不锈钢表面Schiff碱自组装分子膜的制备及性能

以乙二胺和乙酰丙酮为原料,在盐酸催化下合成了新的Schiff 碱化合物,其收率为73.2%。 采用红外光谱和核磁共振谱对化合物的结构进行了表征。 并将其自组装在不锈钢基体表面,利用极化曲线、电化学阻抗谱和自腐蚀电位 时间曲线进行电化学分析。 结果表明,在1 mol/L HCl中,不锈钢表面自组装分子膜能快速有效的抑制异相电子的转移,促进不锈钢表面发生钝化,减少了不锈钢基体的腐蚀。 总结了Schiff碱自组装分子膜对金属防护的效用和价值。     

偶氮苯自组装单分子膜中长程电子转移机理

利用自组装技术在金电极表面构造了具有不同前端健长度偶氮苯功能化的单分子膜体系：Au／S（CH2）nNHCO-N＝N-OCH2CH3（n＝2，3，4，6）．研究结果表明，仍氮苯到金电极的表现电子转移速率随它们之间的距离长度的增加而呈指数性的下降趋势．基于Marcus电子隧穿理论，得到了此自组装膜体系的长程电子隧穿系数ρ＝（1．35±0．2）／CH2在和可逆电活性分子自组装膜体系及理论计算相比较的基础上，从偶氮苯分子自组装膜结构与电子转移过程的关系角度对这一结果进行了分析和说明．     

浸泡法和旋涂法对偶氮聚电解质静电吸附自组装膜结构及性能的影响

利用浸泡和旋涂静电吸附自组装技术制备了含有偶氮生色团的聚电解质薄膜,比较了两种方法在自组装膜生长机理、膜结构以及膜光学性能方面的差异.利用紫外光谱和椭偏仪检测自组装膜的生长情况,利用原子力显微镜对膜表面结构进行了表征,并用偏振激光在膜表面进行了写光栅实验.结果表明,采用浸泡法和旋涂法都可以制备出表面光滑均匀的含偶氮生色团的聚电解质自组装膜.但是浸泡法自组装膜的生长速度要比旋涂法快.在自组装膜厚度较小的情况下,旋涂法得到的自组装膜可以写出明显的光栅而浸泡法不可以.随着自组装膜厚度的增加,两种方法得到的自组装膜都可以写出明显的光栅.这些结果说明浸泡法自组装膜内部聚电解质分子的层间穿插比较严重,而旋涂法自组装膜内分子穿插要弱得多.     

碳纳米管/超支化重氮盐自组装膜的制备及性能研究

利用静电吸附自组装技术将酸化处理后的单壁碳纳米管(SWNTs)与超支化重氮盐(DAS)组装成多层膜.利用紫外光谱、椭偏仪、原子力显微镜、扫描电镜、拉曼光谱等对自组装膜的生长过程、膜厚增长、自组装膜表面形貌以及纳米管在膜中的存在状态等进行了检测,并利用纳米压痕仪测试了自组装膜的硬度和弹性模量.研究结果表明,SWNTs与DAS不仅发生了静电吸附,而且还发生了化学交联.同时碳纳米管均匀分散在自组装膜中.这两种因素的共同作用使得自组装膜表现出良好的纳米力学性能,硬度达到2.0GPa左右,弹性模量达到10.0GPa左右,而且可以从基底上剥离下来成为独立支撑膜.     

多巴胺在2-氨基-5-巯基-[1,3,4]三氮唑自组装膜电极上的准可逆行为研究及分析应用

利用新合成的巯基试剂2-氨基-5-巯基-[1，3，4]三氮唑在金电极表面进行了首次自组装，用电化学法和扫描电子显徽镜对自组装膜电极进行了表征。研究了多巴胺在该自组装膜电极上的电化学行为，发现该自组装膜能有效促进多巴胺在电极与溶液之间的电子传递．表现为二电子传递的准可逆行为，电极反应速率常数为0．105cm／s。该自组装膜电极用于多巴胺注射液含量的测定，结果满意。     

荧光性自组装双层膜的制备及其性能研究

借助Au-S化学键的作用,在金基底上组装DL-半胱氨酸,利用DL-半胱氨酸与1-萘胺乙酸(NAA)的静电吸引作用在金表面间接组装荧光试剂NAA,从而构建了双层自组装膜NAA/Cys/Au.该自组装膜有较强的荧光信号,能被Cu²⁺猝灭,并具有较好的可逆再生性能,可用于超痕量铜离子的界面荧光测定,对Cu²⁺的检出下限为7.87×10^-11mol/L.同时采用电化学、荧光光谱及电子能谱等方法表征自组装膜的结构,并采用电化学阻抗谱技术和循环伏安法研究自组装膜在K₃[Fe(CN)₆]/K₄[Fe(CN)₆]溶液中的电化学行为研究.结果表明,金表面组装的单层膜具有良好的“针孔”效应,组装上荧光试剂之后形成的无“针孔”缺陷的自组装双层膜对溶液与基底间的界面电子转移有强烈的阻碍作用.     

层状多核配合物自组装膜中金属离子对光致电子转移性质的影响

本文通过三种金属离子桥联的方式制备了一系列cis-RuL₂(SCN)₂ （L代表4,4’二羧基-2,2’联吡啶）自组装膜，并利用接触角,UV光谱，循环伏安法以及XPS对自组装功能膜进行了表征。通过对其光致电子转移特性的详细研究，得到了最大阳极稳定光电流为1773-1843 nA/cm²，最大量子产率为3.2%。入射光强，偏压以及电子给体对体系性能的影响也进行了研究。研究结果表明不同的金属离子桥联在自组装膜上能显著地改善电子传输特性。桥联金属离子在自组装膜中能同时起到功能和结构的两种作用。这种自组装的成膜方式提供了一种非常好的修饰此类相似体系的新途径。     

层层自组装膜的研究:从基础到生物医学领域中的应用

层层自组装是利用分子间的静电、氢键、共价键等相互作用将高分子组装成膜的技术,具有操作简单、无需特殊设备、膜组分及厚度可控等优点,在器件制备、表面改性及生物医学等诸多领域有广泛应用。我们在层层自组装膜的基础研究及应用领域均进行了一些探索,首次将氢键和共价键层层组装技术从二维体系扩展到三维体系,成功地制备了氢键和共价键键合的层层组装的空心微胶囊;提出了制备单一组分层层自组装膜的通用办法;对以聚乙烯基吡喏烷酮/聚丙烯酸膜为代表的氢键自组装膜进行了详细研究。首次以可逆共价键-苯硼酸酯键为驱动力进行层层组装,并在这些研究的基础上提出了动态层层自组装膜的概念。利用动态膜逐步解离的特性提出了新的药物释放方法,同时,利用层层自组装水凝胶膜的刺激响应性还提出了新的可快速响应的光学传感方法。     

新癌药物的电化学研究1: 一种Fe(III) Schiff碱配合物的基本电化学性质及其与DNA的相互作用

研究了一种自合成的Schiff碱配合物的电化学行为及其与氧和DNA的相互作用。发现此种Schiff碱配合物能与氧发生相互作用而具有吸氧功能, 并对氧的电还原有催化作用, 同时还发现dsDNA能与此种Schiff碱配合物发生较强的相互作用, 特别是Fe(II)Schiff碱配合物更易与dsDNA结合。     

新癌药物的电化学研究1: 一种Fe(III) Schiff碱配合物的基本电化学性质及其与DNA的相互作用

研究了一种自合成的Schiff碱配合物的电化学行为及其与氧和DNA的相互作用。发现此种Schiff碱配合物能与氧发生相互作用而具有吸氧功能, 并对氧的电还原有催化作用, 同时还发现dsDNA能与此种Schiff碱配合物发生较强的相互作用, 特别是Fe(II)Schiff碱配合物更易与dsDNA结合。     

膜电阻对自组装膜修饰电极电化学行为的影响

应用循环伏安和交流阻抗技术研究了 16烷基硫醇自组装膜修饰的金电极在Fe(CN) 63 - /Fe(CN) 64 - 溶液中的电化学行为 .无“针孔”缺陷的自组装膜对溶液与基底间的界面电子转移具有强烈的阻碍作用 ,当过电位较大时 ,In(I/ η)对 η1/2 之间具有良好的线性关系 .通过对Au/SAM /Hg模拟体系的电流———电压曲线进行测定 ,得到了自组装膜膜电阻的特征 .指出由于膜电阻的存在 ,自组装膜修饰电极在Fe(CN) 63 - /Fe(CN) 64 - 溶液中的行为实质上反映了膜自身的电阻特征     

Study of the Preparation of a Modified Lubricant Using a W/O Microemulsion Reactor and a Cyclic Voltammetry Study of Rubbing Steel S45C with Lubricants

A successful preparation of a Schiff base copper complex was carried out directly in rap oil, using a W/O microemulsion reactor. The prepared Schiff base copper complex dispersed equably and spontaneously in the oil. Owing to a modification of the rap oil, by addition of 2%wt of Cu (II) chelate of bissalicylaldehyde-ethylenediamine, the friction coefficient decreased by 80% compared to that of the original one. It was verified by energy dispersive spectroscopy (EDS) and x-ray photoelectron spectroscopy (XPS) analyses that steel/steel rubbing pairs underwent a selective transferring process with such modified lubricants. It was suggested that the mechanism for the improvement in the tribological characteristics of the modified lubricants was due to a selective transferring effect. The Cu (II) chelate of bissalicylaldehyde-ethylenediamine not only served as an additive in the rap oil, but also self-assembled on the surface of the 100Cr6 steel. The self-assembled monolayer (SAM) was examined using SEM techniques. The SAM was characterized with cyclic voltammetry (CV). It indicated that the SAM could activate the rubbing surface of 100Cr6 steel, which benefited the tribological chemical reaction.     

无长链席夫碱衍生物单分子膜和LB膜

在银离子的诱导下,两种含有苯并咪唑、没有长链取代基的席夫碱衍生物可以形成稳定的单分子膜,此单子分子膜可以用水平拉膜法转移到固体表面形成ＬＢ膜、ＬＢ膜的紫外吸收光谱和光电子能谱研究表明,Ａｇ（Ⅰ）离子被络合进行了单分子膜中。     

Supramolecular assemblies and molecular recognition of amphiphilic schiff bases with barbituric acid in organized molecular films

A bolaform Schiff base, N,N'-bis(salicylidene)-1,10-decanediamine (BSC10), has been synthesized and its interfacial hydrogen bond formation or molecular recognition with barbituric acid was investigated in comparison with that of a single chain Schiff base, 2-hydroxybenzaldehyde-octadecylamine (HBOA). It has been found that while HBOA formed a monolayer at the air/water interface, the bolaform Schiff base formed a multilayer film with ordered layer structure on water surface. When the Schiff bases were spread on the subphase containing barbituric acid, both of the Schiff bases could form hydrogen bonds with barbituric acid in situ in the spreading films. As a result, an increase of the molecular areas in the isotherms was observed. The in situ H-bonded films could be transferred onto solid substrates, and the transferred multilayer films were characterized by various methods such as UV-vis and FT-IR spectrosopies. Spectral changes were observed for the films deposited from the barbituric acid subphase, which supported the hydrogen bond formation between the Schiff bases and barbituric acid. By measuring the MS-TOF of the deposited films dissolved in CHCl3 solution, it was concluded that a 2:1 complex of HBOA with barbituric acid and a 1:2 complex of BSC10 with barbituric acid were formed. On the other hand, when the multilayer films of both Schiff bases were immersed in an aqueous solution of barbituric acid, a similar molecular recognition through the hydrogen bond occurred. A clear conformational change of the alkyl spacer in the bolaform Schiff base was observed during the complex formation with the barbituric acid.     

Immobilization of amine-modified oligonucleotides on aldehyde-terminated alkanethiol monolayers on gold

Chemistry is described for the fabrication of DNA arrays on gold surfaces. Alkanethiols modified with terminal aldehyde groups are used to prepare a self-assembled monolayer (SAM). The aldehyde groups of the monolayer may be reacted with amine-modified oligonucleotides or other amine-bearing biomolecules to form a Schiff base, which may then be reduced to a stable secondary amine by treatment with sodium cyanoborohydride. The surface modifications and reactions are characterized by polarization modulation Fourier transform infrared reflection absorption spectroscopy (PM-FTIRRAS), and the accessibility, binding specificity, and stability of the DNA-modified surfaces are demonstrated in hybridization experiments.     

Electrochemical Impedance Study of Schiff Base by Means of Self-assembled Monolayer

Schiff base and its metal complex have attracted much attention because of their wide applications in biomedicine and their specific character in photochromic field1. Up to now, reports about Schiff base mainly covered its synthesis and structure2,3. To the best of our knowledge, there is no paper dealing with Schiff base using electrochemical impedance spectroscopy technique by forming self-assembled monolayer. The complexation of Schiff base with the transition metal ions has been confir…     

Th-GSH单层膜修饰电极和多巴胺的准可逆响应

在谷胱甘肽 (GSH)自组装膜 (SAM )修饰的金电极表面共价固定硫堇 (Th)分子 ,研究其电化学性质及相关应用 ,发现该电极对多巴胺 (DO)有准可逆响应 .利用多巴胺的还原峰可在较高浓度的抗环血酸 (AA)存在条件下 (10 0倍 )对多巴胺进行检测 ,线性响应范围为 1.0～ 30 0 μmol·L- 1.     

Syntheses, Crystal Structures and Complexing Properties of 1,3-Distal Calix[4]arene Schiff Bases

Novel 1,3-distal p-tert-butylcalix[4]arene Schiff bases were efficiently synthesized in three steps. At first p-tert-butylcalix[4]arene was reacted with N-2-hydroxyethylphthalimide catalyzed by TPP/DEAD or alkylated with ω-haloalkylphthalimide in the system of K2CO3/KI/CH3COCH3 to give 1,3-distal diphthalimidoalkyl calixarenes, which were in turn hydrazinolyzed to give diaminoalkyl calixarenes. Then with the aid of the condensation of active calixarene amines with salicylaldehyde, 2-hydroxy-1-naphthaldehyde or pyridine-2-carboxaldehyde, a series of 1,3-distal calixarene Schiff bases was prepared in satisfied yields. The single crystal structures and complexing properties of these Schiff bases for transition metal ions were studied.     

Electrochemical Study of Schiff Bases by Means of Self‐Assembled Monolayers

In this paper, Schiffbases were investigated using cyclic voltammetry (CV) and impedance electrochemical spectroscopy (EIS) techniques by means of self‐assembled monolayers for the first time, where a 0.1 M KCl solution and the redox couple of Fe(CN)₆^3?/Fe(CN)₆^4?were used as the electrolyte and probing‐pin, respectively. The monolayers formed by the employed Schiff base were proved to be relatively stable, and its electrochemical response in the studied system with different pH values was also de scribed clearly with CV and EIS plots. The results show that the monolayer of Schiff bases could exist in the solution with pH value from 2 to 10. In the EIS measurement in the concentration range from 10^?5 M to 5× 10^?4 M, a nearly linear relation ship between the charge transfer resistance (R_ct) and the logarithm concentration of Cu²+was observed, suggesting that Cu²+ could be titrated with the EIS method quasi‐quantitatively. The phenomenon agreed with the former report very well. Using the self‐assembled monolayers to study Schiff bases with the electrochemical method is the major contribution of our work.     

Chemical transformations of pyridoxal and pyridoxal 5′-phosphate condensation products with amino acids

The mechanism of chemical transformations of pyridoxal and pyridoxal 5′-phosphate condensation products with amino acids is studied by kinetic measurements. The Schiff bases are shown to be fairly stable in neutral media. In acid media, the Schiff bases are hydrolyzed into the initial components. In alkaline media, cleavage of α-hydrogen from the amino acid fragment and structural rearrangement into the quinoid form followed by hydrolysis of the latter with elimination of pyridoxamine and keto acid take place. The rate constants of the chemical transformations of the Schiff bases are found to depend on the pH of the medium. It is shown for the first time that the phosphate group in the pyridoxal 5′-phosphate fragment catalyzes the α-hydrogen cleavage and strongly accelerates alkaline decomposition of the Schiff bases.