摘要:
Nano- and micron sized metal oxide and mixed metal oxide particles are injected into a high temperature region wherein the temperature is between about 400° C. and less than 2000° C., and collected as particles or as coatings wherein a particulate nature is substantially maintained. The particles are altered in at least one of phase, morphology, composition, and particle size distribution, and may achieve further changes in these characteristics by coinjection of metal oxide precursor in liquid form.
摘要:
Manufactured articles are rendered identifiable as to their source or genuineness by incorporating one or more populations of up- and/or down-converting metal oxide or mixed metal oxides during or post manufacture. The nanoparticles exhibit emission of light upon irradiation by energy sources which allows comparison between the emission spectrum of an article with the emission expected of a genuine article or a material from a given manufacturing process, i.e. a batch of material.
摘要:
Liquid feed flame spray pyrolysis of solutions of a metal oxide precursor which is an alkoxide or C1-6 carboxylate and at least one second metal oxide precursor and/or second metal compound dissolved in oxygenated solvent by combustion with oxygen lead to the formation of sub-micron mixed-metal oxide powders not accessible by other processes or by the pyrolysis of metal chlorides or nitrates. The powders have numerous uses in advanced materials applications including particulate solid state lasers, advanced ceramic materials, and as catalysts in organic synthesis and automobile exhaust systems.
摘要:
Polyhedral silsesquioxane anions are economically prepared by reaction of a silica source derived from combusted organic material with a quaternary ammonium hydroxide compound. Reaction of the resulting anions with chlorosilanes may be effected in near stoichiometric fashion in organic solvent containing reactive quantities of organic acids such as formic acid. The functional groups on the resulting functionalized silsesquioxanes may be substituted for other functional groups by reaction with di- or polysiloxanes in the presence of a synthetic ion exchange resin.
摘要:
Methods of forming UV-absorbent transparent coatings and transparent substrates coated with the same allow for a relatively lower temperature cross-linkage reaction between a UV-absorbent compound and an epoxy-alkoxysilane. More specifically, UV-absorbent coatings on transparent substrates are formed by prepolymerizing a mixture consisting essentially of a benzophenone, an epoxy alkoxysilane and an organic catalyst at a temperature of between about 40° C. to about 130° C. and for a time sufficient such that between about 30% to about 70% of the epoxy alkoxysilane has been converted to a ring-opened oligomer or polymer. Such prepolymerized mixture may then be hydrolyzed and coated onto the surface of a transparent substrate, and thereafter cured at a temperature of less than about 200° C. for a time sufficient to cross-link the hydrolyzed alkoxysilane with itself and the glass surface. Most preferably, the prepolymerized mixture is hydrolyzed prior to being coated onto the substrate in an acidic alcoholic solution. Preferred for use in the present invention as a UV-absorbent compound is tetrahydroxybenzophenone. The preferred epoxy alkoxysilane is 3-glycidoxypropyl trimethoxysilane. It is especially preferred that prepolymerization be effected in the presence of an organic catalyst, such as triethylamine (TEA).
摘要:
Functionalized silsesquioxanes containing from 6 to 24 silicon atoms and minimally about 67 mol percent RSiO3/2 moieties where R is a phenyl group bearing a chemically reactive functional group are highly suitable for use as nanoparticles in producing highly ordered nanocomposites of many types, containing a high proportion of interphase. The nanocomposites have unusual physicochemical properties due to the use of uniform, highly functionalized nanoparticles.
摘要:
Inorganic/organic hybrid polymers containing silsesquioxane cages are robust and exhibit desirable physical properties such as strength, hardness, and optical transparency at infrared and ultraviolet wavelengths. The polymers are prepared by polymerizing functionalized polyhedral silsesquioxane monomers such as polyhedral silsesquioxanes bearing two complementarily reactive functional groups bonded to cage silicon atoms by means of spacer moieties. The spacer moieties allow for steric mobility and more complete cure than polyhedral silsesquioxanes bearing reactive functional groups bound directly to cage silicon atoms.
摘要:
A system for underfilling in a chip package includes an underfill mixture that ameliorates the CTE mismatch that typically exists between a packaged die and a resin-impregnated fiberglass mounting substrate. In one embodiment, the system includes an underfill mixture that comprises a principal underfill composition of a rigid octaaminophenyl silsesquioxane (OAPS) that is used as a curing agent for a tetrafunctional, low viscosity, and relatively rigid TGMX epoxy resin. An embodiment is also directed to the assembly of a flip chip package that uses the underfill mixture.