Solvent-induced novel morphologies in diblock copolymer blend thin films

We report the morphology and phase behaviors of blend thin films containing two poly styrene-b-poly (methyl methacrylate) (PS-b-PMMA) diblock copolymers with different blending compositions induced by a selective solvent for the PMMA block, which were studied by transmission electron microscopy (TEM). The neat asymmetric PS-b-PMMA diblock copolymers employed in this study, respectively coded as a(1) and a(2), have similar molecular weights but different volume fractions of PS block (f(PS) = 0.273 and 0.722). Another symmetric PS-b-PMMA diblock copolymer, coded as s, which has a PS block length similar to that of a(1), was also used. For the asymmetric a(1)/a(2) blend thin films, circular multilayered structures were formed. For the asymmetric a(1)/symmetric s blend thin films, inverted phases with PMMA as the dispersed domains were observed, when the weight fraction of s was less than 50%. The origins of the morphology formation in the blend thin films via solvent treatment are discussed. Combined with the theoretical prediction by Birshtein et al. (Polymer 1992, 33, 2750), we interpret the formation of these special microstructures as due to the packing frustration induced by the difference in block lengths and the preferential interactions between the solvent and PMMA block.

Different colloids self-assembly in micromolding

Micromolding in capillaries (MIMIC) and non-conformal contact micromolding (NCCM) were employed to pattern the silica microspheres by the use of capillary forces. Three types of silica microspheres aggregations, small dot, ring and grid patterns, from the same prepatterned poly(dimethylsiloxane) (PDMS) stamps, were created by tuning the contact mode between the PDMS mold and the substrate and the concentration of silica microspheres suspension during the micromolding. The formation mechanisms of different patterns were discussed.

~(13)C-NMR方法研究酚酞聚芳醚酮砜共聚物的序列结构

通过亲核共缩聚合成了一系列酚酞聚芳醚酮砜共聚物和嵌段共聚物 ,并利用1 3C NMR方法研究了共聚物的链结构 ,通过观察酚酞单元中三个位置的季碳原子的化学位移及其相应强度的变化 ,计算共聚物中不同链段的共聚物的组成、平均序列长度和无规度 .结果表明 ,除嵌段共聚物外 ,其它共聚物的无规度均接近 1 ,表明共聚物为无规共聚物 ,而且对三个位置的季碳原子分析均得出了相同的结果.

Study on the structure change and oxygen vacation shift for Ce1-xSmxO2-y solid solution

A series of solid electrolytes Ce1-xSmxO2-y (x=0similar to0.6) were prepared by sol-gel method. XRD measurement showed that single-phase solid solution was formed in all investigated ranges at 160 degreesC, which is a significantly lower synthesis temperature compared to traditional solid state reaction. High temperature X-ray, ESR, and Raman scattering were used to characterize the samples. ESR measurement showed that ESR with sample irradiated by high-energy particle is an effective way to study the defect structure. These changes in the Raman spectrum are attributed to O vacancies, which are introduced into the lattice when tetravalent Ce4+ is substituted by trivalent Sm3+.

采用新萃取方法的PP-b-PE的研究

采用独特的二次溶解和沉淀的萃取方法,将PP b PE中的不可溶物与可溶物分离,并通过1 3C NMR,DSC,FT IR进行结构与性能的研究

Direct electron transfer between hemoglobin and a glassy carbon electrode facilitated by lipid-protected gold nanoparticles

We synthesized a kind of gold nanoparticle protected by a synthetic lipid (didodecyidimethylammonium bromide, DDAB). With the help of these gold nanoparticles, hemoglobin can exhibit a direct electron transfer (DET) reaction. The formal potential locates at -169 mV vs. Ag/AgCl. Spectral data indicated the hemoglobin on the electrode was not denatured. The lipid-protected gold nanoparticles were very stable (for at least 8 months). Their average diameter is 6.42 nm. It is the first time to use monolayer-protected nanoparticles to realize the direct electrochemistry of protein.

Green electroluminescent device with a terbium beta-diketonate complex as emissive center

In this study, a terbium complex, Tb(acac)(3)bath (acac: acetylacetone, bath: 4,7-diphenyl-1,10-phenanthroline), was synthesized and its luminescent properties were investigated compared with the reported terbium complex, Tb(acac)(3)phen (phen: phenanthroline). When it was used as an emitting material in organic electroluminescent (EL) device, the triple-layer-type device with a structure of glass substrate/ITO (indium-tin oxide)/TPD (N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine)/Tb(acac)(3)bath/Alq(3) (tris (8-hydroxyquinolinato) aluminum)/Al (aluminum) exhibited bright characteristic emission of terbium ion upon applying DC voltage. An apparent difference was observed between the photoluminescence spectrum and the EL spectrum. The EL device exhibited some characteristics of diode and the maximum luminance of 77 cd/m(2) was obtained at 17 V.

聚β-羟基丁酸酯和聚ε-己内酯的酯交换反应

以辛酸亚锡为催化剂 ,研究了聚 β 羟基丁酸酯 (PHB)与聚ε 己内酯 (PCL)在液相条件下的酯交换反应 .讨论了反应时间 ,反应温度和催化剂浓度对酯交换反应的影响 .采用1 3C NMR ,FTIR ,DSC ,WAXD和TGA等方法对PHB和PCL共聚酯 (PHB co PCL)的结构进行了表征 ,并对其结晶行为、晶体结构和热稳定性进行了研究 .结果表明 ,通过酯交换反应 ,所得到的共聚酯为嵌段共聚物 .提高反应温度和延长反应时间有利于酯交换反应的发生 .随着酯交换量的增加 ,PHB co PCL的结晶行为发生很大的变化 .但是 ,PHB co PCL晶体结构并没有因为PCL链段的引入而发生变化 ,而且它的热稳定性在空气气氛中略有提高

Species of lanthanum in Wistar rat liver

The metabolic accumulation and species of lanthanum in Wistar rat liver were investigated by ICP-MS, gel exclusion chromatography and ultrafiltration after the rats were fed by low dose of lanthanum for a long time. It was found that the content of La in the liver increased regularly with arise of dose and time of drug delivery. After the administration was stopped for a certain time a part of lanthanum in the liver Tvas metabolized, but;the metabolic rate was very slow, The lanthanum in rat liver was distributed in the soluble protein with molecular weight: of more than 60000 mostly. Rare Earth existed in the six elution peaks separated by Sephacryl S-200. The amount of lanthanum in the first elution fraction is the largest, which was 88 percent in the whole content of lanthanum in proteins with molecular weight more than 60000.

醛酮类化合物的~(13)C核磁共振波谱模拟

为饱和醛酮类化合物的1 3C核磁共振波谱模拟 .根据该类化合物的特点 ,提取了分子的拓扑特征 ,几何特征及电子特征 .应用变量最优子集回归法进行了变量的选择 ,并用这些变量构造了回归模型 .交叉验证的结果表明 ,所得数学模型比较稳定 ,并得到了较好的预测结果

镧在Wistar大鼠肝脏中的物种分布

采用ICP MS、凝胶过滤层析及超滤技术 ,通过动物实验研究了长时间、低剂量镧作用后 ,镧在Wistar大鼠肝脏中的代谢累积及其物种分布。结果表明 ,随着给药剂量的增加及作用时间的增长 ,镧在肝脏中的累积量有规律地增大 ;停止给药一段时间后 ,积累在肝脏中的镧有不同程度的代谢 ,其代谢速度很慢 ;累积在肝脏中的镧主要分布于分子量大于 6 0 0 0 0的水溶性蛋白中 ;经SephacrylS 2 0 0层析分离得到的六个蛋白洗脱峰中均含有稀土 ,在第一个洗脱峰中含量最大 ,约占肝脏含镧大分子蛋白 (分子量大于 6 0 0 0 0 )总量的 88%

Half-sandwich metal diselenolate complexes Cp#M(NO)(SePh)(2) (M = Mo or W; Cp# = Cp or MeCp) as ligands. Synthesis of selenolate-bridged heterobimetallic compounds

The reactions of half-sandwich diselenolate Mo and W complexes (CpM)-M-#(NO)(SePh)(2) (M = Mo; Cp-# = Cp' (1a), MeCp (1b); M = W; Cp-# = Cp' (1c)) with (Norb)Mo(CO)(4), Ni(COD)(2) and Fe(CO)(5) have been investigated. Treatment of (1a), (1b) and (1c) with (Norb)Mo(CO)(4) in PhMe gave the bimetallic complexes: Cp'Mo(NO)(mu -SePh)(2)Mo(CO)(4) (2a), MeCpMo(NO)(mu -SePh)(2)Mo(CO)(4) (2b) and Cp'W(NO)(mu -SePh)(2)Mo(CO)(4) (2c) in moderate yields. Irradiation of (1a) and (1c) in the presence of Fe(CO)(5) gave heterobimetallic complexes Cp'Mo(CO)(mu -SePh)(2)Fe(CO)(3) (3a) and Cp'W(NO)(mu -SePh)(2)Fe(CO)(3) (3c). Ni(COD)(2) reacts with two equivalents of (1a), (1b) and (1c) to give [Cp'Mo(NO)(mu -SePh)(2)](2)Ni (4a), [MeCpMo(NO)(mu -SePh)(2)](2)Ni (4b) and [Cp'W(NO)(mu -SePh)(2)](2)Ni (4c) in good yields. The new heterobimetallic complexes were characterized by i.r., H-1-n.m.r., C-13-n.m.r. and EI-MS spectroscopy.

脂肪胺类化合物的~(13)C核磁共振波谱模拟

对脂肪胺类化合物的1 3C核磁共振波谱进行了模拟 ,所用方法为数学模型法。为此 ,提取了共振碳原子所处化学环境的拓扑特征、几何特征及电子特征。运用变量最优子集回归法对变量进行了选择 ,用多元回归法构造了数学模型 ,得到了比较满意的预测结果。

聚β-羟基丁酸酯接枝顺丁烯二酸酐的研究

采用自由基引发聚合方法研究了聚 β-羟基丁酸酯 ( PHB)与顺丁烯二酸酐 ( MA)的接枝反应 .讨论了各种因素 ,如溶剂种类、单体浓度、引发剂浓度、反应时间和温度等对接枝反应的影响 ,确定了合成 PHB接枝 MA的最佳反应条件 .采用对酸酐基团进行化学滴定和 1 3C NMR检测等方法对产物的接枝率和结构进行了表征 .结果表明 ,MA成功的接枝到 PHB大分子链上 ,接枝率可以控制在 0 .3%～ 0 .85%范围内.

Binary alloys of nylon 1010 and ethylene-propylene copolymer: Chemical, morphological, and mechanical analysis

The modification of ethylene-propylene copolymer (EPM) has been accomplished by melt grafting of maleic anhydride (MAH) molecules promoted by radical initiators. The resulting EPM-g-MAH and EPM have been used to obtain binary nylon 1010/EPM or nylon 1010/EPM-g-MAH blends by melt mixing. It was found that the EPM-g-MAH copolymer used as the second component has a profound effect upon the properties of the resulting blends. This behavior has been attributed to a series of chemical and physicochemical interactions taking place between the two components. The interactions are due to the presence of the anhydride functionality on the copolymer and do not occur when this functionality is absent. The interaction has been confirmed by Fourier-transform infrared spectroscopy, differential scanning calorimetry, dynamic mechanical analysis, and scanning electron microscopic.