Porous Ceramic Membrane Sintering for High Permeability
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Solution Overview
Problem
Conventional methods for forming porous ceramic membranes often result in low permeability due to over-densification during high-temperature sintering, which compromises both porosity and mechanical strength, making it difficult to achieve high permeability and selectivity simultaneously.
Innovation Solution
A method involving the controlled heating and sintering of ceramic precursors under inert and oxygen-containing atmospheres, using polymer-coated ceramic particles and phase inversion techniques to create a porous structure with maintained porosity and mechanical strength, allowing for higher sintering temperatures without over-densification, and subsequent removal of polymer deposits to achieve enhanced permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If high-temperature sintering is used to improve mechanical strength, then strength is improved, but porosity decreases due to over-densification
Solution Approach 1:
The patent applies preliminary action by incorporating a pore-forming agent into the ceramic precursor before sintering. This agent is designed to decompose at a specific temperature range (below the main sintering temperature) to create controlled pores in the ceramic matrix. By preparing the precursor with this built-in pore-forming mechanism, the final ceramic structure achieves both high strength from sintering and high porosity from the decomposed agent, resolving the contradiction between strength improvement and porosity maintenance.
2Manufacturing precision
If high-temperature sintering is used to achieve desired pore size, then pore size control is improved, but permeability decreases due to over-densification
Solution Approach 1:
The patent applies parameter changes by carefully controlling the decomposition temperature of the pore-forming agent to occur in a specific temperature range below the main sintering temperature. This temperature parameter control ensures that pores are formed before sintering densifies the structure, allowing precise pore size control while maintaining high permeability. The agent's decomposition temperature is specifically selected to create optimal pore structure without causing over-densification during subsequent high-temperature sintering.
3Ease of manufacture
If conventional sintering methods are used to form ceramic membranes, then manufacturing simplicity is maintained, but permeability is insufficient
Solution Approach 1:
The patent applies porous materials by incorporating a pore-forming agent that creates a controlled porous structure within the ceramic matrix during sintering. This agent forms a three-dimensional network of interconnected pores that maintain open porosity even after high-temperature treatment. The resulting ceramic membrane achieves high permeability through this engineered porous structure while maintaining manufacturing simplicity, as the porous structure is formed during the standard sintering process rather than requiring separate complex steps.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The method produces ceramic membranes with higher porosity and uniform pore structures, achieving permeation fluxes of at least 2000 L/m²h and maintaining mechanical strength, outperforming conventional techniques in terms of permeability and selectivity.
Implementation Method 1
heating the ceramic material precursor to decompose the polymer to form a porous ceramic material
Implementation Method 2
sintering the porous precursor structure under an inert atmosphere to form a dense ceramic body
Implementation Method 3
heating the dense ceramic body under an oxygen-containing atmosphere to remove the polymer deposits therefrom
Data Source
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AI summary
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, and then sintering the ceramic material precursor to form a porous ceramic material, wherein the step of heating the ceramic material precursor comprises i) 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, or ii) 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, or iii) heating the ceramic material precursor in a sealed oxygen-containing atmosphere whereby the solid deposits are partially removed from the ceramic material precursor, preferably wherein the sintering is conducted once there is no oxygen remaining in the sealed atmosphere, or iv) heating the ceramic material precursor in air at a temperature sufficient to cause at least partial decomposition of the polymer.