title: Elastomeric nanoparticle composites covalently bound to Al2O3/GaAs surfaces.
abstract: This article reports the modification of Al2O3/GaAs surfaces with multifunctional soft materials. Siloxane elastomers were covalently bound to dopamine-modified Al2O3/GaAs semiconductor surfaces using MPt (M = Fe, Ni) nanoparticles. The sizes of the monodisperse FePt and NiPt nanoparticles were less than 5 nm. The surfaces of the nanoparticles as well as the Al2O3/GaAs substrates were modified with allyl-functionalized dopamine that utilized a dihydroxy group as a strong ligand. The immobilization of the elastomers was performed via a hydrosilation reaction of the allyl-functionalized dopamines with the siloxane backbones. X-ray photoelectron spectroscopy (XPS) experiments confirmed the covalent bonding of the siloxane elastomers to the oxide layer on the semiconductor surface. Fourier transform-infrared reflection absorption spectroscopy (FT-IRRAS) measurements revealed that the allyl functional groups are bonded to the siloxane backbones. The FT-IRRAS data also showed that the density of the allyl groups on the surface was lower than that of the siloxane backbones. The mechanical properties of the surface-bound nanocomposites were tested using nanoindentation experiments. The nanoindentation data showed that the soft matrix composed of the elastomeric coating on the surfaces behaves differently from the inner, hard Al2O3/GaAs substrate.
authors.affiliation: Department of Chemistry, Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, Indiana 47907, USA.
authors.forename: Hyon Min
authors.initials: HM
authors.lastname: Song
authors.forename: Peide D
authors.initials: PD
authors.lastname: Ye
authors.forename: Albena
authors.initials: A
authors.lastname: Ivanisevic
mesh_terms: D017607:Aluminum Compounds / Q000737:chemistry*; D000537:Aluminum Oxide / Q000737:chemistry*; D001152:Arsenicals / Q000737:chemistry*; D020724:Elastomers; D005708:Gallium / Q000737:chemistry*; D007501:Iron / Q000737:chemistry; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure*; D009532:Nickel / Q000737:chemistry; D010984:Platinum / Q000737:chemistry; D011108:Polymers / Q000737:chemistry*; D012833:Siloxanes / Q000737:chemistry; D013053:Spectrophotometry; D013057:Spectrum Analysis; D013499:Surface Properties; D014867:Water / Q000737:chemistry
chemical_list: D017607:Aluminum Compounds; D001152:Arsenicals; D020724:Elastomers; D011108:Polymers; D012833:Siloxanes; C036925:elastomeric polymer; D014867:Water; C043055:gallium arsenide; D010984:Platinum; D009532:Nickel; D005708:Gallium; D007501:Iron; D000537:Aluminum Oxide