07/13/2021
By Matthew Gage

The Kennedy College of Science and Department of Chemistry, invites you to attend a doctoral dissertation defense by Ruiyao Cui entitled “Boundary lubrication with branched fatty acids -- effects of adsorption conditions and sliding speed.” 

The defense will be held on Aug. 4 at 10 a.m. by Zoom. Please contact Matthew Gage for meeting information if you are interested in attending. The committee will be composed of Marina Ruths (chair), James Whitten, Juan Artes Vivancos and  James Reuther. A brief abstract is provided below.

Abstract: The friction of adsorbed layers of fatty acids with different chain structure (isostearic and isooleic acid) has been studied at different sliding speeds (micrometer/s and cm/s) with a Surface Forces Apparatus (SFA). Isooleic acid has an unsaturated chain with a methyl group located along the chain. The isostearic acid is a mixture of saturated methyl branched-chain fatty acid isomers. In both systems, the methyl group disrupts close packing of the molecules in the pure substance and when adsorbed on a surface (mica). A maximum in the friction force at cm/s speeds was identified for isooleic acid. The results are compared to previous observations at low speed for self-assembled surfactant films with different packing densities.

All interested students and faculty members are invited to attend.