INHIBITION EFFECT OF METAL-FREE PHTHALOCYANINE, COPPER PHTHALOCYANINE AND ZINC PHTHALOCYANINE ON MILD STEEL IN 1 mol/L H2SO4
无金属酞菁、酞菁铜和酞菁锌在1 mol/L H2SO4中对Q235钢的缓蚀作用

The inhibition effect of metal-free phthalocyanine(H_2Pc),copper pthalocyanine(CuPc) and zinc phthalocyanine(ZnPc) on mild steel in 1 mol/L H_2SO_4 was investigated by weight loss,electrochemical measurement and SEM observation.The weight loss results showed that the adsorption of these compounds obeyed to Langmuir isotherm;the potentio-dynamic curves indicated both anodic and cathodic processes of mild steel corrosion in H_2SO_4 were suppressed by phthalocyanines,the Nyquist diagram expressed as a capacity semi-circle,and charge transfer resistance R_t increased with the rising of pthalocyanines concentration;the surface morphology analysis of the tested samples also proved that the integrity of steel surface was enhanced and the corrosion was inhibited when added phthalocyanines;then the result of quantum chemical caluculation showed that the inhibition efficiency of phthalocyanines decreased with the increase of LUMO energy.