title: Strong, low-density nanocomposites by chemical vapor deposition and polymerization of cyanoacrylates on aminated silica aerogels.
abstract: Strong polymer-silica aerogel composites were prepared by chemical vapor deposition of cyanoacrylate monomers onto amine-modified aerogels. Amine-modified silica aerogels were prepared by copolymerizing small amounts of (aminopropyl)triethoxysilane with tetraethoxysilane. After silation of the aminated gels with hexamethyldisilazane, they were dried as aerogels using supercritical carbon dioxide processing. The resulting aerogels had only the amine groups as initiators for the cyanoacrylate polymerizations, resulting in cyanoacrylate macromolecules that were higher in molecular weight than those observed with unmodified silica and that were covalently attached to the silica surface. Starting with aminated silica aerogels that were 0.075 g/cm(3) density, composite aerogels were made with densities up to 0.220 g/cm(3) and up to 31 times stronger (flexural strength) than the precursor aerogel and about 2.3 times stronger than an unmodified silica aerogel of the same density.
authors.affiliation: Materials Science and Engineering, University of Arizona, Tucson, Arizona 85721-0012, USA.
authors.forename: Dylan J
authors.initials: DJ
authors.lastname: Boday
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Stover
authors.forename: Beatrice
authors.initials: B
authors.lastname: Muriithi
authors.forename: Michael W
authors.initials: MW
authors.lastname: Keller
authors.forename: Jason T
authors.initials: JT
authors.lastname: Wertz
authors.forename: Kimberly A
authors.initials: KA
authors.lastname: Defriend Obrey
authors.forename: Douglas A
authors.initials: DA
authors.lastname: Loy
mesh_terms: D000179:Acrylates / Q000737:chemistry; D000327:Adsorption; D000588:Amines / Q000737:chemistry; D002384:Catalysis; D003487:Cyanoacrylates / Q000737:chemistry*; D005740:Gases; D005782:Gels; D053761:Nanocomposites / Q000737:chemistry*; D036103:Nanotechnology / Q000379:methods*; D011108:Polymers / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013696:Temperature; D013997:Time Factors; D014835:Volatilization
chemical_list: D000179:Acrylates; D000588:Amines; D003487:Cyanoacrylates; D005740:Gases; D005782:Gels; D011108:Polymers; D012822:Silicon Dioxide