Erik Hsiao1, Don Kim1, and Seong H. Kim2. (1) Chemical Engineering, The Pennsylvania State University, 123 Fenske Laboratories, University Park, PA 16802, (2) Penn State University, 118-B Fenske Lab, University Park, PA 16802-4400
As the size of mechanical devices now varies from the macroscale to the nanoscale, more innovative methods are needed to minimize wear caused by adhesion and friction on all scales. For this, we propose ionic polymer lubricant (IPL). The proposed IPL will have ionic interactions with the substrates which will provide moderate binding needed for boundary lubrication. This moderate binding allows for lateral mobility and thus self-healing, where self-healing is defined as the replenishment of the lubricant to the exposed surface. A cationic IPL (cIPL) with quaternary amine functional groups along with an anionic IPL (aIPL) with carboxylate functional groups will provide boundary lubrication for negative charged substrates and positive charged substrates respectively. In the nanoscale, the AFM was used to measure the film's disjoining pressure from which the lateral diffusion needed for self-healing can be calculated. In the macroscale, a ball on flat linear wear tester was used to measure the friction coefficient. The amount of ionic groups present in IPL can be varied to determine the optimum concentration necessary for strong interactions with the substrate while still allowing the lateral mobility needed for self-healing. Comparisons with Fomblin Z03 and Fomblin Zdol are made. The performance of IPL according to its film thickness, ionic group concentration, type of ionic groups, and substrates used is discussed.