title: Photoinduced deprotection and ZnO patterning of hydroxyl-terminated siloxane-based monolayers.
abstract: Trimethoxy-[11-(2-nitrobenzyloxy)undecyl]silane (1) and trimethoxy-[17-(2-nitrobenzyloxy)heptadecyl]silane (2) have been used for the covalent assembly of siloxane-based photopatternable monolayers. Exposing the monolayers to UV light (312 +/- 10 nm) results in the generation of reactive hydroxyl-terminated monolayers without affecting the film quality. The new monolayers, deprotection chemistry, and the effect of photoinduced headgroup lift-off on the monolayer microstructure have been studied in detail by a full complement of physicochemical techniques, including optical (UV-vis) spectroscopy, ellipsometry, aqueous contact angle (CA) measurements, X-ray photoelectron spectroscopy (XPS), synchrotron X-ray reflectivity (XRR), and atomic force microscopy (AFM and AFM-force spectroscopy). AFM-force spectroscopy was used to analyze hydrogen-bond interactions as a function of the nature of the solid-liquid interface. AFM-force spectroscopy indicates a hydrogen-bond energy for photodeprotected monolayers of 8.2 kJ mol(-1) (approximately 2 kcal mol(-1)). Scanning electron microscopy (SEM) revealed that treatment of photopatterned monolayers with ZnEt2 solutions resulted in well-defined approximately 2 microm x 2 microm features of 10 A thick ZnO layers.
authors.affiliation: Department of Organic Chemistry, Department of Chemical Research Support, The Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Zubkov
authors.forename: André C B
authors.initials: AC
authors.lastname: Lucassen
authors.forename: Dalia
authors.initials: D
authors.lastname: Freeman
authors.forename: Yishay
authors.initials: Y
authors.lastname: Feldman
authors.forename: Sidney R
authors.initials: SR
authors.lastname: Cohen
authors.forename: Guennadi
authors.initials: G
authors.lastname: Evmenenko
authors.forename: Pulak
authors.initials: P
authors.lastname: Dutta
authors.forename: M E
authors.initials: ME
authors.lastname: van der Boom