University of Florida Research Foundation, Incorporated

Cabot Corporation

Wayne State University

James H Adair

Rajiv K Singh

Stephen A Costantino

Roger W Pryor

William Richard Eisenstadt

Sridhar Venigalla

Sherry S Staehle

Antony B Brennan

Seung-Beom Cho

A uniform suspension of ceramic powder and method for making the same. The suspension is prepared by mixing finely divided ceramic powder in an aqueous carrier fluid, combining with a dispersing agent, and alternatively, an organic binder when forming a slip. The ceramic powder has an average particle size of about 0.5 micron or less and is present in the suspension in a loading of up to 30% by volume of the total solids in suspension. A passivating agent is present in the carrier fluid in an amount of 0.5 to 5% by weight of the ceramic powder present for suspension and slip respectively. After the addition of a dispersant, the suspension has a Bingham yield point of less than 230 dynes/cm and an apparent viscosity of less than 3000 cps. A green layer produced from the slip exhibits a pore size of less than 0.5 micron.

Ceramic slip composition and method for making the same

A uniform suspension of ceramic powder and method for making the same. The suspension is prepared by mixing finely divided ceramic powder in an aqueous carrier fluid, combining with a dispersing agent, and alternatively, an organic binder when forming a slip. The ceramic powder has an average particle size of about 0.5 micron or less and is present in the suspension in a loading of up to 30% by volume of the total solids in suspension. A passivating agent is present in the carrier fluid in an amount of 0.5 to 5% by weight of the ceramic powder present for suspension and slip respectively. After the addition of a dispersant, the suspension has a Bingham yield point of less than 230 dynes/cm,and an apparent viscosity of less than 3000 cps. A green layer produced from the slip exhibits a pore size of less than 0.5 micron.

A method for producing phase-pure, monodispersed, single crystal alpha-alumina particles of controlled size and shape comprises the steps of providing an aluminum hydrous oxide precursor and a glycol solution, dispersing said precursor in said glycol solution to create a suspension, heating and stirring said suspension in a closed pressure vessel to produce alpha-alumina particles, cooling said suspension, and removing said alpha-alumina particles from said solution. Additionally nucleation seeds may be added to the solution. Control of size is a function of seeding concentration, and control of morphology is a function of stirring rate.

Method for controlling the size and morphology of alpha-alumina particles

A method for creating a patterned thin film of a high surface energy material on a substrate comprising the steps of creating a photomask pattern on the substrate using photolithography, providing an oppositely charged surface on the substrate and photomask, if such does not exist, from that of particles of the high surface energy material, removing the photomask and exposing the substrate to an aqueous colloidal suspension of particles composed of the high surface energy material to adsorb seed particles onto the surface of the substrate, or removing the photomask after adsorbing seed particles to the surface, and then depositing a uniform thin film of the high surface energy material by chemical vapor deposition onto the seeded substrate.

Patterned deposition of thin films

A method is provided for improving the scratch or surface wear resistance of substrates by embedding discrete, hard particles within the surface layer of the substrate. Discrete, hard particles are applied to the substrate surface and then embedded within and bonded to the surface layer of the substrate by softening the substrate surface layer by either thermal or solvent means. Suitable substrate materials include thermoplastics, thermoset plastics, polymers, glass, soft metals, and composites. Suitable hard particles include diamond, silicon dioxide, aluminum oxide, cubic boron nitride, boron carbide, silicon carbide, silicon nitride, tantalum carbide, titanium carbide, titanium nitride, tungsten carbide, and zirconia alloys containing at least one phase stabilization additive selected from the group yttrium, hafnium, calcium, magnesium, and cesium. Scratch resistant substrates or articles having discrete, hard particles embedded within the surface layer of the substrate or article are also provided. These substrates or articles essentially have the surface wear characteristics of the hard particles or material embedded within the surface layer. Thus, it is possible to prepare plastic materials or articles having significantly improved scratch or surface wear resistance without significantly increasing the weight or external dimensions of the plastic materials or articles.

Growing community of inventors

Gainesville, FL, United States of America

James H Adair