Improvement of anticorrosive properties of zinc-rich coatings using nanocomposites

Iranian researchers from Amirkabir University of Technology used nanotechnology to improve the properties of coatings rich in zinc.
The researchers believe that the two properties of high electrical conduction and low permeability of the suggested nanocomposite are the cause of the improvement.
Coatings rich in zinc contain high amount of zinc powder due to the nature of their performance. This high percentage results in reduction in the applicable properties of the coating such as adhesion, mechano-physical properties and creation of pores. The presence of pores results in fast consumption of the active zinc powder and it decreases the life of the coating. In this research, it was tried to improve barrier effect properties in the coating by using polyaniline – clay nanocomposite while its other properties remain unchanged.
According to Dr. Morteza Ebrahimi, a member of the Scientific Board of Amir Kabir University of Technology, the life of coatings enriched with zinc can be significantly increased in case this nanocomposite is used in the production of the coatings. This fact results in the reduction in the number of paintings, increasing the period between maintenance and replacement of the coating, and finally, it decreases the costs.
Results of the research show that in case only one percent of zinc powder is replaced with polyaniline – clay nanocomposite produced in this research, passage of vapor decreases more than 50%. In addition, the open circuit potential of steel samples with the coating modified with the proposed nanocomposite will be at safe zone for a long time (about 180 days).
Results of the research have been published in Progress in Organic Coatings, vol. 77, issue 8, 2014, pp. 1299-1308).