聚乙烯吡咯烷酮/AgNO3胶体用于激光诱导图形化化学镀铜

将聚乙烯吡咯烷酮(PVP)用于激光诱导化学镀的技术目前还鲜见报道。为此,对涂覆在聚酰亚胺(PI)上的PVP/AgNO3胶体用激光进行光刻还原出银纳米粒子,在PI表面实现了微米级的图形化化学镀。用AFM和XPS分别表征了激光辐射后银纳米粒子的形态和化学信息,用SEM分析了镀铜层的形貌以及激光扫描速度对镀层形貌的影响,并用半导体特性分析系统表征了镀层的I-E特性。结果表明,激光能有效地将PVP/AgNO3胶体中的Ag+还原成Ag纳米粒子,激光扫描速度小于0.1 mm/s时镀层比较均匀致密,且镀层与聚合物基体之间的粘结力好,镀层的选择性和导电性均良好。本方法为实现聚合物表面图形化化学镀开创了一条简单的、新的途径。     

杂环有机硅烷自组装膜为载体的ABS树脂表面镀铜

本研究通过在电晕放电处理的ABS树脂表面自组装6-(3-三乙氧基硅基丙基氨)-1,3,5-三嗪-2,4-二硫醇单钠盐(TES)薄膜后,进行化学镀铜研究。借助X-射线光电子能谱(XPS)、傅里叶变换红外光谱(FT-IR)、扫描电子显微镜(SEM)对ABS树脂、自组装薄膜及化学镀铜表面进行了表征,同时对化学镀铜做了粘接性能测试。结果表明:经TES自组装薄膜修饰后的ABS树脂表面呈现大量孔状结构,使ABS树脂表面的粗糙度增大,提高了ABS树脂与铜的结合力;化学镀铜后表面铜颗粒致密且均匀;盐水浸泡实验表明,经TES自组装薄膜修饰后的ABS树脂与铜层之间表现出良好的粘接特性。     

8-羟基喹啉金属有机聚合物自组装膜的均匀生长

采用自组装成膜技术在ITO表面制备了偶氮苯双8-羟基喹啉-金属螯合物薄膜，得到棕红色的均一薄膜。研究了不同层数、不同浓度、不同沉积时间和不同金属自组装薄膜的紫外吸收光谱，并且通过扫描隧道显微镜跟踪其沉积过程，证实自组装膜的沉积为均匀沉积过程。     

硅基底上图形化自组装膜的构筑

为在硅基底上得到不同化学基团修饰的图形,采用传统的光刻技术与自组装相结合的方法,成功地制备了由甲基与氨基末端官能团组成的图形化自组装膜。将图形化自组装膜泡入碳纳米管DMF(N,N-二甲基甲酰胺)分散液中,图形化自组装膜的氨基区域能均匀吸附一层分散液中碳纳米管,而甲基没有,表明图形化自组装膜的不同自组装膜区域的不同表面性质,证实了该方法的可行性。     

利用脉冲激光真空弧沉积技术制备类金刚石薄膜

介绍了一种新的脉冲激光真空弧沉积技术,利用该技术在硅基片上制备了类金刚石薄膜.利用激光拉曼分析技术对沉积膜进行了结构分析,结果表明沉积膜为非晶结构,具有明显的sp3结构特征.同时利用纳米划痕压痕仪、原子力显微镜等分析设备对膜的表面形貌、微观摩擦学性能进行了分析,结果表明Si<100>基片上沉积膜的表面形貌和微观摩擦学性能略优于Si<111>基片上沉积的薄膜,其摩擦系数平均值为0.036.     

BiFeO_3薄膜的液相自组装制备与表征

利用自组装单层膜技术,以三氯十八烷基硅烷(OTS)为模板,以硝酸铋和硝酸铁为原料,柠檬酸为络合剂,在玻璃基片上制备了铁酸铋晶态薄膜.探讨了薄膜的煅烧温度和沉积温度对BiFeO3薄膜的影响.通过X射线衍射(XRD)、扫描电镜(SEM)及原子力显微镜(AFM)测试手段对BiFeO3薄膜的物相组成、显微结构和表面形貌进行了表征,EDS能谱测试为铁酸铋薄膜的化学组成提供了有力的证据.结果表明:利用自组装技术在600℃热处理后成功制备出了纯净的BiFeO3晶态薄膜,当沉积温度为70～80℃时铁酸铋薄膜结晶良好,样品表面均匀、致密.     

纤维素/木质素微球抗紫外薄膜制备与性能研究

随着包装工业的快速发展和人类社会对环保要求的提高,功能性且可生物降解的包装膜材料越来越受到人们的重视.然而,目前市场上的可降解包装膜材料由于成本较高、力学性能差以及耐水性低而限制了其发展.采用自组装方法制备木质素微球,并将其沉积在纤维素膜表面,制备出一种新型纤维素基抗紫外薄膜材料.通过扫描电子显微镜(SEM)、红外光谱(FTIR)和激光共聚焦电子显微镜对薄膜的表面性能进行研究.利用抗张实验和紫外透光率测试对纤维素基功能薄膜的力学性能和抗紫外性能进行表征.结果表明:自沉积木质素微球在纤维素膜表面分布均匀,尺寸为1～2μm;纤维素薄膜疏水改性后有助于木质素微球的沉积,且沉积量随着木质素质量浓度的增加而增大.由于木质素微球的引入,纤维素复合膜的抗张强度比对照样增加22％,同时其对UVB屏蔽效果可达94％.     

空间柔性阵列天线薄膜阵面制造技术研究

简要阐述了空间柔性天线的进展，分析了空间柔性天线薄膜阵面制造关键技术。研究了薄膜阵面电磁波传输金属薄膜制备技术、薄膜阵面图形化制造技术、薄膜阵面拼接用材料评价、薄膜阵面的裁切技术等。采用磁控溅射技术，通过溅射功率、走带张力、走带速度的调节，在有机柔性薄膜基材上镀制了不同厚度的金属铜膜，实现了有机柔性薄膜基材的表面金属化；利用飞秒激光刻蚀精度高，不损伤柔性薄膜基材的特点，获得了图形化的金属薄膜阵面单元；对3M92号胶带与改性聚酰亚胺胶接材料的拼接强度与耐高低温性能进行了试验对比，发现改性聚酰亚胺胶接材料的强度与耐高低温性能更好，更适合薄膜阵面的拼接；对比了用纳秒激光和飞秒激光裁切的薄膜微观形貌，结果表明，用飞秒激光裁切的切面光滑，无烧蚀与毛刺，适合于高精度薄膜阵面的制造。研究为空间柔性阵列薄膜天线的制造提供了大量的基础数据。     

天然生漆膜的化学镀及其表征

以天然生漆膜为基材,利用化学镀技术在其表面化学沉积一层光亮的金属铜、镍、银等而获得生漆/金属复合膜材料,并用SEM(扫描电镜)、DMTA(动态热分析)、DSC-TG(热分析)及其他试验方法对镀层及其复合膜材料的性能进行了研究.结果表明,化学镀技术易在生漆膜表面实现金属化,镀层结合力强,金属粒径匀称、排布规整且致密;生漆/金属复合膜具有优良的动态力学性能,在25～360℃范围内,模量均在1×107～1×109Pa之间,具有优良的耐热性.     

微图形氧化钛薄膜表面内皮细胞生长行为研究

采用非平衡磁控溅射沉积技术制备微图形化的Ti-O薄膜,通过在微图形化的薄膜表面培养内皮细胞的方法,研究了微图形及表面物理化学性能对细胞生长行为的影响.结果表明,微图形尺寸减小到某一尺度范围之内会对内皮细胞在材料表面的生长起到接触引导作用,促进细胞在其表面生长;同时,表面成分、结构和表面能参数γsp/γsd也在一定程度上影响内皮细胞的生长行为.采用溅射技术使材料表面具有一定特征的表面微观形貌,能够引导和促进细胞在材料表面的生长,溅射技术制备微图形化表面可能成为等离子体生物材料表面改性的一个新的技术手段.     

A note on the use of ellipsometry for studying the kinetics of formation of self-assembled monolayers

Ellipsometry is currently one of the most important techniques for characterization of the deposition and growth mode of ultra thin organic films. However, it is well known that for thicknesses normally encountered in organic monolayer films, as would occur for example in self-assembled monolayers, ellipsometry cannot be used to simultaneously determine the thickness and refractive index of the monolayer film. Current practice is to assume a reasonable value for the film refractive index and calculate an effective ‘ellipsometric thickness’. This communication seeks to show that the alternative approach of assuming a thickness for the monolayer (determined by the length of the molecule) and calculating the effective film refractive index lends itself to easier and more meaningful physical interpretation. The Lorentz-Lorenz formula is then used to transform the effective refractive index into a surface coverage and hence to an effective mass coverage. The methodology advanced is applied to the kinetics of formation of a self-assembled monolayer of a well-studied molecule, octadecanethiol on Au.     

Preparation and tribological studies of self-assembled triple-layer films

A self-assembled triple-layer film was grafted onto a silicon surface with a simple three-step method. Firstly, 3-glycidoxypropyltrimethoxysilane molecules were self-assembled on silicon surfaces, then coupled to 3-aminopropyltriethoxysilane through a surface ring-opening reaction, and finally octadecyltrichlorosilane (OTS) molecules were attached to the resultant alkoxysilane-terminated surface via Si-O-Si bonds. The structure and morphology of this triple-layer film were characterized with various techniques, such as contact angle measurement, ellipsometry, X-ray photoelectron spectroscopy, and atomic force microscopy (AFM). The influence of different surface chemical groups on surface adhesion properties was identified using the AFM force-volume technique. The micro- and macro-tribological properties of the triple-layer film were evaluated by friction force microscopy and a ball-on-plate tribometer. The triple-layer film shows good adhesive resistance and can greatly reduce the micro- and macro-friction force. Moreover, compared to self-assembled monolayer of OTS, this triple-layer film exhibited much better wear-resistance. This improvement was mainly ascribed to the network structure of a lateral cross-linked polysiloxane layer formed within the film which can enhance the stability of the film.     

Use of attenuated total reflectance Fourier transform infrared spectroscopy to monitor the development of lipid aggregate structures

Attenuated total reflectance Fourier transform infrared spectroscopy is used to monitor the adsorption of 100 nm 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) phospholipid vesicles to the surfaces of Ge, electrolessly deposited Au, and a well formed self-assembled monolayer of 1-octadecanethiol. The interaction of DPPC vesicles in solution with these different surfaces yields distinctly different surface structures: intact DPPC vesicles on Ge, a supported phospholipid bilayer on an electrolessly deposited Au surface, and a phospholipid monolayer onto the hydrophobic self-assembled monolayer. IR peak position, bandwidth, and intensity are used to confirm structure formation and quantitation of the amount of lipid that desorbs during film formation.     

巯基-金自组装单层膜在生物分析检测领域的技术应用及缺陷与改进方法

随着生物分析检测技术的快速发展,对痕量物质的快速、超灵敏、高通量检测需求不断增多。其中,以巯基-金为基础构建的自组装单层膜分析技术作为超灵敏检测分析系统的重要组成部分,以其形成自组装膜方便、分析响应迅速、易于和其他分析方法联合使用等优点,已得到了广泛的应用。首先对巯基-金自组装单层膜原理进行简单介绍,并对其在生物分析测试中的应用进行分类总结,同时对应用中存在的一些缺陷和改进方案进行了探讨。希望通过从原理、应用、缺陷到改进方法的总结,对未来巯基-金自组装单层膜的设计和研究具有一定的指导意义。     

Nanometer-scale organic thin film transistors from self-assembled monolayers

A survey of the most interesting results on nanometer-scale organic thin film transistors (nano-OTFT) is presented. Additionally, we discuss our recent results on the properties of end-group functionalized organic self-assembled monolayers and on their use in the fabrication of nanometer-scale field-effect transistors. Nanometer-scale organic transistors (channel length 30 nm) were fabricated, with a self-assembled monolayer as gate insulator. The carrier transport in these transistors, as a function of the channel length, was investigated, and a transition from a dispersive to a ballistic transport at a channel length of 200 nm was observed. On a molecular scale, alkyl monolayers functionalized at their omega-ends by aromatic moieties were prepared. A high anisotropic conductivity in molecular insulator/semiconductor heterostructures of monolayer thickness was observed. These molecular architectures provide a basis for the building blocks of molecular transistors.     

Self-assembled monolayer of 3-aminopropyltrimethoxysilane for improved adhesion between aluminum alloy substrate and polyurethane coating

A good adhesion between a polymer coating and a metal or metal alloy substrate such as Al 2024-T3 plays a critical role in corrosion protection of metal substrates. In our study, a self-assembled monolayer film of 3-aminopropyltrimethoxysilane was formed on Al 2024-T3 substrate by covalent bonding. The adhesion property of a self-priming polyurethane coating was evaluated by pull-off adhesion test, wet tape test and thermal cycling test. All the testing results indicate that both dry and wet adhesion properties of the polyurethane coating were improved significantly after APS treatment of Al 2024-T3 in polar solvents such as methanol and acetone. In nonpolar solvents such as hexane, the APS treatment led to inconsistent improvement or sometime decreased adhesion of polyurethane coating. X-ray photoelectron spectroscopic study revealed that while a monolayer film was formed on the aluminum alloy surface after treating the substrate with APS in methanol and acetone, a multilayer film was formed on the substrate surface when the treatment was conducted in hexane. The APS monolayer film served as a covalent bond linkage between polymer coating and aluminum alloy substrates, which led to the increased adhesion property of polymer coating and corrosion resistance of the metal alloy substrate.     

Preparation, characterization, and photoelectric properties of a covalently self-assembled monolayer of ferrocenyl hemicyanine

A monolayer of a ferrocenyl hemicyanine was covalently self-assembled on an indium tin oxide (ITO)-coated glass substrate, and was characterized by UV/Vis absorption and X-ray photoelectron spectroscopy, and cyclic voltammetry. The photoelectrochemical properties and mechanism of photocurrent generation have also been studied. This monolayer film was found to exhibit a large anodic photocurrent density of 0.13 microA/cm2 with the highest photoelectric yield of 3.32% under irradiation of white light (730 nm > lambda > 325 nm) at a bias potential of +0.4 V versus saturated calomel electrode.     

Optical properties of an octadecylphosphonic acid self-assembled monolayer on a silicon wafer

We report a study of a full-coverage octadecylphosphonic acid (OPA or ODPA) self-assembled monolayer (SAM) spin-coated on the native oxide layer (SiO₂) of a single crystalline silicon (c-Si) wafer using spectroscopic ellipsometry (SE) and reflectometry (SR). The OPA SAM showed characteristics of being a dielectric film in visible range and becoming absorbing in deep-UV range. By assuming an optical stack model of OPA/SiO₂/c-Si for the OPA monolayer system and adopting the parameterized Tauc-Lorentz dispersion model, we obtained an excellent fit of the model to the SE and SR data, from which dispersion of optical functions as well as thickness of the OPA film were deduced. The OPA film thickness measured by atomic force microscopy (AFM) on partial coverage OPA samples was used as the initial trial film thickness in the fitting processes. The deduced OPA film thickness from SE and SR data fitting was in good agreement with that obtained by AFM.     

Plasmonic enhancement of fluorescence on silver nanoparticle films

The localized plasmon controlled fluorescence has been discussed by comparing the fluorescence enhancement of dyes on different shaped silver nanoparticle self-assembled films. A trilayer structure, composed of a silver nanoparticle monolayer, a proper thickness polyelectrolyte spacing layer and a dye-adsorbed layer, was constructed to study the plasmon enhanced fluorescence properties. The effective coupling of the plasmon band with the excitation or emission of dye resulted in different enhancement factors. Moreover, the plasmon enhanced fluorescence resonance energy transfer (FRET) of two dyes was observed. The FRET efficiency of the spherical silver nanoparticle self-assembled film had a 2.8-fold increase. The improvement of FRET efficiency via localized surface plasmons would increase the sensitivity of FRET-based bioassays.