熔融碳酸盐燃料电池阳极材料表面改性

选择铌作为合金化元素，通过氟化物熔盐电化学表面合金化的方法对熔融碳酸盐燃料电池阳极材料镍进行表面改性，改性后的阳极材料的耐蚀性能与电催化性能均得到明显的改善。     

The physicochemical surface characteristics of Brevibacterium linens

The physicochemical surface characteristics and interfacial behavior of two strains of Brevibacterium linens (BL-MGE and BL-9174), that may enhance cheese flavor, were assessed. Cell surface hydrophobicity was determined by measuring the contact angle of a variety of polar and non-polar wetting agents on lawns of the bacterial cells. The contact angles obtained were used to calculate the cell surface free energy components γ^LW, γ^AB, γ⁺ and γ⁻. The Lifshitz van der Waals component and the Lewis acid-base component were approximately 35 mJ m⁻² and 22 mJ m⁻², respectively, for both strains. Under conditions of physiological pH and low ionic strength, neither strain exhibited affinity for an octyl ligand in hydrophobic interaction chromatography. This occurred despite a favorable free energy of interfacial interaction which was attributable almost entirely to favorable acid-base interactions between cells and octyl-sepharose. The nature of surface functional groups was evaluated using X-ray photoelectron spectroscopy. Excluding H, the mean percentage of atomic fraction for C, O, N and P for BL-MGE was 57.7, 37.8, 3.9 and 0.6%, respectively and 61.0, 31.8, 7.0 and 0.2%, respectively for BL-9174.     

Probing the surface polarity of native celluloses using genuine solvatochromic dyes

The surface polarity of native celluloses has been investigated by the following solvatochromic dyes: dicyano-bis (1,10)-phenanthroline iron (II) Fe(phen)2 (CN)2 (1), bis(4-N,N-dimethylamino)-benzophenone (2), and cou-marine 153 (3). Linear Solvation Energy (LSE) relationships and the UV/Vis data have been used to characterize the surface polarity of different native cellulose batches in terms of the empirical Kamlet–Taft polarity parameters (hydrogen bond acidity), (hydrogen bond basicity), and * (dipolarity/polarizability). , , *and calculated Reichardt's E T (30) values are reported for various native and regenerated cellulose samples with different degrees of crystallinity. The degree of crystallinity of the cellulose samples has been determined by X-ray. The microcrystalline environment of cellulose can be exactly parameterized in terms of the , and *values. It shows a fairly strong acidity and a low dipolarity/polarizability. For the amorphous sections smaller and larger * values are observed. The correspondence of the empirical polarity parameters determined has been discussed in relation to results from pyrene fluorescence and zetapotential measurements.     

A new approach to the design of surface treatments for reinforcing agents

A new approach for design of improved interfacial bonding between carbon fibers and polymeric matrices is described. In this method the affinity of surface-treated carbon fibers to various polymer matrices is simulated by analyzing the adsorption characteristics of model compounds, typical of the polymer units, onto very high surface area carbon fibers. The affinity can be evaluated by the use of Thermogravimetric Analysis (TGA) to measure adsorption–desorption characteristics. Since high surface area, activated carbon fibers (ACF) can be chemically treated to obtain acidic, basic, nonpolar or highly polar surfaces, it should be possible to assess the interactions of chemically modified surfaces with model compounds such as methanol (MeOH), acetone, dimethylformamide (DMF), dimethylether, tetrahydrofuran (THF) and water. Some preliminary results are presented, indicating that surface treatments for carbon fibers other than oxidation may lead to enhanced bonding with polymeric matrices.     

偶联剂对钛酸钾晶须/双马来酰亚胺树脂摩擦磨损性能的影响

研究了不同偶联剂及钛酸钾晶须添加量对钛酸钾晶须 /双马来酰亚胺树脂复合材料的摩擦磨损性能的影响 .结果发现 ,钛酸钾晶须能明显提高复合材料的耐磨性 ,晶须的加入使材料的磨损率得到显著降低 ;钛酸钾晶须对材料具有一定的润滑性 ,添加晶须后材料的摩擦系数与树脂基体基本相当 ;偶联剂对复合材料的摩擦系数影响不大 ,但是合适的偶联剂对材料耐磨性的提高则具有明显的作用 .晶须添加量较低时 ,复合材料的磨损机理主要为较严重的粘着磨损 ,晶须添加量较高时 ,疲劳磨损占主导地位 .     

A micro-scale method employing surface plasmon resonance detection for the determination of conditions for immunoaffinity chromatography of proteins

Summary The BIAcore^TM Biosensor System utilizes a detection principle known as Surface Plasmon Resonance (SPR) which, in simple terms, detects changes in the refractive index of a solution in contact with a gold film. The gold film is surface modified with carboxymethylated dextran to produce a hydrophillic matrix onto which macromolecules may be covalently immobilized. In this respect, the BIAcore^TM is similar to any other insoluble matrix, such as a chromatographic support. The SPR detection principle, however, allows one to directly visualize the interaction under study, in real time and without the need for reporter molecules such as enzyme-labels. In addition, the very small sample requirements, automated robotics unit and ease of data analysis suggest the potential use of the BIAcore^TM instrumentation for assay development and possibly process development, especially where bio-specific interactions such as immunoaffinity chromatography are used as a step in the process. In this report, we demonstrate the use of the BIAcore^TM SPR detector for the micro-scale determination of conditions for immunoaffinity chromatography of soluble complementreceptor 1, sCR1.     

等离子体辐照的聚乙烯表面接枝交联共聚合

聚合物利用低温等离子体预辐照进行表面接枝共聚合已有报道.此方法的优点是接枝层被限制在聚合物表面,辐照过程对基材本体性质无影响,且整个过程对环境无污染. 用等离子体使聚合物表面产生自由基,不需要表面具有不饱和键或特殊官能团,因而适用于任何聚合物,甚至于一些无机物如玻璃等.利用等离子辐照后暴露于空气的聚合物表面上生成的过氧自由基或过氧化物进行接枝反应,一般接枝量不大.本工作中,我们自己设计了反应器,以超高分子量聚乙烯(UHMWPE)为基材,以甲基丙烯酸甲酯(MMA)为接枝单体,在无氧条件下利用等离子体辐照产生的表面自由基进行了接枝聚合,产物接枝量高达10％.还用顺磁共振技术对表面自由基性质及其在接枝过程中的行为进行了跟踪研究.     

Modification of polysulfone membranes 4. Ammonia plasma treatment

The effect of NH₃ and NH₃/Ar plasma on ultrafiltration polysulfone membranes have been studied. Results of contact angle, FTIR-ATR and X-ray photoelectron spectroscopy experiments clearly showed that both plasmas introduced hydrophilic, nitrogen- and oxygen-containing moieties on the polymer surface and that NH₃/Ar plasma was more efficient. That plasma was also more aggressive--signs of strong etching could be seen on the SEM pictures. Redeposition of etched material seemed to take place inside the pores. On the contrary, ammonia plasma was soft and caused cleaning the surface and pores enlargement. Performance of ammonia plasma modified membranes was greatly improved and independent on solution pH. The last observation proved amphoteric character of the surface. NH₃/Ar plasma treatment gave membranes of acidic surface and filtration indices not so good as for ammonia plasma.     

Resistance to Surfactant and Protein Fouling Effects at Conducting Diamond Electrodes

Boron‐doped diamond thin‐film electrodes display negligible fouling effects in the presence of high levels of surface‐active materials, including proteins. Dramatic improvements in the stability of the analyte response (compared to common glassy carbon and carbon paste electrodes) are illustrated using bovine serum albumin (BSA), gelatin, and Triton X‐100 in connection with repetitive square‐wave voltammetric (SWV) measurements. The voltammetric response of ascorbic acid at the diamond electrode exhibits negligible shifts in peak potentials and minimal depressions of current signals over a wide range of surfactant concentrations (0–750 ppm). For example, the diamond electrode exhibited 70, 50 and 60 mV potential shifts for 10 repetitive voltammetric scans in the presence of 100 ppm BSA, gelatin and Triton X‐100, respectively, compared to 120, 190, and 280 mV shifts observed at the glassy carbon electrode. Furthermore, only 4.3 and 6.2% of the initial current decays were observed in the presence of 100 ppm Triton X‐100 and gelatin, respectively (compared to 45.2 and 34.4% diminutions at the glassy carbon electrode). Such improved performance was also confirmed from the SWV measurements of uric acid, dihydroxyphenylacetic acid, and catechol. The greatly improved resistance to surfactant interference reflects the fact that the as‐grown diamond thin film, composed of oxide‐free and hydrogen‐terminated surface, has a relatively lower surface energy and minimal electrostatic attributes, either specific or general, so that little adsorption of surface‐active agents occurs. The topographic AFM images of the diamond electrode surface confirm a negligible BSA fouling effect after repetitive SWV measurements. Such enhanced antifouling features make diamond electrodes very attractive for numerous real‐life electroanalytical applications.