竹叶提取液的制备及其缓蚀性能

植物提取液低毒,低残留,易后处理,用作缓蚀剂时环保性好.为此,用15%H_2SO_4浸泡竹叶,以其提取液配制成缓蚀剂.采用电化学测试、失重和腐蚀浸泡试验研究了竹叶不同浸泡时间、竹叶提取液浓度对Q235钢缓蚀性能的影响.结果表明:将适量竹叶用15%的硫酸浸泡306 min配制成的0.1 g/mL溶液,缓蚀效率达96%以上,是一种阳极型缓蚀剂;电化学研究表明,竹叶提取液为混合型缓蚀剂,作用机理为几何覆盖效应;失重结果表明,竹叶提取液的缓蚀效率随其浓度的增加而增大,在硫酸介质中在Q235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.     

壳聚糖季铵盐在HCl溶液中对Q235钢的缓蚀性能

目前,关于壳聚糖类缓蚀剂的报道较少,且研究温度窄,鲜见对其吸附动力学参数的分析。合成了羟丙基三甲基氯化铵壳聚糖(HACC),在30~60℃温度范围内,通过浸泡失重、电化学分析、形貌观察等方法研究了其在0.5 mol/L HCl溶液中对Q235钢的缓蚀效果。结果表明:缓蚀效率随HACC浓度升高而增加,随温度升高而降低,在30℃、HACC浓度为1.5 mmol/L时,缓蚀效率最高;HACC同时抑制了Q235钢腐蚀的阴阳极过程,通过抑制反应的活性点而起缓蚀作用;HACC在Q235钢表面的吸附符合Langmuir等温吸附模型,是自发的放热过程,属于物理和化学混合吸附,活化能是Q235钢腐蚀速率的决定性因素。     

马齿苋提取液对盐酸溶液中Q235碳钢的缓蚀作用

为了开发新型环境友好的天然缓蚀剂,采用索氏提取法提取马齿苋中的有效成分,采用失重法、动电位极化曲线和交流阻抗研究了不同浓度马齿苋提取液在1.0 mol/L盐酸溶液中对Q235碳钢的缓蚀作用及机理。结果表明:马齿苋提取液在盐酸介质中对碳钢具有良好的缓蚀效果,缓蚀效率随缓蚀剂浓度增大而升高,30℃下当提取液的浓度达到0.16 g/m L时,其缓蚀效率可达91%以上;随温度升高,马齿苋提取液对碳钢的缓蚀效率降低;马齿苋提取液是一种抑制阴阳极反应的混合型缓蚀剂,有效成分吸附在碳钢表面形成一层保护膜,吸附过程遵循Langmuir等温方程式,其在碳钢表面的吸附属于自发过程,是以化学吸附为主的物理和化学吸附共同作用的过程。     

曼尼希碱酸化缓蚀剂的合成及缓蚀性能

目前,曼尼希碱的合成多在有机溶剂中进行,其中大多有机溶剂对人体有害。以苯乙酮、甲醛、二乙胺为原料,苄基三乙基氯化铵为相转移催化剂,以水为溶剂合成曼尼希碱酸化缓蚀剂。用失重法和电化学方法考察其浓度及腐蚀液温度对20碳钢缓蚀效果的影响。结果表明:该缓蚀剂为混合型缓蚀剂,在碳钢表面的吸附为物理吸附;随温度的升高缓蚀率逐渐减小,随浓度的增加缓蚀率先增大后减小;缓蚀剂的添加量为0.7%,温度35~55℃时缓蚀率都在90%以上,能有效抑制盐酸对碳钢的腐蚀。     

薄荷叶缓蚀剂对热轧碳钢的缓蚀作用

为抑制碳钢酸洗时的腐蚀,采用加热回流萃取法从薄荷叶中提取了一种新型绿色缓蚀剂。采用失重法和极化曲线法测试了薄荷叶缓蚀剂在20~50℃时对2 mol/L HCl中热轧碳钢的缓蚀性能。结果表明:薄荷叶缓蚀剂对热轧碳钢的缓蚀效率随其浓度增加而增大,最大缓蚀率达到87.8%;当浓度小于80 mg/L时,温度升高,缓蚀效率减小;浓度大于80 mg/L时,温度升高,缓蚀效率增大;薄荷叶缓蚀剂在热轧碳钢表面的吸附作用符合Langmuir吸附模型;薄荷叶缓蚀剂对热轧碳钢的缓蚀机理为几何覆盖效应,同时抑制腐蚀反应的阴、阳极过程,属于混合型缓蚀剂。     

三嗪二硫醇化合物对铝合金的缓蚀性能

本研究采用失重法研究了三嗪二硫醇类化合物6-N,N-二丁基胺-1,3,5-三嗪-2,4-二硫醇单盐(DBN)在1mol/L盐酸溶液中对铝合金的缓蚀作用,探讨了缓蚀剂浓度、腐蚀时间和溶液温度对缓蚀效率的影响。结果表明,增大DBN浓度会提高其对铝合金的缓蚀效率,而延长腐蚀时间和升高腐蚀溶液温度都会降低其缓蚀效率。腐蚀反应动力学分析表明,添加DBN后腐蚀反应的表面活化能(Ea)增大,使腐蚀反应变得困难,从而起到缓蚀作用。同时,本研究发现DBN分子在金属表面的吸附行为符合Langmuir吸附等温线,吉布斯自由能计算(Gθads=-30.36kJ/mol)表明该吸附过程是自发的,且同时存在着物理吸附和化学吸附。扫描电子显微镜测定结果表明DBN能够有效地抑制铝合金在酸性介质中的腐蚀。     

氟康唑在3%HCl溶液中对45钢的缓蚀性能

有机缓蚀剂用于钢铁的腐蚀防护具有用量少、缓蚀性能佳的特点,已得到广泛研究,其中,三氮唑类抗真菌药品氟康唑对碳钢的缓蚀研究报道较少。通过失重试验和电化学测试研究了氟康唑在3%HCl中对45钢的缓蚀性能。结果表明,氟康唑浓度较低时,缓蚀效率随浓度的增大而升高,浓度为650 mg/L左右时,缓蚀效率达到85.8%以上;但用量过高,缓蚀效率反而随浓度的增加而降低。动电位极化曲线测试证实氟康唑是一种抑制阳极过程为主的混合型缓蚀剂。氟康唑分子在碳钢表面的吸附行为服从Langmuir吸附等温式的自发过程,是物理吸附与化学吸附共同作用的结果。     

2种四唑衍生物缓蚀剂在碱性介质中对铜的缓蚀性能和吸附行为

有机缓蚀剂能在金属表面发生吸附而降低金属的腐蚀速率,但目前对其在金属表面的吸附机理仍不十分清楚.合成了胍基四唑(GT)和1-(对甲基)苯基-5-巯基-1,2,3,4-四氮唑(MMT)2种缓蚀剂,用失重法和电化学法研究了2种缓蚀剂在5%NaHCO_3碱性介质中对铜的缓蚀性能和吸附行为.结果表明:MMT和GT属于阳极型缓蚀剂,对铜均有很好的缓蚀性能,且MMT的缓蚀效率大于GT;MMT和GT均在浓度为50 mg/L时缓蚀效率最大(90%以上);30～60℃时2种缓蚀剂的缓蚀性能随温度的升高而降低;2种缓蚀荆在铜表面的吸附都服从Langmuir吸附等温式,属于物理吸附.     

桂花果提取液在1 mol/L盐酸介质中对A3钢的缓蚀性能

为了开发A3钢盐酸清洗中的天然绿色缓蚀剂,通过索式提取法从桂花果中提取植物缓蚀剂,采用失重法、极化曲线和电化学阻抗谱(EIS)研究了不同浓度桂花果提取液在1 mol/L盐酸介质中对A3钢的缓蚀性能,并探讨了缓蚀机理。结果表明:以95%的乙醇为溶剂索式提取的桂花果提取液在1 mol/L盐酸介质中对A3钢具有良好的缓蚀性能,缓蚀效率随其浓度的增加而增大,当其浓度达到25 g/L时,缓蚀效率可达93%以上;桂花果提取液为混合型缓蚀剂,缓蚀机理为"几何覆盖效应",其有效缓蚀成分在A3钢表面的吸附符合Langmuir等温式,吸附平衡常数为1.89 L/g。     

过期药头孢氨芐在含氯离子的20%醋酸中对冷轧钢的缓蚀行为

过期药对金属缓蚀作用的研究为其再回收利用提供了一个较好的方向,具有一定的环境保护意义。为了探究抗生素类药物对酸性介质中金属腐蚀的影响,利用失重法、电化学法研究了头孢氨芐在含氯离子的20%醋酸溶液中对冷轧钢的缓蚀作用。结果表明:头孢氨芐在含氯离子的20%醋酸溶液中对冷轧钢的腐蚀有良好的抑制作用,且缓蚀率随着缓蚀剂浓度的增加而增大,当头孢氨苄浓度为0.020 mol/L时,缓蚀率达到了85.4%;该缓蚀剂的吸附行为是一种物理吸附,吸附过程是一个自发的单分子吸附过程。     

Green approach to corrosion inhibition of mild steel in two acidic solutions by the extract of Punica granatum peel and main constituents

The effect of the extract of Punica granatum (PG) and their main constituents involve ellagic acid (EA) and tannic acid (TA), as mild steel corrosion inhibitor in 2 M HCl and 1 M H₂SO₄ solutions was investigated by weight loss measurements. The results obtained from the weight loss measurements show that the inhibition efficiency of TA even in high concentration is very low. Thus, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) investigations were used for different concentrations of PG and EA and best concentration of TA. Potentiodynamic polarization curves indicated that PG and EA behave as mixed-type inhibitors. EIS measurements show an increase of the transfer resistance with increasing inhibitor concentration. The temperature effect on the corrosion behavior of steel without and with the PG extract was studied. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm.     

鲜白酒糟提取液对Q235钢硫酸酸洗的缓蚀性能

为了综合利用白酒糟和开发新型绿色酸洗缓蚀剂,制取了鲜白酒糟提取液,采用失重法和电化学法研究了其作为硫酸酸洗缓蚀剂的缓蚀性能。结果表明:15 g酒糟在300 mL 5%硫酸溶液中30℃静置浸泡6 h,得到的提取液在5%硫酸介质中对Q235钢的缓蚀率最高;酒糟提取液在Q235钢表面的吸附符合El-Awady动力学模型和Flory-Huggins吸附等温方程,属于几何覆盖效应的单分子层吸附,提取液为混合型缓蚀剂;放置时间延长时,提取液的缓蚀率降低。     

Acid Cleaning of Steel Using Arghel Echo Friendly Corrosion Inhibitor

Acid cleaning of mild steel dissolution by 1M sulfuric acid/10 % methanol (test solution) in presence of Arghel herb extract as green inhibitor were monitored by potentiodynamic and electrochemical impedance techniques in the temperature range 30–60^oC. At all temperature, the corrosion rate decreased with increasing inhibitor concentration. Potentiodynamic polarization measurements indicated that the inhibitor has strong effect on the corrosion behavior of the steel and behave as mixed type inhibitor. Impedance results indicate that the charge transfer controls the dissolution mechanism of steel across the phase boundary in the absence and the presence of the inhibitor. The inhibition efficiency obtained from various employed methods is in good agreement. Thermodynamic and activation parameters obtained from this study indicated that the presence of the Arghel increases the activation energy, and the adsorption process of the inhibitor on the metal surface is spontaneous.     

Effect of some ethoxylated fatty acids on the corrosion behaviour of mild steel in sulphuric acid solution

The inhibition of the corrosion of mild steel in 1.0 M sulphuric acid solution by some ethoxylated fatty acids OL[EO]₂₀, OL[EO]₄₀ and OL[EO]₈₀ has been studied in relation to the concentration of the inhibitors as well as the temperature using chemical (weight loss) and electrochemical (potentiodynamic polarization) techniques. The inhibition efficiency increases with increasing the concentration and the chain length of the inhibitor but decreases with temperature. The inhibition was assumed to occur via adsorption of the fatty acid molecules on the metal surface. The thermodynamic functions of dissolution and adsorption processes were calculated.     

模拟2倍浓缩海水中聚环氧琥珀酸和Na2MoO4对304不锈钢的缓蚀作用

为开发适用于循环冷却海水／不锈钢体系的绿色缓蚀剂,采用电化学阻抗谱、极化曲线及表面腐蚀形貌分析,研究了聚环氧琥珀酸（PESA）、Na2MoO4在模拟2倍浓缩海水中对304不锈钢的缓蚀作用。结果表明：在模拟2倍浓缩海水中,PESA与Na2MoO4均能在304不锈钢表面形成保护膜,产生缓蚀作用;PESA为阳极吸附型缓蚀剂,...     

葡萄糖与甘氨酸反应产物对碳钢的缓蚀效果

为了解葡萄糖与甘氨酸反应产物对碳钢的缓蚀效果,采用失重法、电化学法并结合扫描电镜观察,研究了葡萄糖与甘氨酸反应产物(PGG)对碳钢在1 mol/L HCl溶液中的腐蚀抑制作用。结果发现:PGG对碳钢表现出很好的缓蚀效果,缓蚀效率随添加浓度的增加而增加,在最大浓度250 mg/L时,表现出最好的缓蚀效果,缓蚀效率为94.7%,且缓蚀效率随温度升高而降低。PGG同时抑制了碳钢腐蚀的阴极还原反应和阳极氧化反应过程,为混合型缓蚀剂,是通过多组分的物理和化学联合吸附,在碳钢表面上形成保护性覆盖层,将碳钢与酸溶液隔离,从而起到缓蚀作用,其吸附行为遵循Langmuir吸附等温模型。葡萄糖与甘氨酸反应产物(PGG)是碳钢在1 mol/L HCl溶液中的优良缓蚀剂。     

氨基磺酸中肉桂醛缩甲胺席夫碱对Q235钢的缓蚀吸附行为

为进一步研究肉桂醛缩甲胺席夫碱在氨基磺酸介质中对碳钢的腐蚀机理,利用极化曲线、原子力显微镜、X射线光电子能谱仪和量子化学计算,研究了5%氨基磺酸介质中肉桂醛缩甲胺席夫碱在Q235钢表面的缓蚀吸附行为。结果表明:在70℃、5%氨基磺酸介质中,肉桂醛缩甲胺在Q235钢表面的吸附行为符合Langmuir吸附等温式,是一种混合型缓蚀剂,且该缓蚀剂在Q235钢表面的吸附存在不均匀性;Q235钢在氨基磺酸溶液中的腐蚀产物主要为Fe SO4、Fe S,缓蚀剂的吸附抑制了Fe S的生成。     

Effect of NaBr on the corrosion of cold rolled steel in 1.0 M phosphoric acid

The inhibition of NaBr on the corrosion of cold rolled steel in 1.0 M phosphoric acid was studied by using weight loss method and polarization method. It was found that the adsorption of bromide ion can prevent steel from corrosion and the adsorption follows the Langmuir adsorption isotherm. Polarization studies showed that NaBr is a mixed-type inhibitor for steel corrosion in 1.0 M phosphoric acid. Thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy were obtained from the experimental data of temperature studies for the inhibition process at four temperatures ranging from 30 to 45°C. The kinetic data such as apparent activation energies and pre-exponential factors at different concentrations of the inhibitor were calculated, and the effects of the apparent activation energy and pre-exponential factor on the corrosion rate of cold rolled steel were discussed. The inhibitive action was satisfactorily explained by using thermodynamic and kinetic models. The results obtained from polarization experiment were in good agreement with those obtained from weight loss measurement.     

双缩合希夫碱耐温酸化缓蚀剂的合成及性能研究

为了解决原油开采中酸液腐蚀的问题,采用溶剂法合成出2种双缩合希夫碱缓蚀剂XFJ-1、XFJ-2.针对90℃、15％(质量分数)HCl的环境,通过静态失重法、极化曲线法等方法评价了其缓蚀性能,并采用模拟手段从分子层面解释了二者的缓蚀机理.结果表明:2种缓蚀剂在质量分数分别为1.0％时缓蚀效率分别可以达到82.90％和99...