PMP Separation Membrane Pore Control for Gas Permeability and Low Leakage
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Solution Overview
Problem
Existing separation membranes using polyolefin-based polymers face challenges in achieving both high gas permeability and low leakage due to issues with pore diameter and porosity, leading to inefficiencies in gas exchange processes.
Innovation Solution
A separation membrane composed of poly (4-methyl-1-pentene) with specific pore diameter and porosity ranges, along with a controlled variation in pore diameters across different regions, ensures both high gas permeability and low leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a thin dense layer of 2.0 μm or less is used to enhance gas permeability, then gas permeability is improved, but through pores (defects) are easily formed in the dense layer, causing high leakage
Solution Approach 1:
The membrane is designed with a dense layer having controlled pore structure and a support layer with different porosity characteristics. The dense layer maintains sufficient density to prevent leakage while the support layer provides structural integrity, creating local quality differences that resolve the contradiction between gas permeability and leakage prevention
Solution Approach 2:
The invention optimizes specific parameters including dense layer thickness (0.1-2.0 μm), porosity (30-70%), and average pore diameter (0.01-1.0 μm) of the support layer. By precisely controlling these parameters, the membrane achieves high gas permeability through the porous support layer while the thin dense layer prevents leakage, resolving the technical contradiction
2Reliability
If the pore diameter of the dense layer is reduced to less than 100 nm to reduce leakage, then leakage is improved, but gas permeability decreases
Solution Approach 1:
The membrane is segmented into two functional layers: a dense layer for leakage prevention and a porous support layer for gas permeability. This segmentation allows each layer to optimize its pore structure for its specific function, resolving the contradiction between preventing leakage and maintaining gas permeability
Solution Approach 2:
The support layer is designed as a porous material with controlled porosity (30-70%) and pore diameter (0.01-1.0 μm), providing high gas permeability pathways. The dense layer with thinner structure and smaller pores prevents leakage, while the porous support layer compensates for gas permeability, resolving the contradiction
3Productivity
If a porous surface structure is created to enhance gas permeability, then gas permeability is improved, but the solution easily leaks from the surface pores
Solution Approach 1:
Different regions of the membrane have different pore structures: the support layer has a porous structure for gas permeability while the dense layer has a thinner, less porous structure for leakage prevention. This local quality differentiation resolves the contradiction between gas permeability and leakage resistance
4Reliability
If a dense surface layer is formed to reduce leakage, then leakage is improved, but gas permeability becomes insufficient due to low porosity
Solution Approach 1:
The membrane is divided into a dense layer for leakage prevention and a porous support layer for gas permeability. The support layer compensates for the low porosity of the dense layer, ensuring sufficient overall gas permeability while the dense layer provides leakage protection
Solution Approach 2:
The membrane uses a composite structure combining a dense polymer layer with a porous support layer. This composite material approach allows the dense layer to provide leakage resistance while the porous support layer provides gas permeability pathways, resolving the contradiction between the two properties
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 membrane achieves enhanced gas permeability and reduced leakage, maintaining efficient gas exchange performance.
Implementation Method 1
a separation membrane containing poly (4-methyl-1-pentene) as a main component, with an average pore diameter converted from an NKP plot within a specific range, a porosity within a specific range
Data Source
Figure 1~2
Figure 3
AI summary
The present invention addresses the problem of providing a separation membrane that demonstrates low leakage while maintaining high gas permeability performance by using poly(4-methyl-1-pentene), which is excellent in solvent resistance and gas permeability. The present invention relates to a separation membrane which contains poly(4-methyl-1-pentene) as a main component, has an average pore diameter of 0.10-1.00 nm as converted from a NKP plot, and has a porosity of 40-70%. When the separation membrane is divided into five regions which are noted as 1-5, from one surface of the membrane in the direction of the thickness at equal intervals, the pore diameter variation coefficient αi is 0-150% in all of the regions 1-5.