Block Copolymesrs of Ethylene Oxide and Styrene Oxide. New Copolymer Surfactants(Ⅱ)

~~Block Copolymesrs of Ethylene Oxide and Styrene Oxide. New Copolymer Surfactants(Ⅱ)@David Attwood$School of Pharmacy and Pharmaceutical Science,University of Manchester!Manchester M139PL,U K @Colin Booth$Departmentof Chemistry,U niversity of Manchester!Manchester M139PL,U K.~~…     

Block Copolymers of Ethylene Oxide and Styrene Oxide.New Copolymer Surfactants（ Ⅱ ）.

3.2. Association Number Figure 5 shows the dependence of the weight-average association number (Nw,measured by static light scattering, solution temperature 30 °C) on hydrophobe block length for ES and ESEblock copolymers.     

Comments on the Paper “Heterogeneous Nucleation of Water Vapor on Monodisperse Ag and NaCl Particles with Diameters between 6 and 18 nm”

Please click here to find the Original Article to which this Letter refers:: http://dx.doi.org/10.1080/02786828508959039     

Density-Functional Theoretical Study on the Role of Lewis and Brønsted Acid Sites on CeO2(110) Surfaces for Nitrile Hydration

Hydration of cyanopyridine on CeO₂(110) surfaces was studied using periodic DFT+U calculations. One of two adsorption modes of 2-cyanopyridine occurs with two-point interaction which causes substrate specificity. A catalytic cycle for the hydration of 2-cyanopyridine was proposed. Cooperativity of Lewis and Brønsted acid sites was found to stabilize the intermediates for the hydration.     

Fabrication and Properties of Superhydrophobic Surfaces Based on Low-Density Polyethylene/Ethylene–Propylene–Diene Terpolymer Thermoplastic Vulcanizate

A simple, effective, and inexpensive method has been developed to fabricate superhydrophobic surfaces based on low-density-polyethylene/ethylene–propylene–diene terpolymer thermoplastic vulcanizate. Field emission scanning electron microscope research showed that the rough microstructure could be fabricated successfully in the thermoplastic vulcanizate surface where metallographic sandpaper was used as molding template; moreover, the micrometer scale plastic deformation of thermoplastic vulcanizate matrix could be observed obviously, leading to the increasing surface roughness. Wettability test showed that the series rough thermoplastic vulcanizate surfaces that were molded with sandpapers had strong hydrophobic property; furthermore, the sliding angle value was less than 10°. Metallographic sandpaper template exhibited well re-used property.     

Dissociation of molecular oxygen on unpromoted and cesium‐promoted Ag(111) surfaces

Density functional calculations for the dissociation of molecular oxygen on a Ag₁₀ cluster model (seven surface and three subsurface atoms) of the [111] surface of silver are presented. The calculations show that the reaction pathway for the dissociation of molecular oxygen depends on the amount of cesium present on the surface. For the unpromoted surface, dissociation should have a low rate as the process is activated. As a single Cs atom is added to the cluster, O₂ should readily dissociate since the process is kinetically and thermochemically favored. However, as a second Cs atom is added, the dissociation of O₂ is quenched as the process is highly activated. This revised version was published online in July 2006 with corrections to the Cover Date.     

Investigation of F?rster Resonance Energy Transfer (FRET) and Competition of Fluorescent Dyes on DNA Microparticles

Fluorescent labeling is widely used to investigate the structural stability and changes to DNA nano- and microstructures. Despite this, the conventional method for observing DNA structures has several limitations in terms of cost-efficiency. This paper introduces a DNA spherical particle stained with DNA intercalating dyes (SYBR Green and SYTOX Orange) as tracers and reports the interaction between multiple dyes. The interference between the dyes was analyzed in terms of Förster resonance energy transfer (FRET) and competition. The changes in the fluorescence intensity by FRET were uniform, regardless of the sequence. The competition effect could occur when several dyes were added simultaneously. These properties are expected to help in the design of multicolor tracers in bioimaging and environmental applications.     

Attenuation of Combined Nickel(II) Oxide and Manganese(II,III) Oxide Nanoparticles’ Adverse Effects with a Complex of Bioprotectors

Stable suspensions of NiO and Mn₃O₄ nanoparticles (NPs) with a mean (±s.d.) diameter of 16.7 ± 8.2 and 18.4 ± 5.4 nm, respectively, purposefully prepared by laser ablation of 99.99% pure nickel or manganese in de-ionized water, were repeatedly injected intraperitoneally (IP) to rats at a dose of 2.5 mg/kg 3 times a week up to 18 injections, either alone or in combination. A group of rats was injected with this combination with the background oral administration of a “bio-protective complex” (BPC) comprising pectin, vitamins A, C, E, glutamate, glycine, N-acetylcysteine, selenium, iodide and omega-3 PUFA, this composition having been chosen based on mechanistic considerations and previous experience. After the termination of injections, many functional and biochemical indices and histopathological features (with morphometric assessment) of the liver, spleen, kidneys and brain were evaluated for signs of toxicity. The Ni and Mn content of these organs was measured with the help of the atomic emission and electron paramagnetic resonance spectroscopies. We obtained blood leukocytes for performing the RAPD (Random Amplified Polymorphic DNA) test. Although both metallic NPs proved adversely bio-active in many respects considered in this study, Mn₃O₄-NPs were somewhat more noxious than NiO-NPs as concerns most of the non-specific toxicity manifestations and they induced more marked damage to neurons in the striatum and the hippocampus, which may be considered an experimental correlate of the manganese-induced Parkinsonism. The comparative solubility of the Mn₃O₄-NPs and NiO-NPs in a biological medium is discussed as one of the factors underlying the difference in their toxicokinetics and toxicities. The BPC has attenuated both the organ-systemic toxicity and the genotoxicity of Mn₃O₄-NPs in combination with NiO-NPs.     

A vibrational study of the activation sequence of C–H and C–C bonds of isobutene and 1-butene on Mo(110) and (4 × 4)-C/Mo(110) surfaces

The thermal decomposition pathways of isobutene and 1-butene on both Mo(110) and 4 × 4-C/Mo(110) surfaces have been studied using high-resolution electron energy loss spectroscopy (HREELS) in order to highlight the substantially different activities of these two surfaces towards the cleavage of C–H and C–C bonds. On clean Mo(110), the CH₂ group of isobutene decomposes upon heating to 150 K, producing either a /-bonded isobutenylidene [(CH₃)₂CCH] species or a 1,1-di-/-bonded isobutenyl [(CH₃)₂CC] species. Upon further heating, extensive C–H bond scission occurs to form hydrocarbon fragments which do not contain CH₃ or CH₂ groups, but appear to have largely intact carbon skeletons. By contrast, isobutene is molecularly adsorbed on the carbide-modified surface at 150 K. Further heating produces isobutylidyne [(CH₃)₂HCC] by 300 K, which subsequently decomposes via C–C bond scission to generate surface methyl groups. The different activation sequence of the C–H and C–C bonds of isobutene on clean and carbide-modified Mo(110) surfaces is also qualitatively confirmed by comparative studies of 1-butene on the two surfaces.     

Investigation on Production and Markets of Silica Bricks in China

The annual output of China‘s silica brick amounts up to over 300 thousand tons, which accounts for more than 70% of the total oupout of silica bricks in the world. Besides satisfying domestic markets, China‘s silica bricks have been exported to many countries and retions such as Japan, USA etc. In this paper, the situation of silica bricks production, technology, sales and exporting have been described. Also suggestions on improvement of silica bricks quality and exporting, corporation with foreign partners have been put forward in order to win larger market share both aat home and abroad.     

Letter to the Editor: Reply to Comments on the Paper “Heterogeneous Nucleation of Water Vapor on Monodispersed Ag and NaCl Particles with Diameters between 6 and 18 nm”

Please click here to find the Letter to the Editor to which this Response refers: http://dx.doi.org/10.1080/02786828608959113     

海水中~(110m)Ag分析方法研究进展

~(110m )Ag是核反应堆的活化产物,是我国目前核电主要堆型(华龙一号、ACRP1000)的关键核素之一。目前,针对海洋生物对~(110m )Ag的富集能力、~(110m )Ag在生物体中的分布等方面已开展了较多的研究工作。但是,对海水中~(110m )Ag分析方法方面研究报道较少。本文从海洋环境中放射性核素~(110m )Ag的来源、分析方法等方面进行了总结和讨论,在此基础上提出了加强海洋环境中~(110m )Ag分析方法的优化,对评价海洋环境中~(110m )Ag对海洋的影响和核事故后果评价等具有重要意义。     

Characterization of Pt?CAu and Ni?CAu Clusters on TiO2(110)

The surface composition and properties of Pt?CAu and Ni?CAu clusters on TiO₂(110) have been studied by scanning tunneling microscopy (STM), low energy ion scattering (LEIS) and soft X-ray photoelectron spectroscopy (sXPS). STM studies show that bimetallic clusters are formed during sequential deposition of the two metals, regardless of the order of deposition. At the 2?ML of Au/2?ML of Pt or Ni coverages studied here, the second metal contributes to the growth of existing clusters rather than forming new pure metal clusters. LEIS experiments demonstrate that the surfaces of the bimetallic clusters are almost 100% Au when 2?ML of Au is deposited on top of 2?ML of Pt or Ni. However, a much larger fraction of Pt or Ni (50 and 20%, respectively) remains at the surface when 2?ML of Pt or Ni is deposited on 2?ML of Au, most likely due to limited diffusion of atoms within the clusters at room temperature. According to sXPS investigations, the binding energies of the metals in the bimetallic clusters are shifted from those observed for pure metal clusters; the Pt(4f_7/2) and Ni(3p_3/2) peaks are shifted to lower binding energies while the position of the Au(4f_7/2) peak is dominated by surface core level shifts. Pure Pt clusters as well as 0.4?ML of Au on 2 ML of Pt clusters reduce the titania support upon encapsulation after annealing to 800?K, whereas 2?ML of Au on 2?ML of Pt clusters do not reduce titania, presumably because there is no Pt at the surface of the clusters. Pure Ni clusters are also known to become encapsulated upon heating, but the reduction of titania is much less extensive compared to that of pure Pt clusters.     

Effect of Calcination Temperature on Structure and Properties of Sn–Nb2O5/α-Al2O3 Catalyst for Ethylene Oxide Hydration

Sn–Nb₂O₅/α-Al₂O₃ catalysts were prepared by impregnation and tested for ethylene oxide (EO) hydration to form ethylene glycol. The effect of the calcination temperature on the structure, acidity, H₂O and EO adsorption properties and catalytic performance of the catalyst were investigated by using XRD, TG-DTA, IR, NH₃-TPD and EO-TPD. It was found that the phase compositions, acidity, the EO adsorption strength and water adsorption capacity of the Sn–Nb₂O₅/α-Al₂O₃ catalyst were markedly influenced by the calcination temperature. The catalyst calcined at a temperature between 350 and 400 °C showed the best catalytic performance. A correlation between catalytic performance and characterization was proposed.