糖基季铵盐双子表面活性剂的缓蚀性能

由葡萄糖和十四烷基二甲基叔胺合成的糖基季铵盐双子表面活性剂(C14-GDQ)作为缓蚀剂,用静态失重法研究了该表面活性剂在1 mol/L盐酸溶液中对Q235钢的缓蚀作用。结果表明,在1 mol/L盐酸溶液中C14-GDQ对Q235钢具有良好的缓蚀作用,缓蚀率随缓蚀剂浓度的增加而增大,当缓蚀剂质量浓度达到0.1mmol/L时缓蚀率趋于稳定。通过吸附理论、动力学和热力学公式得到相应的参数,并讨论了缓蚀作用机理。     

几种表面活性剂对饱和的H_2S/CO_2介质中Cr13钢的吸附与缓蚀性能

采用浸泡失重法、电化学方法,研究了在50℃饱和的H2S/CO_2介质中Gemini表面活性剂和咪唑啉表面活性剂在Cr13钢上的吸附行为与缓蚀性能。结果表明,所研究的几种表面活性剂均在Cr13钢表面上形成致密的单分子吸附层,且吸附服从Langmuir方程式,表现出优异的缓蚀性能,明显抑制了Cr13钢在50℃饱和H_2S/CO_2介质中的腐蚀;其缓蚀能力排序为:12-6-12型Gemini表面活性剂>16-2-16型Gemini表面活性剂>咪唑啉。此外,当Gemini表面活性剂的浓度达到50 mg/L时,其缓蚀率可达到85%左右。     

盐酸介质中表面活性剂对碳钢缓蚀作用的研究

研究了几种表面活性剂在盐酸介质中的缓蚀作用以及与六次甲基胺复配时的协同缓蚀作用，探讨了碳钢在盐酸，六次甲基四胺和十二烷基硫酸钠混合溶液中的钝化机理。     

硫酸介质中Gemini表面活性剂对碳钢的吸附缓蚀性能

通过失重法和极化曲线法研究了阳离子季铵盐型Gemini表面活性剂Π-14-3及其添加卤离子的复配体系对A3钢在硫酸溶液中的缓蚀性能及其机理.结果表明,表面活性剂分子Π-14-3对A3钢在0.5 mol/L的硫酸中具有很好的缓蚀性能;在缓蚀剂浓度很低时,通过加入一定量的卤离子,可以得到较高的缓蚀性能,从而降低其应用成本;在硫酸介质中,Gemini表面活性剂在金属表面的吸附符合Langmuir吸附机理.     

盐酸介质中双子表面活性剂对N80钢的吸附缓蚀性能

采用静态失重法、电化学方法和扫描电镜等方法,研究了一种双子表面活性剂(DBA2-12)对N80钢在盐酸介质中的吸附缓蚀性能。结果表明,DBA2-12对N80钢在1 mol/L的盐酸溶液中具有较好的缓蚀性能。随着缓蚀剂浓度的增加,缓蚀率增大;随着实验温度升高,缓蚀率减小。该缓蚀剂在N80钢表面的吸附遵循Langmuir吸附等温式,是一种混合抑制型缓蚀剂。     

Gemini双季铵盐捕收剂BDDA和EDDA对高岭石、叶腊石、伊利石浮选行为的比较及机理

采用了新型Gemini双季铵盐捕收剂丁烷-1,4-双十二烷基二甲基溴化铵（BDDA）和乙烷-1,2-双十二烷基二甲基溴化铵（EDDA）对比研究了其对高岭石、叶腊石、伊利石的浮选行为及作用机理。单矿物试验结果表明,在广泛的pH范围内,新型Gemini双季铵盐捕收剂BDDA和EDDA对三种铝硅酸盐矿物具有优异的捕收性能,且BDDA的捕收能力强于EDDA。红外光谱和动电位研究表明,Gemini双季铵盐捕收剂对三种铝硅酸盐矿物的作用机理为静电吸附和氢键作用。采用DFT密度泛函理论,在B3LYP／6—31G（d）水平上对捕收剂阳离子BDDA2＋和EDDA2＋进行量化计算,结果表明BDDA的捕收能力强于EDDA。这与单矿物浮选结果、动电位测定结果一致。     

季铵盐双子表面活性剂的缓蚀性能研究

采用自制的季铵盐双子表面活性剂1,6-二(癸烷基吗啉)己烷(HDMB)作为缓蚀剂,用失重及极化曲线研究了该表面活性剂在1 mol/L盐酸溶液中对Q235钢的缓蚀效果.失重结果表明:在1 mol/L盐酸溶液中HDMB对Q235钢具有良好的缓蚀作用,缓蚀率随缓蚀剂浓度的增加而增大,当浓度达到0.1 mmol/L时,缓蚀率趋于稳定.通过吸附理论、动力学和热力学公式得到相应的参数,并讨论了缓蚀作用机理;极化曲线法表明:HDMB为混合抑制型缓蚀剂.     

酸性溶液中双子表面活性剂对金属锌的缓蚀性能

采用失重法和电化学方法研究了双子表面活性剂在1mol/L HCl溶液中对锌的缓蚀性能,通过对吸附热力学和腐蚀动力学参数的计算,探讨了缓蚀机理。结果表明:[C12-4-C12im]Br2在盐酸溶液中对锌具有较好的缓蚀作用,是一种混合型缓蚀剂。缓蚀率随着缓蚀剂加入量的增加而增大,随着温度的升高而减小。该缓蚀剂在锌表面的吸附符合Langmuir吸附等温式,吸附过程是自发的,同时兼有物理和化学吸附。     

NaOH溶液中表面活性剂对工业纯铝的缓蚀作用

采用失重法研究了阴离子表面活性剂油酸钠(SO)和阳离子表面活性剂溴化十四烷基吡啶(TDPB)在0.1mol/LNaOH溶液(20~50℃)中对工业纯铝的缓蚀作用。结果表明:SO在20~50℃时对铝基本无缓蚀作用。TDPB对铝在20℃和30℃时缓蚀效果较差;但在40℃和50℃时TDPB对铝具有良好的缓蚀作用,50℃时1.0×10-3mol/LTDPB对铝的最大缓蚀率为81.2%。TDPB在铝表面的吸附符合校正的Langmuir吸附模型,根据热力学公式求出了吸附热力参数(吸附自由能ΔG0,吸附焓ΔH0,吸附熵ΔS0),并用吸附观点讨论了缓蚀作用机理。     

十二胺在碳钢表面的吸附行为

利用原子力显微镜（AFM）、动电位扫描及润湿角测量等手段研究了盐酸溶液中十二胺在碳钢表面的吸附行为及其对碳钢腐蚀行为的影响。结果表明：十二胺在碳钢表面形成了单分子吸附层。其对碳钢的缓蚀机理主要为“几何覆盖效应”，一个十二胺分子平均可以取代2．32个水分子；碳钢表面的润湿性随缓蚀剂浓度的增大而减弱。AFM电流图像显示，碳钢表面有十二胺吸附的部位导电性能明显减弱；AFM力—距离曲线表明，碳钢表面有缓蚀剂吸附的部位呈现出明显的黏附力。     

The adsorption and corrosion inhibition of some cationic gemini surfactants on carbon steel surface in hydrochloric acid

The adsorption and corrosion inhibition of the gemini surfactants 1,2-ethane bis(dimethyl alkyl (C_nH_2n+1) ammonium bromide) (designated as n−2−n, n=10, 12 and 16) on the steel surface in 1 M hydrochloride acid were studied using the weight loss method. It was found that the adsorption of the gemini surfactants on the steel surface is the main reason to cause the steel corrosion inhibition in hydrochloride acid, and the inhibition efficiency increases with the increase of surfactant concentration and reaches the maximum value near the CMC. A possible adsorption model of gemini surfactant onto the metal surface was also discussed.     

Synergistic effect between cationic gemini surfactant and chloride ion for the corrosion inhibition of steel in sulphuric acid

Corrosion inhibition of cold rolled steel in 0.5 mol L⁻¹ sulphuric acid by a quaternary ammonium gemini surfactant, l,3-propane-bis(dimethyl dodecylammonium bromide) (designated as 12-3-12), in the absence and presence of chloride ions was investigated at different temperatures. The results revealed significant synergistic effect between gemini 12-3-12 and chloride ions for the corrosion protection of cold rolled steel in sulphuric acid, and that the novel composite inhibitor system containing cationic gemini surfactant and chloride ions was efficient and low-cost for steel corrosion inhibition in sulphuric acid medium, even when concentration of 12-3-12 was as low as 1 × 10⁻⁶ mol L⁻¹. By fitting the obtained experimental data with Langmuir adsorption model and Arrhenius equation, some thermodynamic and kinetic parameters such as adsorption free energy, the apparent activation energy, and the pre-exponential factor were estimated. The adsorption mechanism of the gemini surfactant onto steel surface in acid medium in the absence and presence of chloride ions was also discussed, respectively.     

含二长链烷基溴化铵的合成及其缓蚀性能和吸附模型的研究

以二甲基十六烷基胺等为原料,合成了十六烷基辛基二甲基溴化铵和十六烷基癸基二甲基溴化铵,用线性极化法研究了它们对５％ＨＣｌ中碳钢的缓蚀作用,并确定了它们的吸附模型。结果表明：它们对酸液中碳钢的腐蚀具有明显的抑制作用,在碳钢表面的吸附遵循Ｌａｎｇｍｕｉｒ等温式。     

A novel Schiff base-based cationic gemini surfactants: Synthesis and effect on corrosion inhibition of carbon steel in hydrochloric acid solution

The corrosion inhibition characteristics of the synthesized cationic gemini surfactants, namely bis(p-(N,N,N-decyldimethylammonium bromide)benzylidene thiourea (10-S-10), bis(p-(N,N,N-dodecyldimethylammonium bromide)benzylidene thiourea (12-S-12) and bis(p-(N,N,N-tetradecyldimethylammonium bromide)benzylidene thiourea (14-S-14) on the carbon steel corrosion in 1 M hydrochloric acid have been investigated at 25 °C by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The inhibition efficiencies obtained from all methods employed are in good agreement with each other. The obtained results show that compound 14-S-14 is the best inhibitor with an efficiency of 97.75% at 5 × 10⁻³ M additive concentration. Generally, the inhibition efficiency increased with increase of the inhibitor concentration. Changes in impedance parameters (charge transfer resistance, R_ct, and double-layer capacitance, C_dl) were indicative of adsorption of 14-S-14 on the metal surface, leading to the formation of a protective film. The potentiodynamic polarization measurements indicated that the inhibitors are of mixed type. The adsorption of the inhibitors on the carbon steel surface in the acid solution was found to obey Langmuir’s adsorption isotherm. The free energy of adsorption processes were calculated and discussed. The surface parameters of each synthesized surfactant were calculated from its surface tension including the critical micelle concentration (CMC), maximum surface excess (Γ_max) and the minimum surface area (A_min). The free energies of micellization (ΔG^o_mic) were calculated. The surface morphology of carbon steel sample was investigated by scanning electron microscopy (SEM).     

含羟基双子表面活性剂在CO2饱和盐水溶液中对Q235钢的缓蚀性能

合成了4种不同链长的n-3OH-n(n=12,14,16,18)型双子表面活性剂,并用静态失重法、动电位极化和电化学阻抗谱技术研究了其在CO₂饱和的盐水溶液中对Q235钢的缓蚀作用。结果表明,在60℃时4种表面活性剂对Q235钢均表现出一定的缓蚀效果。其中,12-3OH-12和14-3OH-14缓蚀效果更为显著。动电位极化曲线表明n-3OH-n(n=12,14,16,18)型双子表面活性剂是一种阴极阳极共同抑制但以阳极抑制为主的混合型缓蚀剂。电化学阻抗测试与极化曲线和失重法得到的结论基本一致。     

Novel cationic gemini surfactants as corrosion inhibitors for carbon steel pipelines

In the present investigation novel cationic gemini surfactants namely: bis(p-(N,N,N-octyldimethylammonium bromide)benzylidene)benzene-1,4-diamine (I), bis(p-(N,N,N-decyldimethylammonium bromide)benzylidene)benzene-1,4-diamine (II), and bis(p-(N,N,N-dodecyldimethylammonium bromide)benzylidene)benzene-1,4-diamine (III) were synthesized, characterized, and tested as corrosion inhibitors for carbon steel in 1 M HCl solution. The corrosion inhibition efficiency was measured by using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, and weight loss methods. The obtained results showed that, the synthesized inhibitors are excellent inhibitors for carbon steel in 1 M HCl solution. The inhibition efficiency decreased in the temperature range 30-40 °C and then increased in the temperature range 40-60 °C. The prepared inhibitors act as mixed inhibitors. Thermodynamic and activation parameters were discussed. Adsorption of the synthesized inhibitors was found to follow the Langmuir’s adsorption isotherm. Mixed physical and chemical adsorption mechanism is proposed. The morphology of carbon steel samples was investigated by scanning electron microscopy (SEM).     

Inhibition of Mild Steel Corrosion Using l-Histidine and Synergistic Surfactants Additives

The corrosion inhibition behavior of nitrogen-containing amino acid l-Histidine (LHS) on mild steel in 0.1 M H₂SO₄ solution in the temperature range of 30-60 °C was studied by weight loss measurements, and potentiodynamic polarization measurements. The effect of the addition of very small concentration of surfactants, sodium dodecyl sulfate (SDS), and cetyltrimethyl ammonium bromide (CTAB), respectively on the corrosion inhibition behavior of LHS was also studied. The surface morphology of the corroded steel samples was evaluated by scanning electron microscopy (SEM) and atomic force microscopy (AFM). LHS significantly reduces the corrosion rates of mild steel, with the maximum inhibition efficiency (IE) being 71.09% at 30 °C in the presence of 500 ppm of LHS. The IE of LHS is synergistically increased in the presence of SDS and CTAB. The SEM and AFM photographs show a clearly different surface morphology in the presence of additives. LHS alone and in combination with surfactants obeys Langmuir adsorption isotherm from the fit of the experimental data of all concentration and temperature studied. The calculated thermodynamic parameters for adsorption reveal strong interaction between the inhibitors and the mild steel surface, and suggest physical adsorption. The results obtained by potentiodynamic polarization measurements are consistent with the results of the weight loss measurement. LHS acts more anodic than cathodic inhibitor.     

Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV (∼96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules.