自组装单层膜的制备与应用

本文综述了自组装单层膜制备及应用技术的最新发展,分别对有机硅烷/羟基化表面和硫醇/金两种重要的自组装单层膜体系的制备新技术以及在制膜技术和分子电子学等领域的最新应用进行了总结.     

新型溶胶-凝胶离子液体固相微萃取探头的研制

以1-羟乙基-3-甲基咪唑四氟硼酸(HEMIM[BF4])和1-羟乙基-3-甲基咪唑双三氟甲磺酰亚胺(HEMIM-[N(SO2CF3)2])离子液体为涂层材料,采用溶胶-凝胶方法制备了两种新型的离子液体-羟基硅油(OH-TSO)复合涂层固相微萃取探头,并对溶胶-凝胶反应机理和涂层性能进行了考察.由于阴离子结构不同,两种离子液体-OH-TSO复合涂层的性能也存在一定差异.首先,从表面形貌来看,HEMIM[BF4]-OH-TSO涂层表面孔洞排列更整齐,孔径更小,且大小均一.从热重分析结果来看,HEMIM[N(SO2CF3)2]-OH-TSO涂层具有更高的热稳定性,最高使用温度可以达到360℃.从萃取性能来看,HEMIM[BF4]-OH-TSO涂层对大多数酚类环境雌激素和芳胺的萃取效果明显高于HEMIM[N-(SO2CF3)2]-OH-TSO和未加离子液体的OH-TSO涂层.除此之外,它们还具有较强的抗溶剂冲洗能力,pH应用范围广,重现性好.以HEMIM[N(SO2CF3)2]-OH-TSO涂层为萃取头,采用固相微萃取-气相色谱法测定了实际水体中的芳胺.结果表明,该方法检测限低(6.3～201.3ng/L),线性范围宽(3～4个数量级),重现性好(RSD7%),准确度高(回收率87.4%～111.5%).     

巯基化合物自组装单分子层的研究进展

超薄层有机材料的制备与研究￣［１］受到人们的广泛关注，有关研究结果和进展正在不断丰富着人类对表面结构与性质关系的理解和认识。与其它制备单分子层的技术相比，自组装技术是一种较新的制备方法，在８０年代后期，迅速成为有关学科的研究焦点。采用此技术制备的超薄层体系主要有两类：一类是巯基化合物在金、银、铜、铂表面吸附形成的单层￣［２，３］，一类是在硅、玻璃、金属氧化物表面通过硅烷化反应形成的单层￣［４］。其中，硫醇类分子自组装单层（ｓｅｌｆ－ａｓｓｅｍｂｌｅｄｍｏｎｏｌａｙｅｒ，３ＡＭ）是被研究得最为广泛和深入的体系。本文主要综述十年来巯基化合物ＳＡＭ的研究进展。     

高覆盖率氟代癸基三氯硅烷自组装单分子膜的制备

通过液相沉积在云母表面制备1H, 1H, 2H, 2H-全氟癸基三氯硅烷(FDTS)自组装单分子膜(SAMs)。室温下,将1.0 mmol·L^-1的FDTS溶液静置水解15 min,再把云母浸入自组装30 min,原子力显微镜(AFM)表征发现,液相沉积过程中FDTS的团聚现象得到有效解决。该方法制备出了高覆盖率(85% ± 2%)和低均方根粗糙度(0.58 nm)的FDTS SAMs,且单分子膜的生长过程符合Langmuir一级动力学吸附模型。在液相沉积过程中,若水解和组装同时进行,过长的水解时间(大于30 min)或组装时间(大于30 min)均会导致FDTS的团聚,进而极大降低SAMs的质量。     

用于磷酸酯和甲基膦酸酯类化合物测定的固相微萃取新型涂层

以羟基硅油和二乙烯基苯为涂层材料 ,采用溶胶 凝胶技术和自由基引发交联的方法制备了一种新型的固相微萃取探头。采用顶空固相微萃取与气相色谱联用的方法模拟检测了水中磷酸酯和甲基磷酸酯类化合物。与商品化固相微萃取探头相比 ,该新型涂层可获得高的萃取效率。甲基膦酸二甲酯、磷酸三甲酯和磷酸三丁酯的最低检测限分别为 0 34,2 2 0和 0 0 1mg/L,相对标准偏差为 3 6 7%～ 6 4 4 % ,线性范围为 1～ 2个数量级 ,方法重现性好 ,回收率为 89 4 6 %～ 90 88%。     

巯基卟啉自组装膜的制备及应用研究进展

详细介绍了巯基卟啉自组装膜的几种制备方法,评述了不同制备方法的优缺点;对卟啉自组装膜在电荷转移、分子氧电催化、分子光电器件等领域的研究进展进行了评述,引用文献54篇。     

不同类型卟啉自组装膜的制备及表征

制备了不同类型的巯基卟啉自组装膜,借助多种表征技术（紫外可见光谱、电化学和X射线光电子能谱）研究了不同类型卟啉自组装膜的结构特点;研究结果表明,卟啉分子中巯基取代基数目的不同（-[SH]n-,n=1,4）,导致了卟啉环在自组装膜表面的构型不同,从而表现出不同巯基卟啉自组装膜性能的差异。 在此基础上,提出了不同巯基卟啉自组装膜的结构模型。     

Sol-Gel Method for the Preparation of Solid-Phase Microextraction Fibers

ABSTRACT

A novel sol-gel method is applied for the preparation of solid-phase microextraction (SPME) fibers. Scanning electron microscopy experiments suggested a porous structure for the poly(dimethylsiloxane) (PDMS) coating. SPME-GC analysis provided evidence that the sol-gel fibers have some advantages, such as high thermal stability, efficient extraction rates, high velocities of mass transfer, and spacious range of application.     

卟啉类自组装膜在电分析化学中的应用

评述了卟啉及其金属配合物自组装膜在电分析化学领域的应用研究进展,并简要介绍了卟啉的结构及其金属配合物的特点。对卟啉类自组装膜在电分析化学领域内的应用作了展望。     

Efficient Preparation of Novel Phenolic Surfactants for Self-Assembled Monolayers

Novel molecules have been synthesized that combine the phenolic nature of tannins and self-assembling properties of surfactants. These single-chain (C₁₂) surfactants with potential biocompatibility have been synthesized with an ω-thiol or disulfide functionality, both commonly used anchors in self-assembly onto gold surfaces, using a modular route. Protecting groups for the phenol and thiol moieties played a key role for overcoming the challenges often associated with the purification of surfactants. The tasks of unmasking the thiol moiety and simultaneously deprotecting the acetyl protecting groups of the phenols were accomplished using sodium thiomethoxide. This modular route can be extended to synthesize other surfactants with the potential ability to form robust layers with biocompatible properties.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resource(s): Full experimental and spectral details.]     

不同链长二元混合自组装薄膜的制备及其微观摩擦性能研究

采用分步组装的方法,将正己酰氯、正癸酰氯、正十四碳酰氯和硬脂酰氯按不同比例混合,接枝到3-(三甲氧基硅烷基)丙基乙烯基二胺(DA)氨基自组装膜表面,制备出一系列不同链长二元混合自组装薄膜;通过调节溶液中二元组分的相对比例,得到一系列不同厚度和不同表面润湿性的纳米有机薄膜;对薄膜进行了接触角测量、椭圆偏光测厚以及原子力形貌分析,并用摩擦力显微镜考察了其摩擦学性能.没有发现相分离现象,而且研究发现,随着长碳链分子所占比例的增大,薄膜的致密度增加,表面疏水性能增强,微观摩擦系数也随之减小.     

固相微萃取新型涂层的制备和特性(英文)

 以聚甲基苯基乙烯基硅氧烷为主要成分 ,采用溶胶 凝胶技术和自由基引发交联反应的方法首次制备了一种固相微萃取新涂层 ,并与气相联用 ,分析了芳香族化合物 ,考察了它的萃取性能。结果表明 :该涂层提供了大的比表面积 ,可获得高的萃取效率。与相应的商用固相微萃取涂层相比 ,该涂层具有更好的灵敏度和选择性 ,且热稳定性好 ,使用寿命长。     

固相微量萃取的进展

固相微量萃取是一种新的样品预处理方法，在国内还未见得以应用。本文将综述固相微量萃取的原理、装置、应用和发展。     

固相微萃取涂层制备方法研究进展

涂层是固相微萃取技术的核心,近年来出现的各种新型涂层材料和制备技术,进一步拓宽了固相微萃取技术的应用范围.该文介绍了各种新型固相微萃取介质的发展,并综述了各种新型固相微萃取涂层的制备方法,包括直接制备、溶胶-凝胶技术、化学键合与聚合、分子印迹技术、树脂固载技术、电化学沉积等.     

固相微萃取新技术

 固相微萃取是基于萃取涂层与样品之间的吸附 /溶解 解吸平衡而建立起来的集进样、萃取、浓缩功能于一体的技术。综述了固相微萃取技术的最新发展动态 ,介绍了管内 (in tube)固相微萃取、新型萃取头以及固相微萃取与其他分析技术的联用情况。     

固相微萃取法在环境监测中的应用

固相微萃取技术(SPME)作为一种样品前处理技术,具有方便、快捷、不使用有机溶剂、灵敏、价廉等优点,已被广泛地应用于环境样品的分析。综合评述了采用SPME法对3种环境基质(气态、水体、固态)中的有机物、无机离子等近百余种污染物的监测情况,并对SPME法在环境监测中的应用进行了展望。     

自组装膜技术在电分析化学中的应用

本文介绍了自组装膜的类型、结构并着重评述了有机硫化物自组装膜在电分析化学方面的应用进展。     

固相微萃取技术与环境样品前处理

固相微萃取技术是80 年代末发展起来的一项新型的无溶剂化环境样品前处理技术, 它主要与气相色谱和高效液相色谱联用, 能快速和有效地分析环境样品中的痕量有机污染物。技术从出现至今主要在萃取装置(萃取纤维涂层)、萃取方式及后序分析仪器上有较大的发展和变化, 这使得技术的应用范围不断拓宽。通过对现有文献的总结, 本文还提出了固相微萃取技术今后的发展趋势。     

Electrochemical Studies of Nanoparticle Self-Assembled Monolayers

Electrochemical studies of the self-assembled monolayers of gold nanoparticles were reported. The particle surface assemblies were constructed by using surface-active particle molecules where multiple copies of peripheral thiol groups were introduced via exchange reactions with alkanedithiols^[1,2]. Excessive dithiol and displaced thiol ligands were removed from the cluster exchange solution by liquid extraction using a hexane-methanol system. The resulting particle adlayers exhibited discrete electron-transfer features that were ascribed to the quantized capacitance charging to the particle double layers. The electrode double-layer capacitance, evaluated from impedance measurements, also showed a modulation with electrode potentials. Consistent electron-transfer rate constants were obtained from the Laviron evaluation as well as from the impedance measurements^[1].In particular, in aqueous solutions, in the presence of certain hydrophobic electrolyte ions, the discrete charging was rectified depending on the electrode^[2].     

Development of Electro Solid-Phase Microextraction and Application to Methamphetamine Analysis

A new electro solid-phase microextraction (El-SPME) technique using homemade pencil-lead fibers has been developed as an effective means of selective extraction of methamphetamine before analysis by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). The methamphetamine was extracted by use of a laboratory-made El-SPME cell with three electrodes—the pencil-lead SPME fiber, Ag/AgCl, and platinum as working, reference, and auxiliary electrodes, respectively. A negative potential was applied to the homemade pencil-lead fiber during extraction. Experimental conditions, for example type of pencil-lead fiber, conditions for modification of the fiber, extraction time, applied potential, pH, and gas chromatographic conditions were optimized. Methamphetamine was identified by GC–MS. Screening of the extracted compounds showed that the proposed El-SPME technique is much more selective than direct SPME using a commercially available polyacrylate fiber. Under the optimum conditions the calibration plot for the compound was linear in the range 50–3,200 ng mL⁻¹ and the detection limit was 34 ng mL⁻¹.