A DFT Study of the Bonding of Silanol Molecules to Oxidized Aluminum Surfaces
published: May 23, 2017, recorded: April 2017, views: 982
Report a problem or upload filesIf you have found a problem with this lecture or would like to send us extra material, articles, exercises, etc., please use our ticket system to describe your request and upload the data.
Enter your e-mail into the 'Cc' field, and we will keep you updated with your request's status.
One of the most promising novel corrosion resistant coatings, used for the protection of aluminum and its alloys, are hybrid sol-gel coatings, which combine the properties of organic and inorganic materials. Novel coatings are needed because traditional high-performance chromate conversion coatings are toxic and cancerogenic. One of the precursors for the synthesis of hybrid sol-gel coatings are silanol molecules and it is assumed that they react with the surface primarily via a condensation mechanism, as shown in figure 1a [1,2]. To shed some new light on the atomistic mechanism of bonding, the interactions of a simple silanol molecule (methylsilanetriol) with a model of the oxidized aluminum surface at the solid/vacuum interface, were studied within the framework of Density Functional Theory (DFT) utilizing periodic boundary conditions and the PBE exchange-correlation functional. The condensation reaction between two methylsilanetriols in the gas-phase (Figure 1b) was compared to the condensation reaction between the molecule and the oxidized surface (Figure 1a). According to the calculations both reaction energies are exothermic. The reaction of the molecule with the surface is by about 0.2 eV more exothermic, indicating that the bond between the molecule and the surface is slightly stronger than the bond between the silanol molecules themselves. Our calculations thus show that the currently proposed silanol–surface bonding mechanism is physically sound.
Download slides: ipssc2017_poberznik_oxidized_aluminum_surfaces_01.pdf (481.5 KB)
Link this pageWould you like to put a link to this lecture on your homepage?
Go ahead! Copy the HTML snippet !
Write your own review or comment: