Abstract: The chemical composition and method of the invention enable characterization of microscopic defects in membranes such as pinholes, cracks or fissures. The present invention, however, can be used to characterize defects on different types of porous and non-porous membranes used for diverse applications in various industries. It uses brightly fluorescing silica or silsesquioxane spheres prepared with pre-determined definitive and uniform sizes (15 nm-50 microns). The spheres' uniform, controlled size allows them to be used to characterize defects or holes in membranes based on a size exclusion mechanism. The spheres used are engineered to glow brightly when exposed to ultraviolet light in order to allow visual or highly sensitive fluorescence spectroscopy or microscopy to characterize the passage of the particles through defects or holes in a membrane and even identify where the defect is located.

Abstract: The invention discloses and claims a new class of chemical compositions with ideal sunscreen properties. The chemical composition comprises spherical particles between 200 nm and 10 microns in diameter prepared by an emulsion polymerization of tetraalkoxysilanes or organotrialkoxysilanes or organobridged trialkoxysilanes with a dye monomer bearing two or more alkoxysilyl groups attached to the bridging chromophore. The resulting spheres absorb ultraviolet light. The dye can be any organic chromophore capable of receiving multiple trialkoxysilyl groups resulting in multipoint covalent attachment that precludes leaching of the dye from the spheres. The formic acid-toluene-monomer emulsion polymerization allows for large-scale (>100 gram) synthesis of monodisperse particles under acidic, non-aqueous conditions without surfactants. The particles less than 1 micron in diameter are smooth as talc to the touch and will provide a smooth formulation for sunscreen creams or lotions.

Abstract: A method of preparing near net shape, monolithic, porous SiC foams is disclosed. Organosilicon precursors are used to produce polymeric gels by thermally induced phase separation, wherein, a sufficiently concentrated solution of an organosilicon polymer is cooled below its solidification temperature to form a gel. Following solvent removal from the gel, the polymer foam is pretreated in an oxygen plasma in order to raise its glass transition temperature. The pretreated foam is then pyrolized in an inert atmosphere to form a SiC foam.