳为种子乳液(SBA),通过乳液接枝共聚氯乙烯制备了SBA/PVC复合树脂.通过粒径分析仪、动态力学分析仪(DMA)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)等测试手段,表征了复合胶乳粒的粒径与形态,以及材料的形态结构.粒径分析表明PVC确实包覆在SBA上;TEM研究结果显示SBA/PVC胶乳粒子呈现明显的核壳结构,PBA加入可提高SBR在复合材料中的分散性;DMA分析表明SBA/PVC复合树脂在低温区呈现了一个宽而弱的转变峰,揭示了接枝过渡层的微观结构特征;研究了交联剂和PBA用量对材料性能的影响,结果表明在PBA含量较低时,SBA/PVC复合树脂就显示了优良的冲击性能,且SEM照片显示材料断面形貌为特征性韧性断裂.     

聚苯基硅氧烷与聚甲基苯基硅氧烷改性环氧树脂的合成与性能比较

热熔法制备了一系列聚苯基甲氧基硅氧烷(PPMS)、聚甲基苯基甲氧基硅氧烷(PMPS)改性环氧树脂,通过环氧值、红外光谱(IR)分析表明聚硅氧烷接枝了E-20环氧树脂且环氧基保持不变.探讨了有机硅含量对改性树脂固化体系耐热性能及韧性的影响.实验表明,当E-20环氧树脂与PPMS、PMPS的质量比为7∶3时,改性树脂固化体系的耐热性能明显提高,玻璃化转变温度(Tg)为95.8、88.3℃,分别比改性前提高了9.0℃和1.5℃;质量损失50%时的热分解温度(Td)为476.5、487.8℃,分别比改性前提高了58.3℃和69.5℃.与ED-30固化体系相比,EPMS-30固化物的耐热性能,韧性等力学性能提高的更加明显,并且还具有优良的涂膜性能.     

Adsorption of lanthanides(III) from aqueous solutions by fullerene black modified with di(2-ethylhexyl)phosphoric acid

Fullerene black (FB) - a product of electric arc graphite vaporization after extraction of fullerenes - was modified with the di(2-ethylhexyl)phosphoric acid (D2EHPA). The distribution of D2EHPA between FB and aqueous HNO₃ solutions has been studied. The effect of HNO₃ concentration in the aqueous phase and that of D2EHPA concentration in the sorbent phase on the adsorption of microquantities of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y nitrates from HNO₃ solutions by D2EHPA-modified FB are considered. The stoichiometry of the sorbed complexes has been determined by the slope analysis method. The efficiency of lanthanides’ adsorption increases with an increase in the element atomic number. A considerable synergistic effect has been observed upon the addition of the neutral bidentate tetraphenylmethylenediphosphine dioxide ligand to D2EHPA in the sorbent phase.      

聚烯烃催化剂载体硅胶研发进展

以Ziegler-Natta催化剂和茂金属催化剂为例,介绍了聚烯烃均相催化剂的负载化技术以及载体选择的影响因素,明确了载体的强度、密度、总孔容、孔分布、孔径、粒度和颗粒形状等物理性质是选择载体要考虑的主要因素。综述了聚烯烃催化剂载体硅胶的结构特征和性能特征,并对聚烯烃催化剂载体硅胶的合成机理、影响因素进行了详细介绍。此类载体硅胶比表面积280~320m2/g、堆密度0.28~0.32g/cm3、孔容1.40~1.70cm3/g、平均孔径18~22nm。建议通过开展对不同性能硅胶(如更小粒径、不同元素改性等)的研究开发,以满足不同催化剂对载体硅胶的特殊要求。     

Modification of poorly bioactive sinomenine into more potent immunosuppressive agents by embedding of drug-like fragments

Embedment of drug-like heterocyclic moieties was successfully employed in the novel modification of the readily available but poorly bioactive natural alkaloid sinomenine. Application of the newly proposed approach afforded a number of more potent sinomenine-like molecules with a significantly high hit rate. Among these new analogous, up to 500-fold increase of in vitro immunosuppressive activity was achieved. Further biological experiments of representative compound 4b indicated that it might inhibit NF-κB activation induced by TNF-α in a dose dependent way and showed remarkable in vivo treatment effects against the mouse experimental autoimmune uveoretinitis (EAU) disease models.     

Type I thyroplasty: Pitfalls of modifying the Isshiki approach.How I do it

The Isshiki type I thyroplasty medializes the membranous portion of thevocal fold. Since its introduction into this country more than 10 years ago, several authors have reported modifications of the Isshiki approach primarily for the purpose of speeding the operation and “simplifying” the procedure. The major modifications have included: (a) incision, versus retraction, of the strap muscles; (b) removing the window external perichondrium; (c) varying the placement and size of the window and prosthesis; (d) removal of the window cartilage; (e) fiberoptic versus nonvisualization of the larynx intraoperatively; (f) incision of the inner perichondrium; and (d) use of silastic block substitutes. The principles of Isshiki's original technique will be reiterated in the ongoing discussion, and the reasons for not modifying certain aspects of the technique will be examined from the standpoint of complications and negative impact that manifest when modification is done.