席夫碱缓蚀剂对碳钢材料的缓蚀性能

采用失重法和电化学方法研究了2种席夫碱类缓蚀剂N,N′-二水杨醛基-1,2-乙二亚胺(SB-Ⅰ)和水杨醛基吡啶-2-亚胺(SB-Ⅱ)在1mol/L盐酸溶液中对A3碳钢的缓蚀性能。失重实验表明,SB-Ⅰ和SB-Ⅱ在1mol/L盐酸溶液中的浓度为20mmol/L时,缓蚀效率分别达85%和92%。经三电极体系极化曲线和交流阻抗谱测定实验表明,缓蚀性能是由于碳钢材料表面为缓蚀剂分子吸附所致,二者均属阴极型缓蚀剂。     

两种席夫碱缓蚀剂对碳钢材料的缓蚀性能探究

采用了电化学方法研究了2种席夫碱缓蚀剂水杨醛基邻苯甲酸亚胺(SB-I)和N,N’-二水杨醛基-1,2-邻苯二亚胺(SB-II)在1 mol/L盐酸溶液中对20#碳钢的缓蚀性能。通过极化曲线和交流阻抗谱研究该席夫碱对碳钢的缓蚀效果表明:席夫碱对碳钢材料具有良好的缓蚀作用,其最大缓蚀率可达到83%。研究了席夫碱在碳钢表面的吸附模式,结果表明,席夫碱在碳钢表面上的吸附吉布斯自由能在-30 kJ/mol之间,表现为混合型缓蚀剂,即通过化学吸附和物理吸附之间的一种混合吸附在碳钢工作电极的表面,通过抑制、阻止延缓金属的电化学过程而起到缓蚀的作用。另外,实验还发现,SB-I比SB-II具有更好的缓蚀性能,该实验结果与理论计算结果相符合。     

绿色聚天冬氨酸复配缓蚀剂对A3碳钢的缓蚀抑雾作用

采用失重法和极化曲线法研究了聚天冬氨酸(PASP)和十二烷基酚聚氧乙烯醚(OP-10)复配对A3碳钢在6mol·L-1HCl腐蚀介质中的协同吸附行为及缓蚀抑雾作用.结果表明:复配缓蚀剂可有效抑制A3碳钢在HC1介质中的腐蚀,当PASP浓度为20g·L-1,缓蚀率可达94%,抑雾率83%;随着温度的升高,复配缓蚀剂的缓蚀性能下降.复合缓蚀剂在钢表面的吸附符合校正的Langmuir模型,吸附过程为放热、熵减的自发过程;复配体系属于阳极型缓蚀剂.     

红茶提取液在盐酸中对碳钢的缓蚀作用

采用动电位极化曲线和交流阻抗（EIS）研究了红茶提取液（BLE）在盐酸介质中对碳钢的缓蚀性能和缓蚀机理。 研究结果表明,采用索氏提取法从红茶茶叶中提取的缓蚀剂,对碳钢在1.0 mol/L盐酸溶液中具有良好的缓蚀性能,随着提取物浓度的增加,缓蚀效率增大。 红茶提取液中的有效缓蚀成分为抑制阴阳极反应的混合型缓蚀剂,在碳钢表面的吸附符合Langmuir等温式,属于单分子层吸附。     

具有表面活性的杂环缓蚀剂的合成及性能评价

以2-氨基苯并咪唑、氰尿酰氯、正己胺以及N,N-二甲基-1,3-丙二胺为原料,合成一种具有表面活性的杂环类缓蚀剂。通过测定含不同浓度缓蚀剂的盐酸溶液的表面张力来研究其表面性能。采用失重法和动电位极化及电化学阻抗谱方法考察了其与2-氨基苯并咪唑在盐酸介质中对碳钢的缓蚀行为,并通过扫描电镜观察了腐蚀碳钢试片的外貌形态。结果表明,表面活性以及多活性吸附中心的引入提高了缓蚀剂在碳钢表面的吸附能力,合成的缓蚀剂的缓蚀性能比2-氨基苯并咪唑有显著提高。在实验范围内,缓蚀剂的缓蚀效率随浓度增大而提高,电化学测试表明其为一种混合型缓蚀剂。     

盐酸介质中水杨醛缩氨基硫脲对碳钢的缓蚀作用

合成了新型席夫碱缓蚀剂:水杨醛缩氨基硫脲(ST),并考察了其在1 mol/L盐酸溶液中对碳钢的缓蚀性能。通过静态失重、动电位极化曲线、交流阻抗等技术手段研究缓蚀剂浓度对腐蚀速率及缓蚀效率的影响,阐明缓蚀作用机理。结果表明,ST在盐酸介质中对碳钢具有良好的缓蚀性能。随着缓蚀剂浓度的增加,缓蚀效率逐渐增大。ST的加入显著降低了自腐蚀电流密度,为抑制阴极反应为主的缓蚀剂。ST在碳钢表面的吸附符合Langmuir吸附模型,为物理吸附与化学吸附共同作用。     

蛋氨酸衍生物的合成及其缓蚀性能研究

本文合成了一种新型蛋氨酸衍生物酸洗缓蚀剂,运用红外光谱及核磁共振氢谱对其结构进行了鉴定。采用失重法和电化学法研究了在0. 5mol·L~(-1)硫酸介质中其对碳钢试片的缓蚀性能,并通过吸附等温模型对缓蚀机理进行初步的探讨。结果表明,蛋氨酸衍生物的缓蚀效率约为90%,整体用量适中,是一种有望得到良好应用的绿色缓蚀剂。电化学分析表明,蛋氨酸衍生物为混合型缓蚀剂,其通过增大金属表面的电荷转移电阻而降低电化学腐蚀速率。     

异维A酸席夫碱酯的合成

以二环己基碳酰亚胺为脱水剂,4-二甲氨基吡啶为催化剂,异维A酸与对羟基苯胺发生酯化反应,生成异维A酸酯(1);1与醛反应,合成了4个异维A酸席夫碱酯,其结构经1H NMR和IR表征.     

天然海水中绿色碳钢缓蚀剂的研究

根据分子设计和官能团剪裁方法,结合有机缓蚀剂分子在金属表面和氧化膜表面的配位理论,选择葡萄酸钙,葡萄糖酸锌,硫酸锌,蒜素,丙烯酸聚合物,椰子油基烷醇酰胺,APG,OCTA,多聚磷酸钠等多种缓蚀剂成分,利用极化曲线法和重量法研究了上述缓蚀剂复配后对海水中碳钢的缓蚀作用,并由正交实验对筛选出的葡萄酸钙,硫酸锌和OCTA研究确定其以及相互之间的最佳复配比和协同效应,然后通过分段实验法再研究其最佳配方的后效能性,从而得到一种可生物降解的无磷高效绿色缓蚀剂.     

硫酸溶液中聚天冬氨酸对碳钢的吸附缓蚀性能

应用电化学极化曲线和交流阻抗研究聚天冬氨酸(PASP)对碳钢的缓蚀性能,讨论了PASP浓度和温度对缓蚀效果的影响.结果表明:PASP是一种以抑制阳极为主的缓蚀剂.在实验温度范围内,PASP在0.5mol/L硫酸溶液中对碳钢的缓蚀效率随着温度升高而降低,并以10℃时的缓蚀效果最好.在给定温度下,缓蚀率均随PASP浓度的增加而迅速增加,但当PASP质量浓度达到2.5g/L时,缓蚀率的增加趋于平缓,10℃下,缓蚀率的最高值可达80.33%(PASP 6.0g/L),PASP在碳钢表面的吸附基本服从Freund lich吸附等温式,PASP的加入增大了碳钢的腐蚀反应表观活化能.     

Corrosion inhibition studies on mild steel in HCl by a newly synthesized benzil monohydrazone based Schiff base

The corrosion inhibition effect of newly formulated Schiff base 2-((E)-((E)-2-hydrazone-1, 2-diphenylethylidene) amino phenol) (HDAP) ligand L derived from Benzil monohydrazone and 2-Aminophenol on mild steel in 1 ​M HCl was examined. Electrochemical (Tafel and EIS) and mass loss techniques were employed to evaluate its corrosion protection efficiency. The inhibition efficiency (η %) was elevated with raise in concentration of compound L.Maximum inhibition efficiency of 94.18% was obtained at 0.01 ​M concentration of HDAP from Tafel polarisation curve. From electrochemical impedance (EIS) studies, it was confirmed that increase in concentration of HDAP led to enhancement of the charge transfer resistance. Both physical and chemical types of adsorptions were observed for the Schiff base via π-bonding electrons which obey Langmuir adsorption isotherm. The SEM picture revealed development of a thin layer on metallic surface. Quantum chemical evaluations were conducted to find out the mechanism of corrosion retardation power of HDAP.     

甾体席夫碱荧光探针的微波合成及其对金属离子的识别

采用石胆酸与2-羟基-1-萘甲醛为原料,合成了一种新型甾体席夫碱结构荧光探针(L),其结构经NMR,IR,ESI-MS和元素分析表征。在pH 7.0缓冲溶液溶液中,探针L可以高选择性荧光识别Al^3+,检测限为8.0 nmol/L,适用范围为pH 6~10。当Al^3+与探针L配位时,生成1:1型配合物(L-Al^3+),在365 nm紫外灯照射下,由无色变成亮蓝色强荧光。     

含噻吩杂环Schiff碱及其配合物的合成与发光性质

在热乙醇中合成了2-乙酰基噻吩缩异烟酰肼及其与Cd(II)、Cu(II)和Zn(II)形成的三种配合物;利用元素分析、摩尔电导测定,以及红外光谱、紫外光谱和热分析确定了合成产物的组成和结构,并测定了配合物的组成及发光性质.结果表明,酰肼的配位方式的不同导致配合物呈现不同的发光性质.     

Synthesis of amino acid derivative Schiff base copper(II) complexes by microwave and wet mechanochemical methods

As resource- and time-saving and environmentally friendly synthetic methods than conventional one in a solution, microwave, and wet mechanochemical synthesis are tested for l-amino acid derivative Schiff base copper(II) complexes. Herein, we systematically compared efficiency (low-temperature, time, and yield (if possible to detect)) for both conventional solution method and microwave or mechanochemical methods. The wet mechanochemical synthesis promoted fast reaction (typically 20 ​min by mechanochemical vs 4 ​h by conventional) by a little amount of solvent for preparations of amino acid derivative Schiff base copper(II) complexes. New crystal structure of a five-coordinated square pyramidal copper(II) complex as one of the products of microwave method was also reported.     

Synthesis and physico-analytical studies of some novel ferrocenyl Schiff base derivatives

A series of ferrocenyl Schiff base derivatives was synthesized by condensation reactions of 1,1′-ferrocenedicarboxaldehyde and aromatic amines containing long chain alkyl groups as free ends which were characterized by their physical properties, elemental, FTIR, ¹H NMR, ¹³C NMR spectral and thermal analysis. The thermal behaviour of the synthesized compounds was studied by differential scanning calorimetry (DSC) which revealed that these compounds may exhibit mesomorphic properties. The DSC results of aromatic amines and ferrocenyl Schiff bases were compared to study the effects of structure, i.e. rigid core and terminal chain length, on the phase transition behaviour.     

Synthesis and characterization of some new Schiff base polymers

Seven Schiff base polymers poly 5,5^′-methylenebis(2-hydroxyacetophenone)semicarbazone (PHASC), poly-5,5^′-methylenebis(2-hydroxyacetophenone)thiosemicarbazone (PHATS), poly 6,6^′-methylenebis(2-hydroxynaphthaldehyde)1,2-propylenediimine (PHNPn), poly 6,6^′-methylenebis (2-hydroxynaphthaldehyde)1,3-propylenediimine (PHNPR), poly 6,6^′-methylenebis (2-hydroxy-naphthaldehyde)thiosemicarbazone (PHNTS), poly 6,6^′-methylenebis(2-hydroxy-naphthaldehyde)urea (PHNU) and poly-6,6^′-methylenebis(2-hydroxynaphthaldehyde)semicarbazone (PHNSC) were prepared by polycondensation of 5,5^′-methylenebis(2-hydroxyacetophenone) (MHA) or 6,6^′-methylenebis(2-hydroxynaphthaldehyde) (MHN) with semicarbazide, thiosemicarbazide, 1,2-propylenediamine, 1,3-propylenediamine or urea. The polymers were characterized by elemental micro-analysis, infrared and ultraviolet spectroscopy and viscosity measurements. The reduced viscosity of the polymers measured in dimethylformamide (DMF) was observed in the range 0.32-0.63 dl/g.     

冠醚化Schiff碱

综述了冠醚化Schiff碱的合成、配位和某些仿生性能的研究进展。     

Corrosion inhibition of mild steel by highly stable polydentate schiff base derived from 1,3- propanediamine in aqueous acidic solution

Recently, the hydrolysis of Schiff bases under experimental conditions gives suspicion for their corrosion inhibition performance. The current study employs a stable Schiff base namely, 2,2′-{propane-1,3-diylbis[azanylylidene (E) methanylylidene]}bis(6-methoxyphenol) (LPD) as corrosion inhibitor for mild steel (MS) in 1 M HCl solution. The presence of the characteristic peak of the imine group in UV-visible spectra was taken as an indicator for LPD stability in acidic media. The inhibition action was examined using electrochemical techniques including potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) besides gravimetric measurement. The inhibition efficiency reached 95.93 % for 0.75 mM LPD after 24 h of immersion at 25 °C. This high efficiency is owing to the presence of the characteristic imine group and other heteroatoms and π- electrons of the aromatic benzene rings. The mechanism of inhibition depends on adsorption phenomena on mild steel surface which obeys Langmuir isotherm model. The calculated values of adsorption equilibrium constant (K_ads), adsorption free energy ΔG_ads, adsorption enthalpy ΔH_ads and adsorption entropy ΔS_ads indicated spontaneous exothermic adsorption process of both physical and chemical nature. By rising temperature, the inhibition efficiency of LPD was decreased. The calculated activation energy was increased as the concentration of LPD increased. LPD was considered as a mixed-type inhibitor as indicated from PDP measurements. The obtained surface morphology and composition analysis using SEM/EDS, AFM and FTIR techniques ensures the high efficiency of LPD as corrosion inhibitor.     

Synthesis,characterisation and liquid crystalline behaviour of some lanthanides complexes containing two azobenzene Schiff base

Schiff base ligand N,N′-di-(4-butylsalicylidene)-1′,3′-diaminopropane [H₂L] was synthesised by the reaction of substituted azobenzene and 1,3-diaminopropane in 2:1 molar ratio. Four mononuclear lanthanide complexes of the type [Ln(H₂L)LCl] (Ln = LaIII, CeIII, SmIII and GdIII) were synthesised and characterised by ¹H,¹³C NMR, fourier transform infrared (FT-IR) spectroscopy, elemental analysis (CHNO), gas chromotography-mass, magnetic susceptibility and molar conductivity. Thermal properties of the title compounds were studied using the thermogravimetric analysis/differential scanning calorimetry (TGA/DSC) and optical polarising microscopy (OPM). The ligand and coordination compounds exhibit liquid-crystalline properties (smectic A).