Lee, T. Randall2017-07-252017-07-25August 2012012-08August 201http://hdl.handle.net/10657/1942Self-assembled monolayers (SAMs) generated from adsorption of the single-chained cholesterol-based and unsymmetrical double-chained cholesterol-based thiols on gold substrates were examined. The single-chained cholesterol-based thiols have a thiol headgroup, hydrocarbon spacer consisting of 3 – 12 methylene units, and a cholesterol tailgroup. The double-chained cholesterol-based thiols consist of a thiol headgroup and two tailgroups: an alkyl chain and a cholesterol-based moiety. Two series of single-component SAMs were formed from the cholesterol-based thiols. Analysis of the pure SAM shows that the added methylene spacer for the single-chained thiols allows for the formation of a better monolayer than that formed from thiocholesterol. The pure SAMs formed from the double-chained cholesterol-based thiols also produce a monolayer that is denser than the SAM generated from thiocholesterol, with interfacial properties resembling a SAM formed from normal alkanethiols. A series of binary SAMs generated from the single-chained cholesterol-based thiols and n-octadecanethiol exhibit properties of the cholesterol condensing effect. The SAMs were characterized using ellipsometry, contact angle goniometry, polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS), and X-ray photoelectron spectroscopy (XPS). Overall, these cholesterol-based adsorbates were used to generate dense monolayers despite a mixed composition of cholesterol moieties and trans-extended alkyl chains. The cholesterol condensing effect was observed in self-assembled monolayers for the first time.application/pdfengThe author of this work is the copyright owner. UH Libraries and the Texas Digital Library have their permission to store and provide access to this work. Further transmission, reproduction, or presentation of this work is prohibited except with permission of the author(s).CholesterolCondensing EffectMonolayerSelf-assembled monolayers (SAMs)Thiols2017-07-25Thesisborn digital