title: Interfacial behavior of OEG-linear dendron monolayers: aggregation, nanostructuring, and electropolymerizability.
abstract: We report on the interesting interfacial behavior of oligoethylene glycol or OEGylated linear dendron monolayers at the air-water interface as a function of (a) carbazole dendron generation, (b) the length of the OEG units, and (c) the surface pressure applied upon compression. Surface pressure-area isotherms, hysteresis studies, and isobaric creep measurement revealed a structure-property relationship consistent with the hydrophilic-lipophilic balance of a linear dendron with the OEG group serving as the surface anchor to the water subphase. AFM studies revealed that all the OEGylated carbazole dendrons self-assemble into spherical morphology at low surface pressures but form ribbonlike structures as the surface pressure is increased. This nanostructuring is primarily imparted by the increase in van der Waals forces with increasing amount of carbazole units per dendron generation on a hydrophilic mica surface. Further, electrochemical cross-linking of the carbazole molecules by cyclic voltammetery (CV) on doped Si wafer has enabled the formation of an LB film monolayer with a secondary level of organization in the monolayer imparted by the inter- and intramolecular cross-linking among the carbazole units. This study should provide a basis for monolayer film materials based on combining the LB technique and electrochemical cross-linking for nanostructuring superstructures at the air-water interface.
authors.affiliation: Department of Chemistry, University of Houston, Houston, Texas 77204-5003, USA.
authors.forename: Mary Jane
authors.initials: MJ
authors.lastname: Felipe
authors.forename: Nicel
authors.initials: N
authors.lastname: Estillore
authors.forename: Roderick Borong
authors.initials: RB
authors.lastname: Pernites
authors.forename: Thu
authors.initials: T
authors.lastname: Nguyen
authors.forename: Ramakrishna
authors.initials: R
authors.lastname: Ponnapati
authors.forename: Rigoberto C
authors.initials: RC
authors.lastname: Advincula
mesh_terms: D000388:Air; D050091:Dendrimers / Q000138:chemical synthesis / Q000737:chemistry*; D004563:Electrochemistry; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011092:Polyethylene Glycols / Q000138:chemical synthesis / Q000737:chemistry*; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D050091:Dendrimers; D014867:Water; D011092:Polyethylene Glycols