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用稀土化合物改性的钛系载体催化剂(SN催化剂)进行苯乙烯和丙烯顺序嵌段共聚合(Sequentialblockcopolymerization)的研究.考察了苯乙烯预聚时间、单体比、外加给电子体(EB)、烷基铝浓度、催化剂浓度和聚合温度等条件对共聚合的影响.发现外加酯(EB)降低了共聚合反应催化活性,在EB/Ti摩尔比为5范围内,外酯有助于提高嵌段共聚物(iPS—b—iPP)中PS段和PP段的等规度及增加苯乙烯链节含量.SN型催化剂对苯乙烯一丙烯嵌段共聚合有较高的催化活性,催化效率在100g聚合物/g-Ti以上.共聚物通过溶剂革取分级除去均聚物后,所得嵌段共聚物中苯乙烯链节含量可在15~85mol%之间调节.其结构表征续见第II报. 相似文献
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采用微波辅助法制备了氧化铜(CuO)材料,其结晶度好,没有杂质,呈现片层堆叠而成的块状结构.以CuO材料修饰玻碳电极作为工作电极(CuO/GCE),饱和甘汞电极作为参比电极,铂丝电极作为对电极,在碱性条件下对葡萄糖溶液进行电化学性能检测.该传感器对520 nM到2.0 mM浓度范围内的葡萄糖溶液实现了优良的检测性能,灵敏度为2491.362μA·cm-2·mM-1,检测限为216 nM(S/N=3),在2 s内就可以完成反应.丙烯酸等物质对传感器的影响可以忽略,具有良好的抗干扰性. 相似文献
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Nehete UN Roesky HW Zhu H Nembenna S Schmidt HG Noltemeyer M Bogdanov D Samwer K 《Inorganic chemistry》2005,44(20):7243-7248
The cobalt(II) and iron(II) siloxane compounds were prepared by the reaction of lipophilic N-bonded silanetriol 1 with metal silylamides M[N(SiMe3)2]2 (M = Co (2), Fe (3)) in a 1:1 and 3:4 molar ratio, respectively. A plot of 1/chi versus temperature in the range of 2-300 K indicates the paramagnetic behavior of 2 and 3. The composition and molecular structures of 2 and 3 were fully determined by IR, elemental analysis, and X-ray crystal structural analyses. Compound 2 possesses a pseudo-4-fold (S4) symmetry, whereas 3 reveals an inversion center. Compound 2 represents a tetracobalt(II) drum while 3 exhibits an octairon(II) cage containing siloxane ligands. 相似文献
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Design of novel substituted phthalocyanines; synthesis and fluorescence,DFT, photovoltaic properties
Mehmet Salih AIRTA Derya GÜNG
RDÜ SOLUN Ümit YILDIKO Abdullah
ZKARTAL 《Turkish Journal of Chemistry》2020,44(6):1574
The 4-(2-[3,4-dimethoxyphenoxy] phenoxy) phthalonitrile was synthesized as the starting material of new syntheses. Zinc, copper, and cobalt phthalocyanines were achieved by reaction of starting compound with Zn(CH3COO)2, CuCl2, and CoCl2 metal salts. Basic spectroscopic methods such as nuclear magnetic resonance electronic absorption, mass and infrared spectrometry were used in the structural characterization of the compounds. Absorption, excitation, and emission measurements of the fluorescence zinc phthalocyanine compound were also investigated in THF. Then, structural, energy, and electronic properties for synthesized metallophthalocyanines were determined by quantum chemical calculations, including the DFT method. The bandgap of HOMO and LUMO was determined to be chemically active. Global reactivity (I, A, η, s, μ, χ, ω) and nonlinear properties were studied. In addition, molecular electrostatic potential (MEP) maps were drawn to identify potential reactive regions of metallophthalocyanine (M-Pc) compounds. Photovoltaic performances of phthalocyanine compounds for dye sensitive solar cells were investigated. The solar conversion efficiency of DSSC based on copper, zinc, and cobalt phthalocyanine compounds was 1.69%, 1.35%, and 1.54%, respectively. The compounds have good solubility and show nonlinear optical properties. Zinc phthalocyanine gave fluorescence emission. 相似文献
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酶促合成全氟辛酸半乳糖脂 总被引:4,自引:1,他引:4
首次报道了酶促合成含氟糖脂。在IM-60脂肪酶催化下以85%产率得到了全氟辛酸半乳糖脂。 相似文献
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Seungho Lee Hai Doo Kwen Sung Kwang Lee Sachin Vilas Nehete 《Analytical and bioanalytical chemistry》2010,396(4):1581-1588
Polyamidoamine (PAMAM) dendrimers have an amine surface and an ethylenediamine core and are of great interest in various applications
such as in drug delivery. Physiochemical properties of PAMAM dendrimers vary with pH. At neutral to basic pH, PAMAM dendrimers
are either weakly charged or uncharged and tend to adsorb on to the neutral packing material, making chromatographic separation
of the dendrimers difficult. Asymmetrical flow field-flow fractionation (AsFlFFF) was tested as an alternative to the chromatographic
techniques for separation of the PAMAM dendrimers. AsFlFFF provided generation-based separation of the dendrimers even at
neutral and basic pH. The elution time increased gradually as the generation number (and thus the size) increased. Separation
of impurities such as generational or missing-arm impurities and aggregates from the main population was also achieved. Electrostatic
and hydrophobic interactions (e.g., repulsive elecrostatic interaction among the dendrimer molecules or attractive hydrophobic
interaction between the dendrimer molecules and the membrane) may result in an inaccurate size measurement. Careful optimization
of experimental conditions such as the flow rate, pH, and the salt concentration may be required to minimize the interactions
with the membrane. AsFlFFF was also tested for a study on the interaction between the PAMAM dendrimers and proteins. AsFlFFF
was able to show the growth in the size of bovine serum albumin (BSA) when BSA is mixed with increasing amounts of PAMAM dendrimers.
Results suggest that, with proper optimization, AsFlFFF could become a useful tool for separation and characterization of
large charged molecules such as PAMAM dendrimers. 相似文献