Presentation Information
[2I07]Palmitic acid adsorption on TiO2(110) submerged in liquid hexadecane
*Akitsu Sakata1, Shiho Moriguchi1,2, Hiroshi Onishi1,3 (1. Graduate School of Science, Kobe University, 2. Shimadzu Techno-Research Incorporated, 3. Institute for Molecular Science, National Institutes of Natural Sciences)
This study aimed to elucidate the adsorption mechanism of palmitic acid forming a monolayer on atomically flat titanium dioxide crystal surfaces in hexadecane, using AFM. In situ observations with contact mode AFM revealed that palmitic acid formed domain-like monolayers (1.5 nm high), and critically, mechanical external stimulus from AFM tip sliding induced this dissociative adsorption. This phenomenon can be explained by a hypothesis: as palmitic acid molecules in the lubricant reorient their molecular axes from surface-parallel to surface-perpendicular near the interface, the external stimulus disturbs the hexadecane layered structure, lowering the energy barrier for molecular axis rotation, thereby promoting adsorption.