Adipic acid monolayer

Well-ordered SAMs of adipic acid were formed on the iron oxide/eaibon steel surface by the immersion method. This leads to ordered, robust monol eis bound to the surface in a tetradentate manner, since adipic acid is a dicarboxylic acid. Carbon steel was immersed in an aqueous solution containing 60 ppm of Cl and 50 ppm of adipic acid for 5 minutes, and was then taken out and rinsed in distilled water and heated in a hot air oven. The adipic acid monolayer on the iron oxide/carbon steel surface can withstand rinsing with water, concentrated acid and base exposure. Additionally, these monolayers are stable over the course of at least 1 week. 

As an example of SAMs, eorrosion inhibition by self-assembled films formed by adipic acid (AA) molecules on caibon steel surfaces is discussed below. SAMs of AA were formed on iron oxide/caibon steel surfaces by the immersion coating method. The metal was immersed in an aqueous solution containing 60 ppm of Cl (to initiate the corrosion process and the formation of iron oxide) in the absence and presenee of adipic acid. The formation, uniformity, ordering and bonding of the monolayers accompUshed by the immersion method have been evaluated by FTIR and AFM. The electrochemical properties of the unmodified and modified caibon steel surfaces were characterized by polarization study and EIS analysis to test the abiUty of the monolayer to reduce the corrosion of the surface. 

The presence of two peaks (2811 and 2726 cm ) in the region of 2700 to 3000 cm, corresponding to v CH2 sym and v CH2 unsym, indicated that the self-assembled monolayer film formed on metal surface (modified substrate) is stable, well ordered and strongly bound to the surface. The shifting of v C = 0 and v OH of the two carboxyl groups of adipic acid (1715 to 1597cm 3417 to 3414cm respectively) confirmed that adipic acid molecules are bound to the surface in a tetra dentate maimer. 

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