This work is devoted to the study of the inhibition of corrosion of mild steel(MS)in molar hydrochloric acid(1 mol·L-1 HCl)by two named quinoxaline derivatives namely,2-(2,4-dichlorophenyl)-1,4-dihydroquinoxaline...This work is devoted to the study of the inhibition of corrosion of mild steel(MS)in molar hydrochloric acid(1 mol·L-1 HCl)by two named quinoxaline derivatives namely,2-(2,4-dichlorophenyl)-1,4-dihydroquinoxaline(HQ)and 2-(2,4-dichlorophenyl)-6-methyl-1,4-dihydroquinoxaline(CQ).The inhibitory efficacy of HQ and CQ compounds is first evaluated using the gravimetric method and using electrochemical techniques(stationary and transient techniques).The results showed that our compounds are efficient corrosion inhibitors and the inhibition rates(ηEIS%)reached up to 91%and 94.2%at 10-3 mol·L-1 for HQ and CQ,respectively.The mentioned molecules are classified as mixed-type inhibitors.The adsorption of these inhibitors on the surface of steel in hydrochloric HCl 1 mol·L-1 medium obeys the Langmuir adsorption isotherm.The results of the scanning electron microscope(SEM)showed the formation of a protective film on the surface of the steel in the presence of the inhibitors studied.Elementary analysis is obtained by energy dispersive X-ray spectroscopy(EDS).The inhibition property was further elucidated by theoretical approaches such as:Density Functional Theory(DFT),quantum chemical descriptors(QCD),local reactive indices,solvent effect,theoretical complexation,Molecular Dynamic(MD)simulation,effect of temperature on adsorption energy(Eads),Radial Distribution Function(RDF),and Mean Square Displacement(MSD).The results of these approaches support the experimental results.展开更多
研究了硅酸与KOH,NaOH以及LiOH反应后所形成产物的吸水能力,结果表明:KOH与硅酸反应后的产物的吸水能力最强,其次是 NaOH,而 LiOH与硅酸反应的产物的吸水能力最弱.通过SEM/EDS对比研究了硅质集料在 LiOH,KOH,LiOH+KOH介质中的膨胀行为,...研究了硅酸与KOH,NaOH以及LiOH反应后所形成产物的吸水能力,结果表明:KOH与硅酸反应后的产物的吸水能力最强,其次是 NaOH,而 LiOH与硅酸反应的产物的吸水能力最弱.通过SEM/EDS对比研究了硅质集料在 LiOH,KOH,LiOH+KOH介质中的膨胀行为,结果表明: LiOH-硅酸反应生成的结构致密的非膨胀性产物硅酸锂L S H包裹在未反应的集料周围,阻止了碱-硅酸反应的继续进行,而 LiOH-硅酸反应过程本身不会引起膨胀;在LiOH存在时,硅酸与KOH反应后形成的 K S H中的 K+被Li+取代生成L S H,而L S H阻碍了碱-硅酸反应的继续进行,故 LiOH能够抑制碱-硅酸反应发生膨胀.展开更多
文摘This work is devoted to the study of the inhibition of corrosion of mild steel(MS)in molar hydrochloric acid(1 mol·L-1 HCl)by two named quinoxaline derivatives namely,2-(2,4-dichlorophenyl)-1,4-dihydroquinoxaline(HQ)and 2-(2,4-dichlorophenyl)-6-methyl-1,4-dihydroquinoxaline(CQ).The inhibitory efficacy of HQ and CQ compounds is first evaluated using the gravimetric method and using electrochemical techniques(stationary and transient techniques).The results showed that our compounds are efficient corrosion inhibitors and the inhibition rates(ηEIS%)reached up to 91%and 94.2%at 10-3 mol·L-1 for HQ and CQ,respectively.The mentioned molecules are classified as mixed-type inhibitors.The adsorption of these inhibitors on the surface of steel in hydrochloric HCl 1 mol·L-1 medium obeys the Langmuir adsorption isotherm.The results of the scanning electron microscope(SEM)showed the formation of a protective film on the surface of the steel in the presence of the inhibitors studied.Elementary analysis is obtained by energy dispersive X-ray spectroscopy(EDS).The inhibition property was further elucidated by theoretical approaches such as:Density Functional Theory(DFT),quantum chemical descriptors(QCD),local reactive indices,solvent effect,theoretical complexation,Molecular Dynamic(MD)simulation,effect of temperature on adsorption energy(Eads),Radial Distribution Function(RDF),and Mean Square Displacement(MSD).The results of these approaches support the experimental results.
文摘研究了硅酸与KOH,NaOH以及LiOH反应后所形成产物的吸水能力,结果表明:KOH与硅酸反应后的产物的吸水能力最强,其次是 NaOH,而 LiOH与硅酸反应的产物的吸水能力最弱.通过SEM/EDS对比研究了硅质集料在 LiOH,KOH,LiOH+KOH介质中的膨胀行为,结果表明: LiOH-硅酸反应生成的结构致密的非膨胀性产物硅酸锂L S H包裹在未反应的集料周围,阻止了碱-硅酸反应的继续进行,而 LiOH-硅酸反应过程本身不会引起膨胀;在LiOH存在时,硅酸与KOH反应后形成的 K S H中的 K+被Li+取代生成L S H,而L S H阻碍了碱-硅酸反应的继续进行,故 LiOH能够抑制碱-硅酸反应发生膨胀.
