Chemical control over ceramic porosity using carboxylate-alumoxanes

A method of controlling the porosity and pore size distribution of a aluminum oxide based ceramic body comprising

• reacting boehmite with a carboxylic acid to produce carboxylate-alumoxane nanoparticles,
• drying the carboxylate-alumoxane nano-particles,
• re-dissolving the carboxylate-alumoxane nanoparticles in a solvent,
• evaporating the solvent so as to deposit the nanoparticles on a substrate, and
• firing the deposited nanoparticles at a temperature greater than 300° C. so as to form an aluminum oxide based ceramic body;
• wherein the ceramic body comprises the thermolysis product of a carboxylate-alumoxane represented by the formula [Al(O)x(OH)y(O2CR)z]n, wherein x is from 0 to 1.5, y is from 0 to 3, z is from 0 to 3, n is greater than 6, and R is hydrogen or an organic group;
• wherein the carboxylate is derived from a carboxylic acid selected from the group consisting of acetic acid, methoxyacetic acid, methoxyethoxyacetic acid, and methoxyethoxyethoxyacetic acid;
• and
• wherein the carboxylate-alumoxane is the reaction product of two or more carboxylic acids and boehmite.

A method of controlling the porosity and pore size distribution of a ceramic body comprising

• mixing two or more carboxylic acids to produce a carboxylic acid mixture;
• reacting boehmite with the carboxylic acid mixture to produce carboxylate-alumoxane nanoparticles,
• drying the carboxylate-alumoxane nano-particles,
• re-dissolving the carboxylate-alumoxane nano-particles in a solvent,
• drying the nano-particles, and
• firing the dried nano-particles at a temperature greater than 300° C. so as to form a ceramic body.

A method of controlling the porosity and pore size distribution of a ceramic body comprising

• reacting boehmite sequentially with two or more carboxylic acids to produce carboxylate-alumoxane nanoparticles,
• drying the carboxylate-alumoxane nano-particles,
• re-dissolving the carboxylate-alumoxane nano-particles in a solvent,
• drying the nano-particles, and
• firing the dried nano-particles at a temperature greater than 300° C. so as to form a ceramic body.

A method of controlling the porosity and pore size distribution of a ceramic body comprising:

• selecting a carboxylic acid composition that will result in a desired porosity and pore size distribution;
• reacting boehmite with said carboxylic acid composition to produce carboxylate-alumoxane nanoparticles,
• drying the carboxylate-alumoxane nano-particles,
• re-dissolving the carboxylate-alumoxane nano-particles in a solvent,
• drying the nano-particles, and
• firing the dried nano-particles at a temperature between 25° C. and 225° C. so as to form a ceramic body.

A method of controlling the porosity and pore size distribution of a ceramic body comprising:

• a) reacting boehmite or pseudo-boehmite with two or more carboxylic acids to produce carboxylate-alumoxane nanoparticles;
• b) drying the carboxylate-alumoxane nano-particles;
• c) re-dissolving the carboxylate-alumoxane nano-particles in a solvent;
• d) drying the nano-particles;
• and
• e) firing the dried nano-particles at a temperature greater than 300° C. so as to form a ceramic body.