PVC/PBD-b-PMMA共混体系相容性的研究

采用ＤＭＡ和ＴＥＭ系统研究了聚丁二烯－聚甲基丙烯酸甲酯的嵌段共聚物（ＰＢＤ－ｂ－ＰＭＭＡ）与聚氯乙烯（ＰＶＣ）共混体系的相容性问题。结果表明：ＰＶＣ／ＰＢＤ－ｂ－ＰＭＭＡ共混体系具有部分相溶性。相容的程度与共混体系的组成、组分聚合物的分子量以及共聚物中ＰＢＤ和ＰＭＭＡ嵌段的比例密切相关。     

Effects of hydrothermal post-treatment on microstructures and morphology of titanate nanoribbons

Titanate nanoribbons were prepared via a hydrothermal treatment of rutile-type TiO₂ powders in a 10 M NaOH solution at 200 °C for 48 h. The as-prepared titanate nanoribbons were then hydrothermally post-treated at 150 °C for 12-36 h. The titanate nanoribbons before and after hydrothermal post-treatment were characterized with FESEM, XRD, TEM, UV-VIS and nitrogen adsorption-desorption isotherms. The results showed that the hydrothermal post-treatment not only promoted the phase transformation from titanate to anatase TiO₂, but also was beneficial to the removal of Na⁺ ions remained in the titanate nanoribbons. After hydrothermal post-treatment, the TiO₂ samples retained the one-dimensional structure feature of the titanate nanoribbons and showed an obvious increase in the specific surface area and the pore volume.     

Thermodynamic issues associated with combined cyclic voltammetry and wafer curvature measurements in electrolytes

A thermodynamic framework has been provided for the interpretation of combined cyclic voltammetry and surface stress measurements, the latter being obtained from wafer curvature or beam deflection measurements of a solid electrode as a function of applied potential (so-called voltstressograms). Firstly, the derivation of electrocapillarity equations for solid electrodes has been critically reviewed by starting from the Gibbs adsorption equation appropriate for solid–electrolyte interfaces. This allowed us to demonstrate the critical importance of elastic surface strain in the thermodynamic boundary conditions of the partial derivatives intervening in the interpretation of voltstressograms. From these considerations, it was shown for the first time that the electrocapillarity equations for solid electrodes are not appropriate for describing the variation of surface stress with potential obtained from wafer curvature measurements, because such measurements are intrinsically incompatible with the constant strain condition implied in the electrocapillarity equations. An alternative explanation is provided for the experimentally observed proportionality between the current density, measured in cyclic voltammograms, and the first derivative of surface stress with respect to potential, obtained from voltstressograms.     

On the modification of solid adsorbents with volatile organics II. The role of the layer adsorbed

Summary This paper presents a continuation of our research dedicated to solid-adsorbent surface modification with what are commonly regarded as volatile and easily eluted organic compounds. Two porous adsorbents were used: natural zeolite (clinoptilolite) and alumina, while the adsorbates employed were n-hepatane and benzene. The results show that a simple injection of volatile adsorbate greatly alters the solid surface adsorption properties. The consequences of volatile modifier application are discussed on the grounds of adsorption isotherms determined at 313K. Possible implications to the tailor made adsorbents are outlined as well.Part I, J. Chromatogr.442, 105 (1988)     

Studies on the properties of ionic liquid EMIInCl4

This paper reports that an ionic liquid (IL) has been prepared by directly mixing InCl₃ and 1-methyl-3-ethylimidazolium chloride (EMIC) with molar ratio 1/1 under dry argon atmosphere. The densities, and surface tension of the pure IL were determined at temperature range of 293.15 to 343.15 ± 0.1 K. The volumetric properties and the properties of surface for ionic liquid based on group III were discussed by Glasser's theory and Yang's interstice model.     

Immobilization of antibody fragment for immunosensor application based on surface plasmon resonance

Biosurface fabrication using the Fab′ fragment of immunoglobulin (IgG) was carried out by self-assembly (SA) technique. The pepsin-digested monoclonal antibody (Mab) against bovine insulin containing the F(ab′)₂ fragment and residual proteins was separated using affinity chromatography and dialysis. To prevent the nonspecific binding of F(ab′)₂ onto gold (Au) substrate, the native disulfide bridge was reduced using dithiothreitol (DTT) to convert F(ab′)₂ into Fab′, which made the immobilization to be carried out via the native thiol (–SH) group. The fabricated biosurface using SA technique showed the formation of stable thin film through AFM topography. Through the concentration change of DTT and Fab′, the absorption characteristics against the Au surface were investigated using surface plasmon resonance (SPR) with the flow cell. The amount of immobilized antibody fragment and the antigen binding capacity were regulated with respect to the reduction state and concentration of F(ab′)₂. Based on the biosurface of the fabricated Fab′, the insulin-detection was carried out by the measurement of SPR. The proposed antibody surface could successfully detect the bovine insulin at the concentration from 100 ng/mL to 10 μg/mL.     

Identification of defect sites on oxide surfaces by metastable impact electron spectroscopy

In this review, thin films of SiO₂ on Mo(1 1 2) and MgO(1 0 0) on Mo(1 0 0) have been characterized using metastable impact electron and ultraviolet photoelectron spectroscopies (metastable impact electron spectroscopy (MIES) and ultraviolet photoelectron spectroscopy). The electronic and chemical properties of the thin films are identical to those of the corresponding bulk oxides. For different prepared defective SiO₂ surfaces, additional features are observed in the band-gap region. These features arise from vacancies or excess oxygen and are consistent with theoretical predictions of additional occupied states in the band-gap due to point defects. Extended defect sites on SiO₂ and MgO are identified using MIES by a narrowing of the O(2p) features with a reduction in the density of extended defect sites. MIES of adsorbed Xe (MAX) is also used to estimate the density of extended defect sites. Furthermore, it is shown that CO is an appropriate probe molecule for estimating the defect density of MgO surfaces. Upon Ag exposure, the change in the work function of a low defect MgO(1 0 0) versus a high defect surface is markedly different. For a sputter-damaged MgO(1 0 0) surface, an initial decrease of the work function was found, implying that small Ag clusters on this surface are electron deficient. In contrast, for SiO₂ no significant change of the work function upon Ag exposure with increasing defect density was observed. On MgO(1 0 0), the presence of defect sites markedly alter the electronic and chemical properties of supported Ag clusters. Such a strong influence of defect sites was not found for Ag clusters on SiO₂.     

Incorporation conditions guiding the aggregation of a glycosylphosphatidyl inositol (GPI)-anchored protein in Langmuir monolayers

This work investigates the process of incorporation of a glycosylphosphatidyl inositol (GPI)-anchored alkaline phosphatase into Langmuir monolayers of dimyristoyl phosphatidic acid (DMPA). Three different methods of protein incorporation were assayed. When the protein solution was injected below the air–water interface after formation of the lipid monolayer a micro-heterogeneous distribution of alkaline phosphatase throughout the interface was observed. Adsorption kinetics studied by fluorescence microscopy, associated with surface pressure measurements, led to the proposition of a model in which the protein penetration is modulated by the surface packing of the monolayer and intermolecular interactions occurring between the phospholipid and the protein. At initial surface pressures higher than 20 mN m⁻¹, the protein is quickly adsorbed on the interface and the lateral diffusion drives the alkyl chains to turn towards the air phase while the polypeptide moiety faces the aqueous subphase.     

XPS定量分析及其在CdTe（Ⅲ）面识别化学物种中的应用

我们用谱仪能量传输函数修正的相对原子灵敏度因子获得了ＸＰＳ定量数据。通过将定量结果与结合能的化学位移相结合的方法，分析了ＣｄＴｅ表面的两个氧化过程，结果表明，机械抛光样品表面的构成是：６６％ＣｄＴｅ，２８．９％的Ｃｄ（ＯＨ）２和５．１％ＴｅＯｘ（Ｘ＞２），而经化学抛光的表面构成是∶８４．４％的ＴｄＴｅＯ４和１５．６％ＴｅＯｘ（Ｘ＞１）。     

Application of ammonia intermittent temperature-programmed desorption to evaluate surface acidity of tungsten oxide supported on activated carbon

Intermittent temperature-programmed desorption of ammonia was used to study the strength and population of surface acid sites of tungsten oxide supported on activated carbon pretreated at 350 and 700 degrees C. Catalysts pretreated at 350 degrees C showed two types of surface acid sites and desorption occurred with free readsorption until a temperature of around 300 degrees C was reached. Pretreatment at 700 degrees C produced three different states of ammonia adsorbed on the catalysts and desorption occurred with free readsorption.