# US 9,434,650 B2 · Ceramic material > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,434,650 B2 - Document ID: US9434650B2 - Status: Granted - Kind: B2 - Application number: 14/434,679 - Filed: 2013-10-09 - Published: 2015-10-01 - Granted: 2016-09-06 - Earliest claimed: 2012-10-09 - Assignees: Imperial Innovations Limited - Applicants: Imperial Innovations Limited - Inventors: Benjamin Francis Knatchbull Kingsbury; Zhentao Wu; Kang Li - Web page: https://patentgrep.com/patent/US9434650B2 ## CPC - C04B 35/10: based on aluminium oxide - B01D 39/2068: {Other inorganic materials, e.g. ceramics} - B01J 20/08: comprising aluminium oxide or hydroxide; comprising bauxite - B01J 20/28023: {Fibres or filaments (fibres or filaments in the form of membranes B01J20/28038; B01J20/28007 takes precedence)} - B01J 20/28033: {Membrane, sheet, cloth, pad, lamellar or mat} - B01J 20/3078: {Thermal treatment, e.g. calcining or pyrolizing} - B28B 11/243: {Setting, e.g. drying, dehydrating or firing ceramic articles (B28B11/242 takes precedence)} - C04B 35/62231: {based on oxide ceramics} - C04B 38/009: {Porous or hollow ceramic granular materials, e.g. microballoons (C04B18/027, C04B20/002 take precedence)} - C04B 2235/5436: micrometer sized, i.e. from 1 to 100 micron - C04B 2235/5445: submicron sized, i.e. from 0,1 to 1 micron - C04B 2235/6584: at an oxygen percentage below that of air - C04B 2235/6585: at an oxygen percentage above that of air - C04B: LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE {(roofing granules E04D7/005)}; CERAMICS (devitrified glass-ceramics C03C10/00); REFRACTORIES; TREATMENT OF NATURAL STONE - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - B28B: SHAPING CLAY OR OTHER CERAMIC COMPOSITIONS; SHAPING SLAG; SHAPING MIXTURES CONTAINING CEMENTITIOUS MATERIAL, e.g. PLASTER (foundry moulding B22C; working stone or stone-like material B28D; shaping of substances in a plastic state, in general B29C; making layered products not composed wholly of these substances B32B) ## Abstract The present invention relates to method for forming a porous ceramic material, the method comprising the steps of: providing a suspension of polymer-coated ceramic particles in a first solvent; contacting the suspension with a second solvent, whereby a ceramic material precursor is formed from the polymer and ceramic particles, heating the ceramic material precursor to at least partially decompose the polymer within the precursor into solid deposits, and then sintering the ceramic material precursor to form a porous ceramic material. ## Claims ### Claim 1 A method for forming a porous ceramic material, the method comprising the steps of: providing a suspension of polymer-coated ceramic particles in a first solvent; contacting the suspension with a second solvent, whereby a ceramic material precursor is formed from the polymer and ceramic particles, heating the ceramic material precursor in the presence of oxygen to at least partially decompose the polymer within the precursor into solid deposits, then sintering the ceramic material precursor under an inert atmosphere to form a porous ceramic material; and then heating the porous ceramic material under an oxygen-containing atmosphere to remove the solid deposits. ### Claim 2 (depends on 1) The method according to claim 1, wherein the inert atmosphere comprises nitrogen. ### Claim 3 (depends on 1) The method according to claim 1, wherein the ceramic particles comprise one or more metal oxides selected from Al2O3, ZrO, SiO2, CeO2, TiO2 and mixtures of two or more thereof. ### Claim 4 (depends on 1) The method according to claim 1, wherein the ceramic particles have a longest average diameter of from 5 to 0.01 microns. ### Claim 5 (depends on 1) The method according to claim 1, wherein the polymer comprises one or more invertible polymers. ### Claim 6 (depends on 1) The method according to claim 1, wherein the solid deposits comprise carbon deposits. ### Claim 7 (depends on 1) The method according to claim 1, wherein the first solvent comprises one or more of N-methyl-2-pyrrolidone, dimethyl sulphoxide, tetrahydrofuran and Dimethyl acetamide. ### Claim 8 (depends on 1) The method according to claim 1, wherein the second solvent comprises water. ### Claim 9 (depends on 1) The method according to claim 1, wherein the ceramic material precursor is sintered at a temperature of from 1200 to 1600° C. ### Claim 10 (depends on 1) The method according to claim 1, wherein the porous ceramic material is in the form of a hollow fiber. ### Claim 11 (depends on 1) The method according to claim 1, wherein the step of heating the ceramic material precursor comprises heating the ceramic material precursor in air at a temperature sufficient to cause at least partial decomposition of the polymer. ### Claim 12 (depends on 1) The method according to claim 1, wherein the porous ceramic material is a porous ceramic membrane. ### Claim 13 (depends on 1) The method of claim 1, wherein: the ceramic material precursor is sintered under an inert atmosphere at a temperature of from 1000 to 1300° C. to form the porous ceramic material; and the porous ceramic material is heated under an oxygen-containing atmosphere of greater than 600° C. to remove the solid deposits. ### Claim 14 (depends on 1) The method according to claim 1, wherein heating of the ceramic material precursor in the presence of oxygen to at least partially decompose the polymer within the precursor into solid deposits occurs as a multi-step operation. ### Claim 15 (depends on 1) The method according to claim 1, wherein the ceramic material precursor is heated in the presence of oxygen at a temperature of from 450 to 550° C. to at least partially decompose the polymer within the precursor into solid deposits. ### Claim 16 (depends on 1) The method according to claim 1, wherein during heating of the ceramic material precursor in the presence of oxygen to at least partially decompose the polymer within the precursor into solid deposits the temperature is ramped at a rate of from 1 degree/minute to 25 degrees/minute to a desired temperature, followed by ramping the temperature down from the desired temperature at a rate of from 1 degree/minute to 25 degrees/minute. ### Claim 17 A method for forming a porous ceramic material, the method comprising the steps of: providing a suspension of polymer-coated ceramic particles in a first solvent; contacting the suspension with a second solvent, whereby a ceramic material precursor is formed from the polymer and ceramic particles, heating the ceramic material precursor to at least partially decompose the polymer within the precursor into solid deposits by heating the ceramic material precursor under an inert atmosphere to decompose the polymer into the solid deposits comprising carbon deposits and then heating under an oxygen-containing atmosphere to partially remove the carbon deposits from the ceramic material precursor; and then sintering the ceramic material precursor to form a porous ceramic material. ### Claim 18 (depends on 17) The method of claim 17, wherein the ceramic material precursor is heated under the inert atmosphere at a temperature of from 1000 to 1300° C., and then heated under the oxygen-containing atmosphere at a temperature greater than 600° C. ### Claim 19 A method for forming a porous ceramic material, the method comprising the steps of: providing a suspension of polymer-coated ceramic particles in a first solvent; contacting the suspension with a second solvent, whereby a ceramic material precursor is formed from the polymer and ceramic particles, heating the ceramic material precursor to at least partially decompose the polymer within the precursor into solid deposits by heating the ceramic material precursor under an oxygen-containing atmosphere to partially decompose the polymer into the solid deposits and then under an inert atmosphere to fully decompose the solid deposits into carbon deposits, and then heating under an oxygen containing atmosphere to partially remove the carbon deposits from the ceramic material precursor; and then sintering the ceramic material precursor to form a porous ceramic material. ### Claim 20 A method for forming a porous ceramic material, the method comprising the steps of: providing a suspension of polymer-coated ceramic particles in a first solvent; contacting the suspension with a second solvent, whereby a ceramic material precursor is formed from the polymer and ceramic particles, heating the ceramic material precursor in a sealed oxygen-containing atmosphere to at least partially decompose the polymer within the precursor into solid deposits and to partially remove the solid deposits from the ceramic material precursor; and then sintering the ceramic material precursor to form a porous ceramic material once there is no oxygen remaining in the sealed atmosphere.