高分子介质对银盐扩散转移过程的影响

分散在高分子介质中的物理显影核层作为影像接受层,是CTP版材的重要组成部分.本文采用线阵CCD及银量测定法研究了三种高分子作为物理显影核的介质对物理显影过程及版材性能的影响.结果表明,PVA-Ⅰ、PVA-Ⅱ减慢扩散转移过程并降低版材的反差,而PVP对扩散转移过程有轻微促进作用.此外还用扫描电镜方法观察了物理显影银的表面堆积状态,发现银堆积状态与介质的种类及涂布量有关.     

银盐CTP版材物理显影过程及银堆积形态的研究

银盐扩散型CTP(Computer-To-Plate)版材基于银盐扩散转移原理.本文利用高分辨率的场效应扫描电子显微镜及CCD等手段研究了几种因素对该类版材物理显影银堆积状态及物理显影过程的影响.清晰地观察到不同曝光区物理显影银的堆积状态,在弱曝光区,银颗粒堆积紧密,是版材具有亲油性的主要原因.使用不同类型络合剂分别得到了颗粒状、树枝状等各种形态的物理显影银,表明络合剂对银颗粒形态有显著影响.通过CCD装置对版材上物理显影过程的实时原位监测,从动力学的角度解释了络合剂、显影温度对物理显影银堆积状态的影响.     

硫醇修饰Fe_3O_4@SiO_2@Ag SERS基底检测氨苄西林

制备了一种烷基硫醇修饰的磁性纳米银SERS基底,对氨苄西林(AMP)进行了拉曼检测,并考察了不同的硫醇修饰磁性纳米银基底对AMP的增强效果。采用不同烷基链长的硫醇对磁性纳米银SERS基底进行修饰,通过分子的自组装,使烷基硫醇自发的生长在磁性纳米银的银壳表面,通过疏水作用,使AM P分子富集于基底的表面,以达到AM P分子拉曼信号增强的检测目的。实验结果表明,3种不同烷基链长的硫醇修饰的基底对AMP的拉曼增强效果依次是正丙硫醇正己硫醇正壬硫醇。正丙硫醇修饰的基底对AMP盐酸溶液的检出限为0. 1 nmol/L。通过硫醇修饰的磁性纳米银基底能够富集AMP分子,可用于低浓度检测。     

用铜物理显影的多级放大成像过程Ⅲ.影像中铜和银的分布及明胶对Au3+的还原

本文研究了铜物理显影后影像中铜和银的分布以及在非影像区明胶对Au³⁺的还原作用。铜含量随着影像深度的增加而增加,银含量却随着深度的增加而减少。Ag3d结合能向低值位移说明影像内部的银处于单原子和多原子的混合状态,但是影像表面的银却为单原子状态,如果铜物理显影进行得足够长,铜最终会将银全部遮盖。在这以后的铜物理显影是铜的自催化过程,样片浸入氯金酸溶液中后,非影像区中吸收的氯金酸量大大高于影像区,因而铜的沉积速度在非影像区也比影像区大得多。明胶能还原Au³⁺.还原过程可分为两步:第一步由Au³⁺还原成Au⁺,这一步在室温下是快反应;第二步由Au⁺还原成金,这个反应比较慢,Au⁺和Au在物理显影中可作为催化核,使铜在非影像区沉积。     

超疏水碱式碳酸钴纳米线薄膜的制备及抗腐蚀性

以镍为基底,采用水热法在其表面制得碱式碳酸钴纳米线薄膜,用十二烷基硫醇进行表面修饰后其表现出超疏水性,水滴在其表面的接触角达到152.3°,滚动角接近5°.研究结果表明,薄膜表面微纳米阶层结构及低表面物质的协同作用使其呈超疏水性.与普通镍片和硫醇修饰前的碱式碳酸钴纳米线薄膜相比,超疏水碱式碳酸钴纳米线薄膜具有更好的抗腐蚀性.相关研究有望为超疏水金属表面的制备及其抗腐蚀性研究提供思路.     

透明抗静电多功能超疏水薄膜的制备

采用提拉法在聚酰亚胺薄膜表面分步涂覆了银纳米线及疏水纳米二氧化硅, 分别构筑了导电网络及超疏水涂层, 制备了超疏水抗静电透明薄膜. 研究结果表明, 超疏水抗静电透明薄膜保持了较高的透光性, 其透光率高于90%. 同时, 银纳米线网络的构筑有效增加了超疏水抗静电透明薄膜的导电性, 使其表面电阻介于10⁶~10¹⁰ Ω之间, 达到了抗静电要求. 水滴在该薄膜表面静态接触角高达156.4°, 滚动角小于1°, 展现了优异的超疏水特性. 通过导电网络及疏水涂层的构筑, 实现了透明及抗静电超疏水多功能的统一.     

烟酸在热敏成像材料中的调色作用

本文将烟酸引入以硬脂酸银为银源的热敏成像材料中,可以明显提高显影密度,并使影像颜色由金黄色变成黑色;同时显影银粒子的尺寸变大、形貌也会发生改变,并且显影银粒子像链珠一样排成一条线,而线与线之间基本上是平行排列的.进一步实验结果表明,烟酸的引入会降低材料的pH、pAg值和银盐的相变温度,硬脂酸银与烟酸一起加热可能反应生成了新的化合物.     

铁表面银纳米粒子自组装膜及其缓蚀性能研究

应用化学还原法于水溶液中制备银纳米粒子.在十二烷基硫醇的保护下,将银纳米粒子从水相转移到甲苯相,并将处理好的铁电极浸泡在含有十二烷基硫醇保护的银纳米粒子/甲苯溶液中,制得十二烷基硫醇/银纳米粒子自组装混合膜.电化学方法如交流阻抗谱(EIS)、极化曲线等研究该自组装膜在0.5 mol.L-1H2SO4溶液中的缓蚀作用.XPS测试证实该自组装膜十二烷基硫醇和银纳米粒子之存在.     

硫醇-烯点击化学法制备C18毛细管电色谱开管柱及其性能研究

基于十八烷基硫醇与乙烯基功能化毛细管(Vinyl capillary)的硫醇-烯点击化学反应,制备了一种新型的C18毛细管电色谱开管柱(C18capillary).采用乙烯基三甲氧基硅烷对毛细管内壁进行乙烯基功能化,然后通过硫醇-烯点击化学反应共价键合十八烷基硫醇于Vinyl capillary内表面.采用环境扫描电镜对C18 capillary进行了形貌表征.考察了缓冲溶液pH值对C18 capillary、Vinyl capillary和裸毛细管柱(Bare capillary)电渗流的影响.结果表明;在相同实验条件下,C18capillary的电渗流最小.以3种多环芳烃为模型化合物,评价了C18capillary的电色谱柱性能;同时考察了模型化合物在C18capillary上的电色谱保留行为.实验表明,其保留机理是基于典型的反相作用.当C18 capillary用于碱性模型化合物分离时,碱性物质在C18 capillary上的峰形较好,无明显的峰拖尾现象,这可能是由于C18capillary表面含有极性的S基团能够屏蔽残留硅羟基对碱性化合物的吸附作用.     

显影灰雾形成机理的研究 Ⅰ.显影灰雾形成过程的受阻显影研究

本文利用受阻显影和电镜方法,对比了显影灰雾与乳剂灰雾的形成过程.研究表明,乳剂灰雾是由于在乳剂制备过程中形成的灰雾中心而引起的,这种灰雾中心在显影过程中的行为与潜影中心一样,显影在少数中心开始,最后生成丝团状银.显影灰雾的形成则经过成核和生长两个不同的阶段:藉显影物分子与乳剂颗粒表面的碰撞而生成银核,一旦稳定的银核生成,随后就能以较快的速率继续生长.因此在一般显影的条件下,显影灰雾的形成需要一个较长的显影引发期.成核在颗粒表面的许多部位发生,同时生长,最后生成紧密的银块.溴化钾和季铵盐对成核速率有显著影响,这表明了乳剂颗粒表面负电荷在显影成核阶段中的作用.未敏化乳剂的显影灰雾中心在颗粒表面上的分布是随机的,而硫敏化乳剂的显影灰雾中心则优先在八面体的棱上生成.     

免处理型CTP版材研究进展

根据1999-2002年公开的专利,评述了这几年间免处理CTP版材研制开发的内容:1)水处理型;2)附加型;3)形态变化性;4)相变化型.免处理版材被认为是今后CTP版材,尤其是热敏CTP版材发展的方向.但免处理版材若想在实际中推广应用,还有许多问题需待研究解决.     

Interfacial and molecular properties of high-pressure-treated beta-lactoglobulin B

Interfacial properties of beta-lactoglobulin B subjected to hydrostatic pressures up to 400 MPa were studied by measuring surface pressure at the air/water interface and the elastic interfacial shear modulus at the oil/water interface. The surface hydrophobicity of pressurized beta-lactoglobulin was determined by an 1-anilino-naphthalene-8-sulfonate assay and exposure of free thiol groups using the Ellman assay. The molar mass of pressure-induced oligomers was measured using a combination of size exclusion chromatography, light scattering, and refractive index measurements. High-pressure treatment of beta-lactoglobulin increased the surface pressure growth rate and its final level at the air/water interface. After high-pressure treatment, the maximum interfacial elasticity at the oil/water interface increased, and the time lag before growth of the interfacial elasticity decreased. Up to 200 MPa, large amounts of monomeric beta-lactoglobulin were formed with increased exposure of thiol groups and increased surface hydrophobicity compared to unpressurized beta-lactoglobulin. At a pressure higher than 200 MPa, surface hydrophobicity continued to increase, while exposure of thiol groups decreased, the latter due to the formation of covalently linked oligomers. We have shown that surface hydrophobicity rather than thiol exposure is important for the pressure-induced increase in growth rate and the final level of surface pressure at the air/water interface and in interfacial elasticity at the oil/water interface.     

Existence of a hydrophobic gap at the alkanethiol SAM-water interface: an interfacial capacitance study

The highly hydrophobic neat alkanethiol-coated SAM on evaporated gold shows an unusually low interfacial capacitance in aqueous media. This result cannot be explained by a simple parallel plate model of the double layer with the alkanethiol monolayer as a sole dielectric separator. Interestingly, a hydrophilic SAM prepared from a neat hydroxy thiol does not show any such capacitance lowering in aqueous media. Our results suggest the existence of a "hydrophobic gap" between the alkanethiol SAM-water interface. Such a model is also very much consistent with the predictions of Lum, Chandler, and Weeks theory of length scale dependent hydrophobicity.     

Electrical property and water repellency of a networked monolayer film prepared from Au nanoparticles

Gold nanoparticles, modified with alkyl thiol, formed a film on polystyrene substrate, and it was found that the deposited film drastically changes its conductivity and hydrophobicity, depending on the alkyl chain length of the thiol used.     

离子交换树脂吸附胞嘧啶核苷三磷酸的动力学和热力学研究

根据CTP在离子交换树脂上的吸附容量和分离因数的大小,确定Duolite A-30树脂适合CTP与CDP及CMP之间的分离.CTP在Duolite A-30树脂上的吸附动力学和热力学研究表明,在283.15～303.15K之间,CTP的质量浓度在7.5g/L以上时,Duolite A-30树脂对CTP的吸附主要受颗粒扩散的控制,其有效扩散系数为D=3.47×10-7cm2/s,溶液的质量浓度≤1.0g/L时,CTP与Duolitc A-30树脂之间的交换速率主要受液膜控制,其液膜扩散系数为Kf=4.112×10-4/s.热力学参数Eα=9.008kJ/mol,△H=5.17kJ/mol·K,△S283.15K=80.28J/mol·K.     

Simple Biosensor with High Selectivity and Sensitivity: Thiol‐Specific Biomolecular Probing and Intracellular Imaging by AIE Fluorogen on a TLC Plate through a Thiol–Ene Click Mechanism

A handy, specific, sensitive bioprobe has been developed. Tetraphenylethene (TPE) was functionalized by a maleimide (MI) group, giving a TPE‐MI adduct that was nonemissive in both solution and the solid state. It was readily transformed into a fluorogen showing an aggregation‐induced emission (AIE) property by the click addition of thiol to its MI pendant. The click reaction and the AIE effect enabled TPE‐MI to function as a thiol‐specific bioprobe in the solid state. Thus, the spot of TPE‐MI on a TLC plate became emissive when it had been exposed to L ‐cysteine, an amino acid containing a thiol group, but remained nonemissive when exposed to other amino acids that lack free thiol units. The thiol‐activated emission was rapid and strong, readily detected by the naked eye at an analyte concentration as low as approximately 1 ppb, thanks to the “lighting up” nature of the bioprobing process. Similarly, the emission of TPE‐MI was turned on only by the proteins containing free thiol units, such as glutathione. Clear fluorescence images were taken when living cells were stained by using TPE‐MI as a visualization agent, affording a facile fluorescent maker for mapping the distribution of thiol species in cellular systems.     

连苯三酚缩二乙烯基苯树脂活性醚化物的合成与成像应用

通过乙烯基乙醚和连苯三酚缩二乙烯基苯树脂( PDVB resin)的羟基加成,合成了具有缩醛结构的活性醚化物,并对该活性醚化物的合成条件进行优化.这种具有缩醛结构的活性醚化物具有常温酸解和热解性能,作为阻溶促溶剂可用于常温化学增幅阳图感光成像和阳图热敏成像中.用于阳图热敏CTP感热成像配方中,使得版材具有高感度、高抗碱性、高稳定性;用于阳图CTcP感光成像配方中,使得该版材的综合成像性能优良;用于正性光致抗蚀剂成像配方中,使得该正性光致抗蚀剂具有高感度和高分辨率.     

脱晶蒽油改质煤焦油沥青的研究——中间相非等温动力学

在热转化装置上,对宝钢Ⅰ期焦油沥青（简称I－CTP）及其添加18％、30％脱晶蒽油（简称DCAO）制成的软沥青进行了中间相转化非等温动力学研究,采用积分法求得了有关动力学参数。结果表明,沥青中间相形成过程可以用一级反应来描述。宝钢Ⅰ期焦油沥青活化能为180.02kJ/mol。添加80％脱晶蒽油则提高了原料沥青的反应性,活化能为147.89kJ/mol,不利于优质中间相的形成。     

X-ray photoelectron spectroscopy and differential capacitance study of thiol-functional polysiloxane films on gold supports

Polymeric molecules containing multiple thiol groups (polythiols) provide tenacious attachment to metal surfaces such as gold. Polythiol films are also well suited for subsequent derivatization with biomacromolecules through remnant free thiol groups of the film. In this study, 1-3 nm thick layers of a commercial polythiol, poly((mercaptopropyl)methylsiloxane) (PMPMS), are investigated with X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy. XPS is used to reveal the surface coverage of thiolate-Au bonds between the polythiol and the metal support, which is found to be approximately 30% lower than that in alkanethiol self-assembled monolayers. The surface density of thiolate-Au bonds did not depend on film thickness provided sufficient PMPMS material was present. Differential capacitance measurements show that the effective dielectric barrier presented by PMPMS films under aqueous environments corresponds closely to their physical thickness, with even approximately 1 nm films remaining impermeable to electrolyte species. Modification of the films with an oligoethylene glycol compound was also examined, in anticipation of future applications in label-free, impedance-based biomolecular diagnostics.