3-氨基-1,2,4-三氮唑自组装膜对Cu-Ni合金缓蚀作用及吸附机理研究

利用3-氨基-1,2,4-三氮唑(ATA)金属处理剂在Cu-Ni合金表面制备了自组装单分子膜(SAMs),用电化学方法研究ATA SAMs对Cu-Ni合金的缓蚀作用及其吸附行为.结果表明, ATA分子易在Cu-Ni合金表面形成稳定的ATA SAMs,抑制了Cu-Ni合金的阳极氧化过程,改变了电极表面双电层结构,使零电荷电位正移,固/液界面双电层电容明显降低,有良好的缓蚀效果,这与交流阻抗和极化曲线得到的结论一致.同时研究表明ATA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.     

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。     

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.     

铜表面吡咯烷二硫代氨基甲酸铵自组装膜的拉曼光谱和缓蚀作用

应用表面增强拉曼光谱(SERS)和电化学方法,对铜电极表面吡咯烷二硫代氨基甲酸铵(APDTC)的自组装单层结构、缓蚀性能和吸附行为进行研究。SERS光谱表明:APDTC分子通过硫原子垂直吸附在铜表面形成APDTC自组装单分子膜(APDTC SAMs)。交流阻抗和极化曲线实验表明:在3%NaCl(质量分数)溶液中APDTC SAMs对铜具有很好的缓蚀作用,最高缓蚀效率可达98%;APDTC的吸附行为符合Langmuir吸附等温式,吸附机理是介于化学吸附和物理吸附之间的一种吸附。     

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。     

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。     

光电化学方法现场监测模拟海水中铜腐蚀及缓蚀剂PTD的缓蚀行为

采用光电化学方法现场测量铜电极的开路光电压,研究铜在模拟海水3%NaCl溶液中的腐蚀行为及缓蚀剂PTD对铜的缓蚀行为.实验发现,在3%NaCl溶液中铜电极随浸泡时间的延长其开路光电压由正变负即光响应由p型光响应转变为n型光响应,这表明铜表面受到Cl-的严重侵蚀.加入缓蚀剂PTD后,当PTD的浓度小于6×10-5%时,铜电极的光响应转型时间较不加PTD时提前.当PTD的浓度大于6×10-5%时,铜电极的光响应不存在转型情况,表明PTD产生了良好的缓蚀作用.在本文条件下,PTD产生缓蚀作用的最佳浓度为1×10     

碱性介质中铜镍合金及铜电极的光电化学研究

用动电位伏安法和光电化学方法对铜镍合金(7％Ni 93％Cu)和铜电极在碱性介质中的电化学行为进行了研究。铜镍合金电极的阳极氧化膜呈p型光电响应,光电响应来自电极表面的Cu_2O膜,其厚度大于纯铜电极的Cu_2O膜。铜电极在碱性Na_2SO_4溶液中电位正向扫描时的光响应呈p型,点蚀电位以后光响应从p型转为n型。     

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。     

H2S水溶液中的腐蚀与缓蚀作用机理的研究——Ⅶ.H2S溶液中咪唑啉衍生物对碳钢腐蚀电极过程的影响

利用电化学测试技术，在H2S溶液中分别研究了14种咪唑啉衍生物浓度的变化对其缓蚀性能以及碳钢腐蚀电化学过程的影响，并对其缓蚀作用过程、缓蚀类型进行了分析探讨。结果表明，随药剂浓度升高，体系的自腐蚀电流和电极表面电容迅速减少，极化电阻增大，表明缓蚀剂分子在电极表面的吸附随药剂浓度的增加而增加，屏蔽效应增强；咪唑啉分子结构中憎水支链的长短对其缓蚀作用类型有重要影响，随支链中碳原子增加，化合物的缓蚀作用类型逐渐由阴极型向阳极型转变；按其对电极过程作用性质的不同，所研究的14种咪唑啉衍生物可分为阳极阴极缓蚀剂两组，其缓蚀作用主要是由于咪唑啉分子在电极表面的化学吸附所至。     

Electrochemical and photoelectrochemical study of the self-assembled monolayer phytic acid on cupronickel B30

The self-assembled monolayer (SAM) of phytic acid on cupronickel B30 surface of anticorrosion and inhibiting mechanism have been investigated by electrochemical and photocurrent response method. The results indicate that phytic acid is liable to interact with B30 as a result of formation of complexes on B30 surface for antirust and anticorrosion. The SAM changed the structure of the electric-double-layer and made the value of electric-double-layer capacitance decrease obviously. The B30 electrode showed p-type photoresponse, which came from Cu₂O layer on its surface. The photoresponse decreases greatly due to the SAM of phytic acid, but the corrosion resisting property is enhanced. It is in good agreement with the result by EIS and polarization curve. Adsorption of phytic acid is found to follow the Langmuir’s adsorption isotherm and the adsorption mechanism is typical of chemisorption.     

Surface characterization and corrosion behavior of 70/30 Cu-Ni alloy in pristine and sulfide-containing simulated seawater

The corrosion behavior of the 70/30 Cu-Ni alloy in stagnant, aerated pristine and sulfide-containing simulated seawater as a function of exposure time was investigated with polarization curve measurement and electrochemical impedance spectroscopy (EIS). It was demonstrated that the compact protective oxide film formed on the 70/30 Cu-Ni alloy resulted in the decrease of corrosion rate in aerated pristine seawater; while the corrosion rate of 70/30 Cu-Ni alloy in aerated sulfide-containing seawater increased dramatically due to the catalysis of the sulfide ions or sulfide scale for both the cathodic and anodic reactions. The impedance spectra and the corresponding equivalent circuits confirmed that a duplex layer of a surface film was formed on the 70/30 Cu-Ni alloy in aerated pristine seawater after a period of time and that the inner layer was responsible for the good resistance of the alloy; while only a porous and non-protective corrosion product layer formed on the 70/30 Cu-Ni alloy in aerated sulfide-containing seawater, which made small values of charge transfer resistance (R_ct) to last for a abnormally long time by interfering with the growth of the protective oxide film. The composition of the surface film on the alloy in pristine and sulfide-containing seawater for different exposure times were investigated thoroughly by XPS. It was found that the duplex corrosion product layer formed on the alloy in pristine seawater was composed of an inner Cu₂O and an outer CuO layer. The porous and non-protective corrosion product layer formed on the alloy in aerated sulfide-containing seawater was a mixture of CuCl, Cu₂S, NiS, Cu₂O and NiO with trace amounts of CuO and Ni(OH)₂ and that the most significant component was Cu₂S. In addition, SEM was used to analyze the topography of the 70/30 Cu-Ni alloy in both solutions after different exposure times.     

铝合金表面钼酸盐改进植酸转化膜的耐蚀性能

目的通过钼酸钠(SM)添加剂、SM前处理、SM后处理三种方案对铝合金表面植酸转化膜进行改进研究,以进一步提高其耐蚀性。方法通过动电位极化测试研究改进后铝合金在3.5%(质量分数)Na Cl溶液中的耐蚀性。结果随着SM添加剂浓度的增加,铝合金表面植酸转化膜的耐蚀性先增强再减弱,SM质量浓度为30 g/L时的腐蚀保护效率Pe最大,达95.5%,而不含SM时的Pe仅为86.8%。p H值太大(p H=8.0)或太小(p H=3.0)都不利于形成耐蚀性更好的膜层,p H值为6.0时的Pe达98.6%。SM后处理会严重影响植酸转化膜的耐蚀性,腐蚀电流密度Jcorr大幅增大;SM前处理可提高植酸转化膜的耐蚀性,Pe达98.2%;SM前处理与添加剂同时应用时,植酸转化膜耐蚀性提高幅度更显著,Jcorr仅为0.042μA/cm2,极化电阻Rp达222 kΩ·cm2,Pe达99.5%。结论 SM添加剂和SM前处理均可明显提高铝合金表面植酸转化膜的耐蚀性,且复合作用时的效果更显著,而SM后处理不能提高铝合金表面植酸转化膜的耐蚀性。     

温度对B30铜镍合金在海水中电化学行为的影响

采用线性极化、动电位极化、交流阻抗、循环阳极极化等测试方法,研究了温度变化对B30铜镍合金在海水中电化学行为的影响。结果表明:随着温度的升高,B30铜镍合金在海水中的腐蚀电流密度增大,生成的表面膜稳定性下降,点蚀倾向加重。     

铜镍合金在我国实海海域的局部腐蚀

研究了B10、B30铜镍合金板材和管材在我国青岛、舟山、厦门和榆林4个海水腐蚀实验站分别暴露1、2、4、8、16 a的局部腐蚀规律.结果表明:全浸区榆林海域、舟山海域和青岛海域均有一定程度的局部腐蚀,其中榆林海域因温度高和海生物附着的共同作用导致铜镍合金的局部腐蚀最严重;而厦门海域对铜镍合金的局部腐蚀有一定的减缓作用,使铜镍合金板材没有局部腐蚀发生;各海域对铜镍合金的腐蚀作用基本均以沿晶腐蚀为主,但程度不同;暴露16 a,在厦门海域B30合金的Ni、Mn和Fe含量比青岛海域和榆林海域B30合金的Ni、Mn和Fe含量高;提高B30合金的耐蚀性,是厦门海域的铜镍合金板材基本不发生局部腐蚀的内在原因.     

铜镍合金在添加不同缓蚀剂的55%LiBr溶液中的腐蚀行为

采用电化学阻抗技术研究了LiOH、Na_2MoO_4和BTA对铜镍合金在55%LiBr溶液中的腐蚀行为的影响。结果表明,单独添加LiOH和BTA都能显著减缓铜镍合金在LiBr溶液中的腐蚀,而Na_2MoO_4含量较低时可能会加速腐蚀。三种缓蚀剂复配使用,对铜镍合金在55%LiBr溶液中的腐蚀具有更好的缓蚀效果,复配后具有协同效应。试验表明,复合添加0.10 mol/L LiOH、150 mg/L Na_2MoO_4和150mg/L BTA时,对铜镍合金在55%LiBr溶液中的腐蚀具有最优的缓蚀效率。     

MB8镁合金植酸转化膜的制备及性能

通过单因素实验优化镁合金植酸转化工艺,发现在植酸体积浓度为10 mL/L,pH=2.5,温度50℃,成膜时间20 min条件下,可在MB8镁合金表面制备出均匀一致的植酸转化膜.该膜层微观形貌与铬酸盐转化膜类似,表面呈现出均匀分布的网状微裂纹,类似于"龟裂的土地",膜层主要成分为Mg,O,P,Mn和C;动电位极化曲线测试...     

具有超疏水表面的白铜在3.5%NaCl溶液中的电化学行为

通过化学刻蚀法和自组装技术,构建了白铜的超疏水表面.利用接触角测试和电化学分析技术探讨了制备工艺对疏水膜性能的影响.对不同刻蚀条件下制备的超疏水表面的电化学测试结果进行比较,结果表明:合适的表面粗糙结构是制备具有优良耐蚀性能的超疏水膜的关键.接触角测量和电化学测试结果表明:构建的白铜基超疏水表面的接触角可达152.8°,该超疏水膜能够大幅提高白铜在3.5%NaCl溶液中的耐蚀性能,缓蚀效率达到96.1%.     

Corrosion behavior of B30 Cu-Ni alloy and anti-corrosion coating in marine environment

The corrosion behavior of B30 Cu-Ni alloy in a sterile seawater and a SRB solution was investigated. The results show that the corrosion potential of specimen in the SRB solution is much lower than that in the sterile seawater. The polarization resistance of specimen in the SRB solution decreases quickly after a period immersion and becomes much lower than that in the sterile seawater. It is concluded that the SRB accelerates the corrosion process of B30 Cu-Ni alloy greatly. An anti-corrosion electroless Ni-P coating was produced and applied to the alloy. The results show that specimens coated with Ni-P plating exhibit favorable corrosion resistance property in SRB solution. Severe pitting corrosion appears on the uncoated specimens in the SRB solution when the coated specimens are still in good condition. The anti-corrosion mechanism of Ni-P plating was analyzed. It is concluded that coating the B30 Cu-Ni alloy with electroless Ni-P plating is an effective technique against the attack of SRB in marine environment.