Submitted to: Thin Solid Films
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/25/2010
Publication Date: 10/20/2010
Citation: Evans, K.O., Biresaw, G. 2010. Quartz crystal microbalance investigation of the structure of adsorbed soybean oil and methyl oleate onto steel surface. Thin Solid Films. 519:900-905. Interpretive Summary: A large quantity of surplus vegetable oils is produced in the U.S. annually. Therefore, there is a strong desire to find new uses for commodity oils so that farmers can get a good return on their crops and also reduce government subsidy. Lubrication application is one area where commodity oils may be used as farm-based products that can increase crop value. Vegetable oil-based lubricants have the potential of replacing many petroleum-based lubricants. In the work described here, the adorption of fatty acid esters (FAEs) on steel was explored using a new technique. It was found that there is a limit to the amount and thickness of the FAEs after adsorbing onto steel. This work extends our understanding of the behavior of lubricant additives.
Technical Abstract: The adsorption of soybean oil (SBO) and methyl oleate (MO) onto steel was investigated using quartz crystal microbalance with dissipation monitoring (QCM-D). Adsorption of both SBO and MO increased with increasing concentrations. At full surface coverage, SBO and MO formed rigid thin films and achieved a concentration of 0.15 and 0.17 nanomoles per cm2, respectively. Analysis of the QCM-D data showed that the structure of adsorbing molecules was tilted, with MO nearly parallel to the surface.