سال انتشار: ۱۳۸۶

محل انتشار: دهمین کنگره ملی خوردگی ایران

تعداد صفحات: ۱۲

نویسنده(ها):

M Lashgari – Department of Chemutry, InstituteforAdvancedStudies in Baric Sciences (lASBS),
M.R Arshadi – Department of Chemi!Jtry, Sharif University of Technology

چکیده:

Ahhough the effectiveness of corrosion inhibitors are normally investigated experimentally. the approach is often time consuming, wearisome and expensive.
Moreover, the fundamental investigations often need some sophisticated in struments capable of working in-situ on metal-solution interface. Thus, theoretical approaches have attracted many attentions in the last few years. In this work, molecular behavior of some aniline derivative as corrosion inhibitors of iron and copper in different corrosive media (HCI and H2S04) were investigated quantum electrochemically by some of our recently developed models based on density functional theory and cluster/polarized continuum approaches. In this regard, electrical dipole moment, charges on hetero atoms and acidic hydrogen, electronic chemical potential, and extent of charge transfer were determined for both neutral and protonated forms of the molecules inside electrical double layer and then correlated to their inhibitory POWCI’S. Some reasonably good correlations with opposite trends were observed for these media and discussed via ion-pair hypothesis and deprotonation phenomena. Comparing aniline adsorptions on iron and copper, the first was found more in chemical nature. Moreover, in both cases, the adsorptions were almost parallel (with corroding surfaces) and taken place through sp3 nitrogen lone pair
ofamino group. Finally, for the inhibition phenomena, a mechanism was proposed.