十八硫醇自组装膜对青铜-银电偶腐蚀的抑制作用

采用十八硫醇(ODT)的乙醇溶液在青铜和Ag表面制备了自组装膜(SAMs)。通过测量青铜-银的电偶电流和室内加速变色实验,研究了自组装前后的电偶腐蚀性能。采用XPS,Tafel极化曲线法和微分电容法初步研究了ODT SAMs的作用机理。结果表明:ODT分子通过S与基体形成硫醇盐,吸附在青铜和Ag表面形成自组装膜,该自组装膜在3.5%NaCl溶液和含S大气中,能够有效抑制青铜和Ag之间的电偶腐蚀,属于混和型缓蚀剂。     

十六硫醇自组装膜对Ag的防变色作用研究

针对Ag制品的变色问题,在Ag表面制备十六硫醇(HDT)自组装分子膜(SAMs),用H2S加速变色实验评价防变色效果,通过正交试验法得到最佳成膜工艺为:温度60℃,浓度0.1 mol/L,自组装时间为2 h。采用接触角测定和极化曲线、电化学阻抗、循环伏安曲线等电化学方法对膜的性能进行表征。结果表明:乙醇溶液中HDT在Ag表面形成了一层致密的自组装分子膜,具有良好的防变色效果。HDT SAMs对Ag腐蚀的阳极氧化和阴极还原均有抑制作用,膜的覆盖率为94.8%,缓蚀率达到95.9%。     

银币表面自组装膜抗变色性能及成膜机理

利用化学方法在银币表面制备了十八烷基硫醇组装膜(C18SHSAMs),并通过电化学技术研究了其在0.5mol/LNaCl+0.01mol/LNa2S溶液中的抗变色性能。结果表明:银表面形成SAMs后腐蚀电位正移30mV;阴极氧去极化和阳极银的硫化过程均受到抑制,对阴极极化过程的阻滞作用较阳极极化过程明显;银表面成膜后,容抗弧、电荷传递系数Rt增大,双电层电容Cd降低。有效提高银币的抗变色性能。银表面C18SHSAMs的形成过程符合两阶段模型。膜初始吸附阶段(I)为2级Langmuir吸附,重整结晶阶段(Ⅱ)为1级Langmuir吸附,动力学公式分别为,Ⅰ阶段:ctctt11.7061.706,Ⅱ阶段:0.5471ectt。速率常数与温度的关系为ln(k)=–5826/T+26.5,自组装过程表观活化能E=48.4kJ/mol,化学吸附为控制步骤。     

水溶液中自组装膜对银的缓蚀作用及吸附机理分析

采用不同的分散剂将十八烷基硫醇(ODT)分散在水溶液中,并以其在银表面制备了自组装膜(SAMs)。用极化曲线、交流阻抗、循环伏安等电化学方法研究了ODTSAMs对银的缓蚀作用及吸附行为。结果表明:ODT分子能够在银表面形成稳定、致密的SAMs,有效抑制了银的阴极氧去极化过程和阳极硫化过程,改变了电极表面的双电层结构,对银有良好的缓蚀作用。ODT在银表面的吸附行为符合Langmuir吸附等温式,吸附机理是典型的化学吸附。     

十八硫醇自组装膜对青铜的缓蚀作用

在乙醇体系中采用十八硫醇(ODT)在青铜表面制备自组装膜(SAMs),采用循环伏安法、极化曲线和交流阻抗谱等电化学方法研究该膜在0.5 mol/LNaCl溶液中对青铜电极的缓蚀性能。结果表明:ODT在青铜表面形成了SAMs,能够有效抑制青铜的腐蚀。随着成膜温度和ODT浓度的增高,ODT自组装膜的缓蚀效率和覆盖度提高。当ODT浓度为0.1 mol/L、成膜温度为60℃时,缓蚀效率为98.1%,覆盖度为98.7%;十八硫醇在青铜表面的吸附行为符合Langmuir吸附等温式,吸附机理是典型的化学吸附。     

十八硫醇/乙醇体系自组装膜对银的防变色作用

十八硫醇(ODT)是一种环境友好型金属处理剂。在乙醇体系中用十八硫醇在银表面制备自组装膜(SAMs)。采用加速变色、极化曲线、电化学阻抗、循环伏安等方法研究了乙醇溶液中十八硫醇自装膜对银表面的防变色作用。结果表明,在浓度为0.05mol/dm3,温度为50℃时,自组装最佳时间为1h,十八硫醇在银表面形成了一层致密的自组装膜,该膜具有良好的防变色效果。     

水溶液中自组装膜对青铜的缓蚀作用

采用不同的分散剂将十八烷基硫醇(ODT)分散在水溶液中,并以其在青铜表面制备了自组装膜(SAMs)。用极化曲线、交流阻抗、循环伏-安等电化学方法研究了ODT SAMs对青铜的缓蚀作用。结果表明:ODT分子能够在青铜表面形成稳定、致密的SAMs,有效抑制了青铜的阴极和阳极过程,改变了电极表面的双电层结构,对青铜有良好的缓蚀作用。     

Anticorrosion Action of Serf-assemble Monolayers on Bronze in Aqueous Solution

采用不同的分散剂将十八烷基硫醇(ODT)分散在水溶液中,并以其在青铜表面制备了自组装膜(SAMs).用极化曲线、交流阻抗、循环伏-安等电化学方法研究了ODT SAMs对青铜的缓蚀作用.结果表明:ODT分子能够在青铜表面形成稳定、致密的SAMs,有效抑制了青铜的阴极和阳极过程,改变了电极表面的双电层结构,对青铜有良好的缓蚀作用.     

基于激光加工和自组装技术改性处理铝镁合金的表面润湿性

为制备具有更高机械强度和更长使用寿命的超疏水金属表面,利用激光加工技术在铝镁合金表面构建出圆台凸起、圆台凹坑和正四棱台3种微结构。利用自组装技术在具有以上3种微结构的铝镁合金表面沉积自组装分子膜(SAMs),采用扫描电镜、形貌分析仪和接触角测量仪对成膜后的铝镁合金表面进行形貌和接触角的表征与测量。结果表明:沉积疏水的FDTS和OTS自组装分子膜时,接触角随微结构间距的增大而减小,随微结构高度的增大而增大,最大接触角达156°,形成超疏水铝镁合金表面;沉积亲水的APS自组装分子膜时,接触角随微结构间距的增大而增大,随微结构高度的增大而减小,最小接触角接近0°,形成超亲水铝镁合金表面;激光加工和自组装技术可以大幅度改变铝镁合金的表面润湿性。     

盐酸溶液中聚酰胺-胺树形分子-水杨醛席夫碱自组装膜对Q235碳钢的缓蚀作用及吸附机理

合成了1.0G聚酰胺-胺树状分子-水杨醛席夫碱(PAMAM(1.0G)-SA),以其在Q235碳钢表面制备自组装单分子膜(SAMs),用电化学方法研究SAMs在5%HCl介质中对Q235碳钢的缓蚀作用及其吸附行为,结果表明PAMAM(1.0G)-SA分子可以在Q235碳钢表面形成稳定的SAMs,改变了表面的双电层结构,抑制了碳钢表面的阳极氧化和阴极还原过程,碳钢电极的电荷转移电阻明显提高,双电层电容降低,电化学阻抗和极化曲线测试结果显示,碳钢表面PAMAM(1.0G)-SA的SAMs在5%HCl介质中具有良好的缓蚀作用,PAMAM(1.0G)-SA在碳钢表面的吸附行为符合Langmuir吸附等温式,属于化学吸附,利用量子化学方法对PAMAM(1.0G)-SA的SAMs形成机理进行了分析。     

Tarnish protection of silver by octadecanethiol self-assembled monolayers prepared in aqueous micellar solution

Silver will tarnish when it is exposed to the sulfur polluted atmosphere. Self-assembled monolayers are an efficient, invisible and protective film against tarnishing. SAMs prepared by the adsorption of octadecanethiol onto silver in aqueous micellar solution are explored. The silver was first degreased by acetone in an ultra-sonicate bath, followed by activation in 10% sulphuric acid solution, then, immersed in aqueous micellar solution with 0.15 mol/L octadecanethiol and 40 g/L Cetane trimethyl ammonium bromide (CTAB), Triton X-100 (TX-100), Polyoxyethylene lauryl ether (PLE) or Pluronic PE6400 during 5 min at 60 °C. The film was characterized by contact angles, FT-IR, XPS and AFM. The film was totally composed of octadecanethiol and was influenced by the surfactant in the thickness and tilt angle. The anti-tarnishing ability of the film on the silver was evaluated by electrochemical measurements in 0.5 mol/L NaCl solution containing 10 mmol/L Na₂S. The protection efficiency reached 91.9% The electro-oxidation reaction process was reduced substantially in 0.5 mol/L NaOH solution. EIS data proved that the inhibition of the monolayers was marked and the coverage of the film was more than 94.5%. The color, gloss and reflectance of silver with SAMs were almost similar to the bare silver. It was found that after 48 h accelerated tarnishing test, the protection of the thiol film remained efficient. The film controlled markedly the transfer of ion to the surface and the sulfuration rate of silver was reduced substantially.     

Microtribological and corrosion behaviors of 1H,1H,2H,2H-perfluorodecanethiol self-assembled films on copper surfaces

Fluoroorganic monolayers adsorped on copper are studied in terms of organization, structure, electrochemical behavior, corrosion and tribological properties. 1H,1H,2H,2H-perfluorodecanethiol thin films are grafted on copper via a self-assembling process. PM-IRRAS and XPS were used to investigate the organization, composition and structural properties of the SAMs. Cyclic voltammetry studies revealed a good oxidation blocking factor and polarization curves showed good anti-corrosion properties for the fluoroorganic film. However, these properties were inferior to those of n-dodecanethiol based SAMs. This was accounted for by the lower packing density and the larger number of defects of the 1H,1H,2H,2H-perfluorodecanethiol SAMs probably due to electrostatic and steric repulsion between fluorine atoms along the carbon chain and a number of CH₂ groups insufficient to permit good organization.Fluorine groups present in the monolayer of the fluoroorganic SAMs led to excellent lubricant properties for the ultrathin film. Surface wear resistance was also improved thanks to SAM grafting. 1H,1H,2H,2H-perfluorodecanethiol SAMs thus appear to be very interesting lubricants for copper as they improve surface mechanical properties by diminishing surface friction and wear.     

十二烷基硫醇在Fe表面自组装成膜及对其的腐蚀保护

应用自组装技术在Fe电极表面制备正、叔十二烷基硫醇自组装膜,用反射傅立叶红外光谱（FT-IR）、电化学阻抗谱（EIS）和Tafel极化曲线对正、叔十二烷基硫醇自组装膜进行表征,结果表明,正、叔十二烷基硫醇都能在Fe表面形成自组装膜;设计了自组装膜的等效电路,并对EIS数据进行拟合;EIS拟合结果和Tafel极化曲线均表明,正、叔十二烷基硫醇自组装膜对Fe电极在 0.5 mol/L NaCl溶液中均具有较好的缓蚀作用,并且前者的缓蚀作用强于后者。     

自组装膜技术及其在电化学分析中的应用

自组装膜技术能在分子水平上设计膜的结构,获得特殊的性能和功能,在电分析领域得到了巨大的应用,成为近年来十分活跃的研究领域.随着自组装膜应用领域的拓展,对膜的表征方法不断提出新的要求.基于此目的,综述了分子自组装膜技术的成膜方法,并从形貌、元素与结构、质量以及电化学技术等方面综述了近年来自组装膜的表征方法研究进展情况.着重介绍了自组装膜技术在电化学分析中的应用进展.     

Super-hydrophobic property of nano-sized cupric oxide films

Nano-sized cupric oxide (CuO) films with biomimetic super-hydrophobic surfaces were fabricated by isothermally oxidizing nano-sized Cu films prepared by electroless plating on smooth glass substrate following modification with octadecanethiol (CH₃-(CH₂)₁₇-SH). The microstructure characterization showed that CuO films with 54 nm thickness have a dual-scale structure consisting of the 150-200 nm agglomerates composed of the 30-50 nm granules, a similar structure to lotus-leaf. The measurement of wettability showed that CuO films modified with octadecanethiol exhibit a super-hydrophobic property with a water contact angle of ~ 154°. The mechanism leading to the super-hydrophobic property of CuO films was also analyzed based on the results of X-ray photoelectron spectroscopy (XPS).     

不同链长烷基硫醇自组装膜对银的防变色作用

将不同链长的烷基硫醇溶于乙醇,在银表面制备自组装膜。采用接触角测试、电化学试验、加速变色试验和X射线光电子能谱(XPS)等方法来表征自组装膜的性能。结果表明:十二烷基硫醇(DT)、十六烷基硫醇(HDT)和十八烷基硫醇(ODT)都可以在银表面形成疏水性的自组装膜,对基体腐蚀起到良好的保护作用;ODT自组装膜的致密性最好,而HDT自组装膜的防变色效果最好。     

溶液中含水量对铝合金表面自组装TDPA膜缓蚀行为的影晌

用含水量不同的正十四烷基膦酸（TDPA）／乙醇-水混合溶液在2024铝合金表面制备TDPA自组装膜。采用动电位扫描、电化学交流阻抗（EIS）、傅里叶红外（FTIR）、俄歇能谱（AES）以及原子力显微镜（AFM）等手段,研究白组装膜在0．1mol／L硫酸溶液中对铝合金的吸附及缓蚀性能的影响。傅里叶红外以及俄歇能谱测试结果表明：TDPA分子成功吸附于合金表面,且吸附密度随着溶液中水含量的增加而增加。电化学测试以及腐蚀形貌观察结果表明：4h的自组装能够获得最佳缓蚀效率;自组装溶液中水含量越高,得到的自组装膜缓蚀性能越好;白组装溶液中水对白组装膜性能的影响与金属表面的水化反应有关。     

Inhibition of copper corrosion by modifying cysteine self‐assembled film with alkylamine/alkylacid compounds

Complex self‐assembled monolayers (SAMs) were prepared by modifying the adsorption of cysteine with dodecylacid (DAC) and with dodecylamine (DAM) on copper surfaces. Their protective effects against copper corrosion were investigated by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) in 0.5 M HCl aqueous solution. Results show that SAMs suppress cathodic current densities and shift the corrosion potential toward more negative values. Two types of complex SAMs enhance the anticorrosion effect of cysteine SAMs. PM3 semi‐empirical quantum calculations were used to obtain the quantum chemical parameters. The complex SAMs formed from cysteine and DAM have the higher E_HOMO level and the better protection effect.     

硫醇分子自组装膜在铜表面的作用行为研究

采用动电位扫描、电化学阻抗谱、循环伏安法,研究了十二烷基硫醇分子在纯铜电极表面的自组装行为以及形成的自组装膜对铜的缓蚀作用。电化学测试结果显示:十二烷基硫醇自组装膜通过阻碍电子穿过电极/溶液界面,以及阻挡腐蚀介质与铜基底的接触,有效地抑制了铜的腐蚀;随着组装时间的延长,自组装膜更为完整,对铜的腐蚀抑制效率更高。     

Inhibition Effect of 2,4,6-Trimercapto-1,3,5-triazine Self-Assembled Monolayers on Copper Corrosion in NaCl Solution

2,4,6-Trimercapto-1,3,5-triazine (TMTA) was self-assembled on copper surface by a simple method and the resulting self-assembled monolayers (SAMs) were characterized by FTIR and contact angle. It was found that TMTA dissolved in aqueous solution could be adsorbed rapidly on the copper surface and yielded a hydrophilic surface. The inhibition effect of TMTA SAMs on copper corrosion in 0.5 M NaCl solution was investigated through potentiodynamic polarization curves and electrochemical impedance spectroscopy. Results indicated that TMTA SAMs acted as a mixed type corrosion inhibitor with predominant control of cathodic reaction. The inhibition efficiency increased with increasing assembly time but decreased to some extent with increasing concentration of chloride ions. Immersion test revealed the SAMs could keep good stability and durability in 0.5 M NaCl solution. From the experimental and theoretical study, the mechanisms of TMTA SAMs formation and corrosion protection for copper were discussed.