竹叶提取液在硫酸介质中的缓蚀性能及复配研究

    应用动电位扫描法和失重法研究了竹叶提取液在硫酸介质中的缓蚀性能及其与碘化钾的复配协同效应.实验表明,当浓度为0.1 g/ml时,竹叶提取液具有良好的缓蚀性能,与碘化钾复配后,缓蚀效果更佳.电化学研究表明,竹叶缓蚀剂为混合型缓蚀剂,作用机理为几何覆盖效应.利用失重实验数据通过计算拟合,结果表明,竹叶缓蚀剂的有效缓蚀成份在碳钢表面的吸附符合El-Awady动力学模型与Flory-Huggins吸附等温方程.     

十六烷基二甲基乙基溴化铵与 NH4 SCN 缓蚀协同效应

目的研究十六烷基二甲基乙基溴化铵(CDAB)与NH4SCN在硫酸介质中对Q235钢的缓蚀协同效应,并探讨其缓蚀机理和性能,以期为工业实际生产提供理论数据。方法运用失重法研究CDAB质量浓度与缓蚀率的关系,通过失重法、动电位极化曲线法和交流阻抗法分析CDAB与NH4SCN复配后的缓蚀率和缓蚀机理。结果仅添加CDAB时,缓蚀率随着CDAB质量浓度增大而增大,但缓蚀性能并不显著,当质量浓度为10 mg/L时缓蚀率仅为85.07%;当CDAB与30 mg/L的NH4SCN复配后,缓蚀率显著提高到96.73%,能有效抑制Q235钢在0.5 mol/L硫酸介质中的腐蚀。极化试验结果显示,该复配缓蚀剂是一种以控制阳极反应为主的混合型缓蚀剂,缓蚀率随CDAB质量浓度增大而增大,与交流阻抗法、失重法试验结果相一致。复配缓蚀剂在Q235钢表面的吸附服从Langmiur吸附等温模型,吸附吉布斯自由能ΔG0=-48.33 k J/mol,为自发吸附。结论 CDAB与NH4SCN在0.5 mol/L硫酸介质中具有优异缓蚀协同效应,能有效抑制腐蚀介质对Q235钢在的腐蚀,复配缓蚀剂具有较高的缓蚀率。     

菟丝子提取物与碘化钾对冷轧钢在盐酸中的缓蚀协同效应

以寄生植物菟丝子(CCL)为原料，通过回流提取法从中提取制备出菟丝子提取物(CCLE)，通过失重法、动电位极化曲线和电化学阻抗谱(EIS)测定CCLE和碘化钾(KI)复配后对冷轧钢在1.0 mol/L HCl溶液中的缓蚀协同效应。结果表明，CCLE对冷轧钢在HCl中有较好的缓蚀作用，最大缓蚀率为84.0%；其与KI复配后，最大缓释率可进一步提升到90.8%。缓蚀协同效应系数在各复配浓度和温度下均大于1。CCLE和CCLE/KI在冷轧钢表面均符合Langmuir吸附等温式，复配后的吸附平衡常数和标准吸附Gibbs自由能(ΔG0)绝对值进一步增大。CCLE和CCLE/KI复配均属于混合抑制型缓蚀剂，但复配后对阴阳两极的抑制作用进一步增强。Nyquist图谱呈现单一半圆容抗弧，CCLE和KI复配后，电荷转移电阻明显增大。扫描电子显微镜(SEM)和原子力显微镜(AFM)表面形貌观察也表明，CCLE和KI复配后有效抑制了HCl对冷轧钢表面的腐蚀，两者存在缓蚀协同效应。     

樟树叶提取液与碘化钾的缓蚀协同效应

采用电化学方法研究了樟树叶提取液(CCIE)和碘化钾复配后(FPCCLE),对Q235钢在硫酸溶液中的缓蚀协同效应,结果表明:樟树叶提取液与碘化钾复配后,腐蚀电流密度减小,腐蚀电位负移,脱附电位Edes正移,增大了缓蚀剂的有效作用范围,提高了缓蚀剂的吸附稳定性,表现出更好的缓蚀作用,且缓蚀效率随提取液浓度的增加而增大;...     

硫酸介质中榕树叶提取液的缓蚀性能及其与 KI 的缓蚀协同效应

通过电化学方法和失重法,研究了榕树叶提取液(FLE)对碳钢在硫酸溶液中的缓蚀性能,同时研究了它与KI的缓蚀协同效应,探讨了缓蚀机理。研究结果表明:在硫酸溶液中,FLE对碳钢属混合抑制型缓蚀剂,缓蚀效率随其浓度的增加而增大;FLE与KI之间存在良好的协同效应,两者复配后,体系的腐蚀电流密度减小,电荷传递电阻增大,双电层电容减小,缓蚀效率增大,表现出更好的缓蚀作用;FLE与KI复配前后,其在碳钢表面的吸附均为自发过程,且符合Langmuir吸附等温方程。     

磺胺嘧啶和硫氰酸钠在硫酸介质中对Q235钢的缓蚀协同作用

以磺胺嘧啶(SD)和硫氰酸钠(NaSCN)在0.5 mol/L硫酸介质中对Q235钢的缓蚀作用为研究对象,采用失重法、极化曲线法、扫描电子显微镜表征等方法研究了两者复配的协同缓蚀行为及吸附模型,并通过均匀设计实验获得了复配缓蚀剂的最佳配方。结果表明:磺胺嘧啶及其复配物均为混合型缓蚀剂,都符合Langmuir等温吸附模型;复配后两种缓蚀剂之间的协同效应明显,吸附热力学和动力学参数明显改善,缓蚀率显著提高。扫描电子显微镜测试结果显示,磺胺嘧啶复配后钢表面腐蚀程度明显降低,由局部腐蚀为主转换为均匀腐蚀为主。均匀设计试验获得的复配缓蚀剂最佳配方为:磺胺嘧啶1200 mg/L、NaSCN 960 mg/L,缓蚀率高达92.65%。     

氨基酸复配酸洗缓蚀剂的研究

目的氨基酸对环境无毒无害,生产成本低,可生物降解且水溶性较高,是一种极具发展潜力的新型绿色酸洗缓蚀剂。探究在盐酸介质中,氨基酸及复配缓蚀剂对Q235钢的缓蚀作用。方法采用失重法,利用电子分析天平精确称量浸入腐蚀介质前后金属试样的质量来确定金属的腐蚀速率。研究了L-半胱氨酸及其复配缓蚀剂在1 mol/L盐酸介质中对Q235钢的缓蚀性能,借助等温吸附模型对其缓蚀机理进行了探讨。结果单独使用L-半胱氨酸缓蚀效率较低。当质量浓度为800 mg/L时,L-半胱氨酸的缓蚀效率达到最大值,为65.57%。复配合成缓蚀剂能降低经济成本,并提高缓蚀效率。通过三元复配实验得出L-半光氨酸、KI和抗坏血酸的最佳复配比,当L-半胱氨酸、KI、抗坏血酸的质量浓度分别为20、30、250 mg/L时,其缓蚀效率可达96.37%,且成本较低,是较理想的复配缓蚀剂。复配缓蚀剂在Q235钢表面的吸附符合Langmuir吸附等温模型。结论在盐酸介质中,L-半胱氨酸三元复配缓蚀剂整体用量适中,价格合理,证明复配缓蚀剂是一种能够得到良好应用的绿色缓蚀剂。     

硫酸介质中丙氨酸复合缓蚀剂的研究

目的研究丙氨酸和碘化钾共同存在于硫酸溶液中,对碳钢的协同缓蚀作用。方法采用极化曲线、交流阻抗谱、扫描电镜、X射线光电子能谱(XPS)以及El-Awady动力学模型,对丙氨酸、丙氨酸与碘化钾复配缓蚀剂对碳钢在硫酸介质中的缓蚀性能和吸附机理进行探究。结果在10%的硫酸体系中,对碳钢的缓蚀性能随着缓蚀剂浓度增大而增强。单独使用丙氨酸作为缓蚀剂,丙氨酸分子在碳钢表面呈单分子层吸附,缓蚀效率最高仅达到29%,缓蚀效果不明显。经过丙氨酸与碘化钾复配后,缓蚀效果显著提高,当丙氨酸质量浓度为300 mg/L,碘化钾质量浓度为250 mg/L时,缓蚀效率达到92%以上。XPS谱图表明,缓蚀剂主要是通过分子中的N原子与碳钢表面Fe原子形成共价键,吸附在碳钢的表面,与KI复配后,I-吸附在碳钢表面,并部分氧化,形成I_3~-。El-Awady动力学模型研究说明该复配缓蚀剂为混合型缓蚀剂,且在碳钢表面自发形成多分子层吸附膜。结论在10%的硫酸溶液中,丙氨酸分子通过物理吸附或化学吸附作用,吸附在碳钢表面,减缓腐蚀反应发生。碘化钾添加后,发挥连接缓蚀剂分子和碳钢表面的桥梁作用,从而协助丙氨酸吸附到碳钢表面,提高丙氨酸在碳钢表面的覆盖率,在提高缓蚀效率的同时,减少了丙氨酸的使用量,有效地抑制了钢材的腐蚀。     

H2SO4中丙炔醇复配缓蚀剂对碳钢的缓蚀作用

目的探究不同温度下丙炔醇、KI及其复配对Q235碳钢和N80钢片在10%(质量分数)硫酸中的缓蚀性能。方法采用静态失重法和电化学方法,60℃下测定酸液中的单剂对Q235碳钢的缓蚀性,然后对二者进行复配研究。优化配比后升高实验温度,探究高温下不同配比在酸液中对N80钢片的缓蚀性能。根据吸附等温模型和腐蚀动力学对缓蚀机理进行初步探讨。结果失重法表明,60℃时单独使用丙炔醇、KI,当质量浓度分别为120、1000 mg/L时,对Q235碳钢的缓蚀率均达到90%,两者的使用浓度较高。复配后得到两个优选配比,配比A为丙炔醇18 mg/L+KI 250 mg/L,配比B为丙炔醇15 mg/L+KI 300 mg/L,配比A、B的缓蚀率均高达98%。配比A、B的缓蚀率均随温度升高而降低,配比A在80℃酸液中对N80的缓蚀率为93%,配比B在100℃酸液中的缓蚀率为73%。结论复配后缓蚀剂的使用量均降低,且在一定高温下具有良好的缓蚀性能,丙炔醇和KI有较好的协同作用。电化学的实验结果与失重法相一致,丙炔醇和复配剂为混合型缓蚀剂。缓蚀剂在金属表面的吸附为化学吸附,符合Langmuir吸附等温模型。     

咪唑啉季铵盐缓蚀剂的合成及缓蚀行为的研究

本文以复合固体酸作催化剂,以油酸、二乙烯三胺、氯化苄为主要原料合成了咪唑啉季铵盐。用静态失重法、动电位极化曲线法、电化学阻抗法研究其在15%盐酸溶液中对A3钢的缓蚀性能。实验结果表明,缓蚀剂的缓蚀效率随着缓蚀剂浓度的增加而增加但随着温度的升高而减小。缓蚀剂浓度为10g/L时,用静态失重法测其在60℃15%盐酸溶液中的缓蚀效率为99.18%,当缓蚀剂与KI复配时,两者产生良好的协同效应:缓蚀剂与KI质量比为5:1的时候,缓蚀效率为99.7%。该缓蚀剂在A3钢表面的吸附遵循Langmuir吸附等温模型。动电位极化曲线测试表明该缓蚀剂是以抑制阴极为主的混合型缓蚀剂。     

Corrosion Inhibition of Carbon Steel by New Thiophene Azo Dye Derivatives in Acidic Solution

Inhibition of carbon steel corrosion in 2 M hydrochloric acid (HCl) solution by thiophene azo dye derivatives were studied using weight loss, electrochemical frequency modulation (EFM), and atomic absorption techniques. The experimental data suggest that the inhibition efficiency increases with increasing inhibitors concentration in presence of 10³ μM potassium iodide (KI). This is due to synergistic effect. Thus, the experimental results suggested that the presence of these anions in the solution stabilized the adsorption of inhibitors molecules on the metal surface and improved the inhibition efficiency. The results of EFM experiments are a spectrum of current response as a function of frequency. The corrosion rate and Tafel parameters can be obtained with measurement by analyzing the harmonic frequencies. The adsorption of the inhibitors on metal surface obeys the Langmuir adsorption isotherm. The surface of metal examined using Fourier transform infrared and ultraviolet spectroscopy. Quantum chemical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed.     

一种新型高温酸化缓蚀剂的制备及性能评价

目的改善缓蚀剂在高温酸液中的缓蚀性能,满足油田高温井酸化施工的要求。方法在合成一种新型吡啶季铵盐的基础上,添加炔醇、碘化钾等助剂进行复配,得到一种新型高温酸化缓蚀剂HTCI-1。使用HK-1高温高压动态腐蚀仪对其缓蚀性能进行测试,通过电化学测试、SEM、EDS等实验对其缓蚀机理进行分析。结果该酸化缓蚀剂在160℃、16 MPa、20%HCl或者土酸(12%HCl+3%HF)、质量分数3.0%的条件下,使N80试片的腐蚀速率分别为24.53 g/(m~2·h)和23.72 g/(m~2·h),达到了SY/T 5405—1996中的一级指标。结论在高温酸液中,N80钢片腐蚀速率降低,主要是由于缓蚀剂分子吸附到碳钢表面形成了一层致密的疏水性吸附膜,从而降低了侵蚀性离子与钢铁表面接触的几率,腐蚀电极反应过程受到抑制,达到了高温条件下防护金属的目的。     

Inhibition of Corrosion resistant alloys in hot hydrochloric acid solutions

Weight loss measurements were performed in 20% and 28% hydrochloric acid at 90 °C on carbon steel, 22Cr5Ni duplex stainless steel, and two superaustenitic steels – 27Cr31Ni3Mo and 19Cr25Ni4Mo –, in presence of organic substances used singly or mixed. The organic substances examined were quaternary ammonium salts (1–4-pyridyl)-pyridinium chloride hydrochloride, dodecylpy-ridiniumchloride, benzyldimethylstearylammonium chloride, and (dodecyltrimethylammonium bromide), alkynols (1-octyn-3-ol, propargyl alcohol) and trans-cinnamaldehyde. The synergistic effect of potassium iodide on the inhibitive efficiency of the organic substances was studied. The variations of corrosion rate during the test time (normally six hours) were recorded by means of polarization resistance measurements. Polarization curves were also recorded. The results showed that the corrosion rates of the four steels examined can be reduced to less than 1 mg/cm² · h using ternary inhibitor mixtures containing quaternary ammonium salts, trans-cinnamaldehyde and potassium iodide (0.2% of each component). Electrochemical tests gave useful indications on the action mechanism of the inhibitors studied.     

吐温-40 与植酸复配对碳钢的缓蚀作用

目的提高0.5 mol/L HCl中植酸对热轧碳钢(HRCS)的缓蚀性能。方法用失重法和电化学阻抗法测试植酸、吐温-40以及复配缓蚀剂的缓蚀效率,从热力学和动力学方面分析复配缓蚀剂的作用机制。结果失重法测试表明,植酸和吐温均对热轧碳钢有一定缓蚀作用。当293 K,植酸质量浓度为0.3g/L时,缓蚀效率达到69.1%,在质量浓度为0.8 g/L时缓蚀效率下降为9.6%;吐温-40的缓蚀效率随着质量浓度的增大而增大,0.8 g/L时达到73.4%。在0.5 mol/L盐酸中加入0.05 g/L吐温-40后,复配缓蚀剂的缓蚀效率随着质量浓度的增加而增大,且优于植酸和吐温-40单独使用,表现出协同效应。电化学测试得到了相同的结论,表明复配缓蚀剂在碳钢表面产生自发的Langmuir吸附,使碳钢腐蚀反应的活化能增大,是熵减少的放热过程。结论吐温-40和植酸在盐酸中对热轧碳钢的腐蚀有缓蚀协同作用。     

Protection of low carbon steel in phosphoric acid by potassium iodide

The corrosion of low carbon steel in 2.5 M phosphoric acid at temperature range of 30–60°C in presence and absence of potassium iodide as an inorganic inhibitor in the range of 0.02–0.05 M at static condition has been investigated. Weight loss and polarization techniques were employed in this investigation. The maximum value of inhibitor efficiency obtained was 99.95% at 50°C in presence of 0.05 M inhibitor concentration. The fraction of surface covered calculated from corrosion rates followed the Langmuir adsorption isotherm. Polarization experiments showed that for a given temperature, the curves were shifted towards the potential axis leading to lower the corrosion rates as the inhibitor concentration increased. Potassium iodide inhibits carbon steel corrosion in H₃PO₄ acid by affecting both anodic and cathodic partial reactions with the anodic reaction being more prevailing.     

Electrochemical assessment of inhibitive behavior of some antibacterial drugs on 316 stainless steel in acidic medium

In this work, the inhibitive effect of some antibacterial drugs against the corrosion of 316 stainless steel in 1M HCl has been studied by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The inhibiting effect explained by adsorption of the additives on steel surface. The inhibition efficiency increases with increasing the inhibitors concentrations and decreases with increasing the temperature. The data obtained fit well to Langmuir adsorption isotherm and the kinetic-thermodynamic model. The results of polarization studies indicate that the investigated antibacterial drugs are mixed type inhibitors. Increasing the inhibition efficiency of the investigated inhibitors with the addition of iodide ions indicates that iodide ions play important role in the adsorption process. The efficiencies obtained from the different electrochemical techniques were in good agreement which prove the validity of these tools in the measurements of the tested inhibitors.