Efficient peroxide decoloration of azo dye catalyzed by polyethylene glycol-linked manganese chlorin derivative

We reported here that polyethylene glycol (PEG)-linked manganese pyrochlorophyllide a (PEG-MnPChlide a) possesses remarkable catalytic activity comparable to horseradish peroxidase (HRP). The PEG-MnPChlide a catalyzed the oxidation decoloration reaction of C.I. Acid Orange 7 by hydrogen peroxide under a mild aqueous condition, pH 8.0 at 25 °C. The manganese pyrochlorophyride a methylester (MnPChlide a ME) dissolved in a Triton X-100 micellar solution also exhibited the catalytic activity, indicating the micellar environment plays an important role in the catalytic reaction. The reaction rate was accelerated by addition of imidazole. The catalytic reactions were analyzed by Michaelis–Menten kinetics, revealing that the higher reactivity of catalyst–substrate complex is responsible for the present catalytic reaction system.     

A study of phase transfer processes of Ag nanoparticles

With the protection of sodium oleate, Ag nanoparticles are produced through the reduction of AgNO₃ with NaBH₄ in an aqueous solution. The possible mechanism of phase transfer of the Ag nanoparticles was discussed. At a suitable concentration of sodium oleate, after adding NaH₂PO₄, the oleic acid molecule can change its position on the surface of Ag nanoparticles under the effects of water and toluene and become amphipathic. So most of the nanoparticles form a film between water/toluene. For the case of a higher concentration of sodium oleate, excess sodium oleate will form a closed monolayer film on the surface of the Ag nanoparticles. After adding NaH₂PO₄, the oleic acid molecule cannot move on the Ag nanoparticles surface, thus the colloid particles are hydrophobic but not amphipathic. So most of the particles transfer to the organic phase. UV–Vis spectra, TEM and conventional metallographic microscopy are used to characterize the Ag nanoparticles and nanoparticles films.     

Development of a new open-tubular capillary electrochromatography method for in vitro monitoring of toxic aromatic amines distribution in rat blood

Exposure to aromatic amines from different industrial and agricultural activities entails a substantial risk of deleterious somatic effects, genetic damage and cancer development. Thus, a new and simple method for separation and analysis of aromatic amines has been developed by open-tubular capillary electrochromatography with a novel amphipathic block copolymer (poly(tert-butyl acrylate)(127)-block-poly(glycidyl methacrylate)(86)) coating based on its self-assembled property. Key factors affecting the separation efficiency of the test analytes, such as pH, buffer concentration and selective solvent, were studied in detail. Meanwhile, method validation was well evaluated by linearity (≥0.998), detection limit and recovery. Application of this developed protocol on in vitro monitoring of the target aromatic amines distribution in rat blood demonstrated its potential usage for separation and determination of aromatic amines in biological samples. Additionally, for assimilating more polymeric materials into analysis of aromatic amines, the effect of morphology changes of the amphipathic block copolymer coating on open-tubular capillary electrochromatography separation was also studied, and the result revealed that the block copolymer coating could play the same role as surfactant.     

基于Ugi多组分反应的海藻酸酰胺衍生物改性二氧化硅纳米粒子的制备

采用海藻酸酰胺衍生物通过Ugi多组分反应制备了新颖的聚合物-二氧化硅(Oct-Alg-Si O_2)纳米粒子.通过氢核磁共振波谱(~1H NMR)和X射线光电子能谱(XPS)对Oct-Alg-Si O_2的结构和表面元素组分进行了表征.采用透射电子显微镜(TEM)、Zeta电位和激光粒度分析仪对Oct-Alg-Si O_2的形貌、粒径和胶体性能进行了探索.结果表明,海藻酸酰胺衍生物共价接枝到氨基二氧化硅(Si O_2-NH_2)纳米粒子的表面,提高了其平均直径,调控了其Zeta电位,在水介质中能够表现出良好的分散稳定性.以10%的液体石蜡为油相,采用Oct-Alg-Si O_2制备了Pickering乳液.在油水界面能够形成液滴粒径为5.7μm的稳定Pickering乳液.随着水相p H值的增大,乳液体积分数增大,稳定性增强.细胞相容性实验结果表明,Oct-Alg-Si O_2纳米粒子具有极好的生物相容性.     

两亲性笼型倍半硅氧烷（POSS）杂化高分子的自组装

笼型倍半硅氧烷（POSS）是一种由si-O-si键构成的高度对称笼型结构、端基具有极高的可设计性及高反应性新型有机一无机杂化材料,空间尺寸1～3nm;选取带有特定结构的光、电、磁等特性单元,利用活性聚合的方法可制得不同形状的POSS-Polymer杂化材料,通过溶剂、热、电、纳米印刷等方法“梳理”分子链结构,使之成为长程有序的纳米序列结构材料,获取具有预期结构和功能特性的高分子实体。本文从分子自组装的角度对两亲性笼型倍半硅氧烷（POSS）杂化高分子材料进行了介绍,分析了其在生物医药用高分子、智能高分子及低介电高分子材料等多个领域内的最新研究进展,并对今后的发展做了相关的预测与展望。