Projects / Programmes
Relacija med molekularno strukturo inhibitorjev, njihovo samoureditvijo na površini in korozijsko zaščito kovin (Slovene)
| Code |
Science |
Field |
Subfield |
| 1.04.01 |
Natural sciences and mathematics |
Chemistry |
Phyisical chemistry |
| Code |
Science |
Field |
| 1.04 |
Natural Sciences |
Chemical sciences |
Researchers (9)
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
90,753 |
Significance for science
New knowledge and concepts that emerged during the implementation of the research project, undoubtedly represent a significant advance in the understanding of how organic corrosion inhibitors act against corrosion at the molecular level. We have underlined some shortcomings and inconsistencies of the traditional concept of direct correlation between molecular electronic properties of organic inhibitors and their corrosion inhibition efficiency. This emphasizes the importance of a rigorous modeling of interactions between the components of the corrosion system in corrosion inhibition studies, including adequate description of the interaction between the inhibitor molecule and the surface at solid/liquid interface, because corrosion usually takes place at this phase boundary. We have developed a method that deals with this issue by means of an appropriate thermodynamic Born-Haber cycle, where the process is described by several elementary steps, which are selected so that each step can be adequately calculated/modeled. Such decomposition into elementary steps also allows a better understanding of the whole problem.
We have shown that in some cases the bonding of intact azole type corrosion inhibitor molecules to metal surfaces is rather weak, which is a very unexpected and surprising result, because if the bonding is weak then aggressive corrosive species would easily replace them from the surface. How can such molecules act against corrosion? What happens is that upon adsorption the corrosion inhibitor molecules may undergo some chemical modification, that is, some molecular bonds are broken and new ones are formed. These derived forms then bond considerably stronger to the surface and in several cases they are the actual species effective for inhibiting the corrosion. Triazoles and tetrazoles are examples, for which we showed to be active against corrosion in such "modified" form. On the other hand, the behavior of imidazole is different. Our results show that it is active against corrosion of copper in its neutral molecular form, whereas on iron it is active in the dehydrogenated form, namely, molecular adsorption is followed by dehydrogenation, where the C-H bond is cleaved. This is rather surprising, because on the basis of chemical intuition we would expect the cleavage of the N-H bond (i.e., detachment of acid hydrogen). Our findings therefore show that the surface chemistry of azole type corrosion inhibitors is very versatile, because these molecules can bind to the surface in many different ways. It all depends on the details and this is a strength of these molecules: in different conditions, they will adopt one of many possible forms and sustain various situations. On this basis we may conclude that we have significantly contributed to the understanding of the interaction between corrosion inhibitors and surfaces of metals. The implementation of the research project therefore represents a new and original approach to the study of corrosion inhibition at the molecular level.
We reasonably believe that the research carried out within this project will prove very useful in the development of predictive models for screening and designing new corrosion inhibitors with superior characteristics. It should be noted that any, even the smallest improvement of corrosion protection of metals would have large economic impact, since corrosion is associated with many technological areas; the corrosion is therefore a problem of major proportions. Effective corrosion inhibitors have been traditionally selected on the basis of empirical experimental testing of a large set of compounds. In contrast to such “trial and error” approach, a rational design of new corrosion inhibitors with superior inhibition properties would represent a breakthrough in the field of corrosion protection. We therefore expect that our established approach will have a significant influence on the further development of new and improved corrosion inhibitors.
Significance for the country
Our original approach, which has been developed during the implementation of the research project, contributes to the reputation of the Laboratory of Physical Chemistry at the Department of Physical and Organic Chemistry at the "Jozef Stefan" Institute and to the scientific recognition of Slovenia. Originality of our approach and recognition of our laboratory is particularly reflected by response in the international literature, because some pertinent published articles received more than ten citations in such a short time. Some members of the project team are among the most cited chemists in Slovenia (dr. Kokalj has over 3000 citations and prof. dr. Milošev over 2000). A large response was also achieved at international scientific conferences, as judged on the basis of well attended lectures and a number of questions that followed.
Three young researchers were also involved in this project within their doctoral dissertations (see issue-9). The project has therefore contributed to their learning and professional training. If the concepts that were developed within the project realization, turn to be useful for the design of new high-performance corrosion inhibitors, this will have a large economic importance, because any improvement in corrosion protection of metals has large economic impact and significance. This can be also of interest for certain chemical industrial enterprises in Slovenia.
Most important scientific results
Annual report
2009,
2010,
2011,
final report,
complete report on dLib.si
Most important socioeconomically and culturally relevant results
Annual report
2009,
2010,
2011,
final report,
complete report on dLib.si
