聚丙烯中空纤维膜的微孔结构的控制

通过熔纺／冷拉伸法制备了微孔聚丙烯中空纤维膜。研究了工艺条件对微孔聚丙烯中空纤维膜的微孔结构与性能的影响。结果表明：随着纺丝温度的下降或熔体拉伸比的提高，最大可几孔径及孔隙率增大；熔纺中冷却风速提高，最大可几孔径及孔隙率较大；温度低于110℃时，热处理对最大可几孔径及孔隙率的影响较小，在120－130℃时，随着热处理温度的增加，最大孔径及孔隙率有明显增加的趋势；随着初纺中空纤维拉伸倍数的增加，孔隙率先增加而后下降。     

Synthesis of polypiperazine-amide thin-film membrane on PPESK hollow fiber UF membrane

A new interfacial polymerization (IP) procedure is developed in order to synthesize polypiperazine-amide thin-film membrane on the inner surface of poly(phthalazinone ether sulfone ketone) (PPESK) hollow fiber ultrafiltration (UF) membrane.A hollow fiber composite membrane with good performance was prepared and studied by FT-IR and scanning electron microscopy.     

化学发光消耗型锰传感器

化学和生物发光是由化学反应产生的一种光辐射,不需要任何光源。又由于它们具有高灵敏度、宽线性范围和相对比较便宜的仪器等优点,因而在化学和生物传感器领域引起了广泛的兴趣。已用于H_2O_2、乳酸和胆固醇等多种生物活性物质的测定,但未见有金属离子传感器的报道。本文发展了一种新型的全固态模式的消耗型锰离子化学发光传感器。该传感器将除待测物外的所有化学发光反应试剂全部固定在阴离子交换树脂Amberlyst A-27上,于化学发光反应之前,将一定量化学发光试剂从固定化试剂柱上洗脱,与样品中的锰离子产生化学发光。已成功地应用于水样中痕量锰离子的测定。每个固定化试剂柱可连续使用100次以上。 1 实验部分 1.1 仪器和试剂 化学发光传感器由流动系统和检测系统两部分组成。其中流动系统主要由蠕动泵、六通阀、固定化试剂柱和流通池组成。检测系统由光电信增管、负高压、放大器和记录仪组成(图1)。     

动力学—压电石英晶体传感器测定水中微量汞的研究

基于涂银压电石英晶体对ＣＮ＾－离子的灵敏响应，应用汞对六氰合铁酸钾与邻二氮杂菲反应的动力学催化作用，建立了动力学－ＰＱＣ传感器单面触液测定微量汞的新方法。研究了ＰＱＣ传感器对汞的响应机理，响应曲线，实验条件及共存离子干扰情况。     

固相微萃取/二氧化锡气体传感器联用技术对果蔬中有机磷农药残留的快速检测

研究了固相微萃取(SPME)和二氧化锡气体传感器的联用技术对果蔬中有机磷农药残留乐果、氧乐果、甲胺磷、乙酰甲胺磷、马拉硫磷、敌百虫等的快速检测。结果表明，在85℃下，解吸8min，二氧化锡气体传感器在2min内完成对有机磷农药残留的快速检测。零解吸时间测量的甲胺磷的动态响应曲线表明。SPME／二氧化锡气体传感器联用技术对分析SPME的解吸平衡非常有利。     

ORGANIC CHELATING REAGENT ON REDOX ADSORPTION OF ACTIVATED CARBON FIBER TOWARDS Au^3+

Organic chelating reagent influences upon the redox adsorption of activated carbon fibertowards Au3- were systematically investigated. The experimental results indicated that the presenceof organic chelating reagent on activated carbon fiber strongly affects adsorption capacity ofactivated carbon fiber towards Au3+. The reduction-adsorption amount of Au3+ increased three timesby the presence of 8-quinolinol. Furthermore, The reduction-adsorption amount of Au3+ depended onthe pH value of adsorption and temperature.     

PBO纤维的合成及其微观结构

聚对苯撑苯并双唑 (PBO)纤维是一种高强度、高模量、高热稳定性、高耐化学腐蚀性的新型纤维。着重介绍了PBO纤维的合成工艺、纺丝工艺 ;并对PBO的微观结构形态和表征方法进行了综合评述。     

Tumor cell detection method using complement-mediated cytolytic reaction and imaging sensor system

A novel tumor-detection system consisting of complementmediated cytolytic reaction and an image processing system was developed for the simple and rapid determination of tumor cells. The present system consists of a CCD image sensor, image memory board, personal computer, and microscope. When monoclonal antibody 3C4, which is specific to the guinea pig hepatoma L-10, was added to cell suspension, only L-10 cytolysis occurred. Cytolysis caused a decrease in brightness of the cells observed by phase-contrast microscopy. The phase contrast image of the cells before cytolysis was converted to a digitalized signal and stored in computer memory. After cytolysis, a brightness threshold above that of lysed cells was subtracted from the digitalized signal and compared to the signal stored before reaction. L-10 cells in mixed cell suspension were determined specifically by the system. Measurement time was only 2 sec and overall time, including reaction time, was approximately 30 min. Since this method does not require a cell washing process, automation of the whole system is possible.     

Electrokinetic and contact angle measurements of grafted carbon fibers

 The grafting method that has successfully been applied to methacrylic acid and liquid crystalline monomers was expanded to prepare amphoteric carbon fiber surfaces using 2-(N,N-dimethylamino)ethyl methacrylate as monomer. The obtained carbon fiber surfaces were characterized by contact angle and ζ-potential measurements. The expected basic behavior was not observed, instead an amphoteric character of the modified carbon fiber surface was found. The fiber surfaces display a basic character in the acidic pH-range, while they are acidic in the alkaline part of the pH-scale. An important influence is derived from the amount of initiator used to graft the monomers onto the fibers. The smaller the initiator concen-tration used during polymerization, the larger the amount of amino functionalities introduced to the carbon fiber surface. The wetting behavior versus water depends on the overall conformation of the immobilized polymer. During immersion into water the polymer acts hydrophobic, while during emersion, a hydrophilic character is observed, probably derived from conformational changes and swelling during the contact angle measure-ments in water. Received: 9 June 1998 Accepted: 13 August 1998     

Nonenzymatic Glucose Detection with Good Selectivity Against Ascorbic Acid on a Highly Porous Gold Electrode Subjected to Amalgamation Treatment

A nonenzymatic glucose sensor with good selectivity for the ascorbic acid oxidation is presented. After the gold polycrystalline electrode was subjected to amalgamation treatment, two advantageous effects were observed. One is the enhancement of the surface roughness and the other is an increase in the catalytic current in the glucose oxidation. Besides the known first effect, the latter provided another advantageous effect in a fabrication of nonenzymatic glucose sensor. Using a gold electrode subjected to amalgamation treatment for 60 s, two calibration curves for glucose oxidation at two different potentials of ?0.1 V and 0.25 V were obtained and compared. At the potential of ?0.1 V, at which no ascorbic acid was oxidized and no interference effect was observed, a current sensitivity of 16 μA cm^?2 mM^?1 from zero to 10 mM glucose concentration range was obtained. At the other potential of 0.25 V, at which ascorbic acid was easily oxidized, a satisfactory calibration curve with negligible ascorbic acid interference was also obtained together with a more enhanced current sensitivity of 32 μA cm^?2 mM^?1.