Synthesis and degradation of intelligent hydrogels containing polyacetal segments

Intelligent hydrogels were first obtained by copolymerization of telechelic poly(1,3-dioxolane) (pDXL) with acrylic acid, acrylamide, N-isopropylacrylamide respectively. The synthesis and characterization of the networks were discussed. The swelling behavior of the hydrogel was dependent on the solubility parameter of the solvents and hydrogels. The networks containing polyacetal segments (pDXL) can degrade by acid in different solvents. DXL and few other cycle molecules measured by GC-MS analysis were formed after degradation. According to the degradation products, the polymerization mechanism can be testified.     

1,2-丁二醇共聚对聚对苯二甲酸乙二醇酯结晶行为及力学性能的影响

为了探索生物基乙二醇中的1,2-丁二醇(1,2-BDO)作为共聚单体对生物基聚对苯二甲酸乙二醇酯(PET)的结晶行为和力学性能的影响。 本文合成了生物基PET均聚物和不同1,2-BDO共聚单元摩尔分数的系列生物基PET共聚物(共聚单体摩尔分数分别为2.0%、2.7%和5.6%),并采用傅里叶变换红外光谱仪(FTIR)、差示扫描量热仪(DSC)和力学测试等技术手段研究了其结晶行为和力学性能。 结果表明,随着1,2-BDO共聚单元摩尔分数的增加,PET共聚物的熔融温度、结晶速率及结晶度均明显降低,表明1,2-BDO共聚单体的引入破坏了PET分子链的规整性,阻碍了PET链段的结晶。 PET材料的拉伸强度随着1,2-BDO共聚单元摩尔分数的增加而降低,而弯曲强度和弯曲模量略有升高。     

Excess molar enthalpies of the ternary mixtures: (diisopropyl ether or 2-methyltetrahydrofuran) + cyclohexane + n-heptane at 298.15 K

Microcalorimetric measurements of excess molar enthalpies, at 298.15 K, are reported for the two ternary systems formed by mixing either diisopropyl ether or 2-methyltetrahydrofuran with binary mixtures of cyclohexane and n-heptane. Smooth representations of the results are presented and used to construct constant excess molar enthalpy contours on Roozeboom diagrams. It is shown that useful estimates of the ternary enthalpies can be obtained from the Liebermann and Fried model, using only the physical properties of the components and their binary mixtures.     

Structural and photocatalytic properties of the new solid photocatalyst In2BiTaO7

In₂BiTaO₇ was synthesized using the solid-state reaction method and its photocatalytic properties were investigated. The results of powder X-ray diffraction (XRD) indicated that the compound crystallizes in the pyrochlore-type structure, cubic system with space group Fd-3m. The lattice parameter is 10.6972(1) ?. In addition, the compound shows strong optical absorption in the visible region (λ > 420 nm) and the band gap of In₂BiTaO₇ was estimated to be about 2.47 eV. For the photocatalytic reaction, H₂ or O₂ evolution was observed from CH₃OH/H₂O or AgNO₃ solution respectively with In₂BiTaO₇ as the photocatalyst under visible light irradiation, indicating that In₂BiTaO₇ is responsive to visible light for splitting water. Furthermore, the catalyst remained photoactive in the wavelength range up to 510 nm. Photocatalytic degradation of methylene blue (MB) dye over the compound was further investigated under visible light irradiation. The results showed that complete removal of aqueous MB could be achieved after irradiation for 135 min over In₂BiTaO₇. Furthermore, under visible light irradiation In₂BiTaO₇ showed markedly higher catalytic activity compared to P-25 for MB photocatalytic degradation.     

含氟丙烯酸酯共聚乳液及其膜表面特性的研究

以十二烷基硫酸钠 (SDS)和OP 10混合乳化剂 ,制备了甲基丙烯酸全氟辛基乙酯 (FMA8) 甲基丙烯酸丁酯 (BMA) 甲基丙烯酸 (MAA)共聚乳液 .通过DSC、FT IR、1 H NMR对共聚物的结构、组成进行了表征研究 .采用JZHY 180界面张力仪研究了共聚乳液膜表面的性质 ,结果表明 ,随着共聚物中全氟单体含量的增加 ,共聚物膜的表面能显著降低 ,当全氟单体的含量达到 2 5wt %时 ,其表面能降低到 19 74mJ m2 .X ray光电子能谱(XPS)对共聚物表面原子组成的分析结果表明 ,共聚物表面氟的含量远高于其平均含量 ,证明了含氟基团的趋表现象 .经退火处理 ,共聚物膜表面的氟含量增加 ,表面自由能降低     

Investigations into the Pd-catalysed cross-coupling of phenylacetylene with aryl chlorides: simple one-pot procedure and the effect of ZnCl2 co-catalysis

[PdCl(C6H3(OPPri2)2-2,6)] 1 catalyses the coupling of electron-rich, electron-neutral and electron-deficient aryl chlorides with phenylacetylene in the presence of ZnCl2 as cocatalyst to give the products in modest to excellent yields.     

Thermosensitive polymeric vesicles self-assembled by PNIPAAm-b-PPG-b-PNIPAAm triblock copolymers

PNIPAAm-b-PPG-b-PNIPAAm triblock copolymers were prepared by redox polymerization. The self-assembly behavior and thermosensitive property of the copolymers in water were studied using ¹H-NMR, TEM and a UV spectrophotometer. The results showed that the LCST of the copolymers was 32 °C, which was consistent with that of pure PNIPAAm. The copolymers could form a vesicular structure in an aqueous solution by self-assembly. The hollow structure of the PNIPAAm-b-PPG-b-PNIPAAm vesicles combined with the temperature-sensitive property may enable many potential applications of the vesicles.     

Self-assembly of electron donor-acceptor dyads into ordered architectures in two and three dimensions: surface patterning and columnar "double cables"

We report the synthesis and characterization of covalent dyads and multiads of electron acceptors (A) and donors (D), with the purpose of exploiting their nanophase separation behavior toward (a) two-dimensional (2D) surface patterning with well-defined integrated arrays of dissimilar molecular electronic features and (b) bulk self-assembly to noncovalent columnar versions of the so-called "double cable" systems, the likes of which could eventually provide side-by-side percolation pathways for electrons and holes in solar cells. Soluble, alkylated hexa-peri-hexabenzocoronenes (HBCs) bearing tethered anthraquinones (AQs) are shown by scanning tunneling microscopy (STM) to self-assemble at the solution-graphite interface into either defect-rich polycrystalline monolayers or extended 2D crystalline domains, depending on the number of tethered AQs. In the bulk, the thermal stability of the room-temperature HBC columnar phase is increased, which is attributed to the desired nanotriphase separation of HBC columns, insulating alkyl sheaths, and AQ units. Homeotropic alignment (columns normal to surfaces), predicted to be ideal for potential exploitation of such "double cables" in photovoltaic devices, is demonstrated.     

C反应蛋白免疫电极的研究

C反应蛋白(CRP)是临床医学中重要的检验项目之一。本文以醋酸纤维素-戊二醛-己二胺载体膜与自制的原电极研制成非标记CRP免疫电极。研究了载体膜的组成对电极灵敏度的影响,并采用均匀设计法对载体膜的活化条件、抗原抗体结合时间以及电极测试条件等进行了优化。该电极响应快、灵敏度高、重现性和稳定性良好。在最佳实验条件下,电极线性范围为1.8～60μg/ml,所得线性回归方程为E=0.2+0.091[CRP];相关系数0.9989。在用于血清样品的测定中,取得满意结果。