Compatibilized Composite Membrane for High-Selectivity Gas Separation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing polymeric gas separation membranes face a trade-off between permeability and selectivity, where high permeability results in low selectivity and vice versa, with most membranes limited by an upper bound in selectivity, and there is a need for a method to overcome this limit without synthesizing new polymers.
Innovation Solution
A semi-crystalline polymer blended membrane is fabricated by mixing thermoplastic resin, semi-crystalline polymer, and a compatibilizer, which is then extruded and drawn to create a thin film with a uniformly dispersed semi-crystalline polymer phase acting as an obstacle to gas permeation, enhancing selectivity while maintaining high permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a separation membrane has a high permeability, then the area of separation membrane required is reduced, but the selectivity is low
Solution Approach 1:
The invention uses a composite membrane system consisting of an amorphous thermoplastic resin matrix combined with dispersed semi-crystalline polymer particles. This composite structure allows the membrane to simultaneously achieve high permeability through the amorphous matrix and high selectivity through the semi-crystalline obstacles, breaking the traditional trade-off limit between these two properties.
Solution Approach 2:
The membrane structure incorporates regions with different properties: the amorphous thermoplastic resin provides high permeability pathways, while the dispersed semi-crystalline polymer particles create localized obstacles that enhance selectivity. This spatial differentiation of material properties allows simultaneous optimization of both permeability and selectivity.
2Manufacturing precision
If a separation membrane has a high selectivity, then the purity of product is enhanced, but the permeability is low
Solution Approach 1:
The composite membrane combines amorphous thermoplastic resin (providing permeability) with semi-crystalline polymer particles (providing selectivity). The amorphous matrix ensures sufficient gas transport while the semi-crystalline dispersed phase creates selective barriers, achieving both high selectivity and maintained permeability.
Solution Approach 2:
The membrane structure incorporates regions with different properties: the amorphous thermoplastic resin provides high permeability pathways, while the dispersed semi-crystalline polymer particles create localized obstacles that enhance selectivity. This spatial differentiation of material properties allows simultaneous optimization of both permeability and selectivity.
3Manufacturing precision
If semi-crystalline polymer is dispersed in amorphous thermoplastic resin to increase selectivity, then the dispersion uniformity must be controlled, but the interface adhesion is poor
Solution Approach 1:
A compatibilizer is introduced as an intermediary substance at the interface between the amorphous thermoplastic resin and semi-crystalline polymer particles. The compatibilizer improves interfacial adhesion and ensures uniform dispersion of the semi-crystalline phase, resolving the conflict between achieving uniform dispersion and maintaining interface adhesion.
Solution Approach 2:
The invention controls the size and distribution parameters of the semi-crystalline polymer particles through processing conditions and compatibilizer addition. By optimizing particle size (1-50 micrometers) and using appropriate compatibilizers, the system achieves both uniform dispersion and adequate interface adhesion.
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 high selectivity exceeding previous limits and sufficient permeability for practical use, with a simplified fabrication process that avoids complex methods like solution casting and allows for large-scale production, suitable for gas and liquid separation.
Implementation Method 1
the semi-crystalline polymer phase is evenly dispersed and morphologically controlled in the film, and works as an obstacle to diffusion of chemicals or gases, to thereby morphologically altering path length of permeants
Implementation Method 2
an appropriate amount of compatibilizer is added so that the semi-crystalline polymer has a uniform size and is in a well-dispersed state
Implementation Method 3
The chemicals or gases are separated according to interaction difference between the compatibilizer and permeant molecules, which induces diffusion time difference during which they pass the deformed path
Data Source
AI summary
Polymer composite including a compatibilizer and having selective permeability to chemical permeants due to interaction differences between the compatibilizer and the chemical permeants, includes 50-99 wt % of an amorphous thermoplastic resin selected from the group polyethylenepropylendienterpolymer, poly(1-(trimethylsilyl)-1-propyne), amorphous nylon, polystyrene and polycarbonate; 0.9-50 wt % of a semi-crystalline polymer selected from the group polyamide (nylons), polyethylene terephthalate, polybutylene terephthalate, polyethylene, polypropylene, polyetheretherketone, polyvinylidene fluoride, polytetrafluoroethylene, polyphenylene sulfide, and thermotropic or lyotropic liquid crystal polymer, and dispersed in the amorphous thermoplastic resin to provide a dispersed phase having an interface with the amorphous thermoplastic resin; and 0.1-10 wt % of a compatibilizer positioned at the interface of the dispersed phase with the amorphous thermoplastic resin and having different interactions with different chemical permeants so that the selective permeability of the polymer composite is affected.