Sulfonated Polyarylenesulfone Membranes for High-Flux Nanofiltration
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Solution Overview
Problem
Existing methods have not successfully produced nanofiltration membranes from poly(arylene sulfone) polymers that achieve both low molecular weight cut-off and high water permeation simultaneously.
Innovation Solution
A process involving the preparation of a membrane containing sulfonated polyarylenesulfone polymer and another polymer, using a reaction mixture comprising aromatic dihalogensulfones, aromatic dihydroxy compounds, carbonate compounds, and aprotic polar solvents, followed by separation and mixing with a pore-forming agent to enhance hydrophilicity and permeability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional poly(arylene sulfone) polymers are used to form nanofiltration membranes, then membrane structure can be established, but both low molecular weight cut-off and high water permeation cannot be achieved simultaneously
Solution Approach 1:
The patent uses composite materials by combining sulfonated polyarylenesulfone polymer with at least one further polymer (such as polyethersulfone, polyphenylene sulfone, or polysulfone) to create a membrane that achieves both low molecular weight cut-off and high water permeation simultaneously, resolving the contradiction between filtration precision and water transport efficiency
Solution Approach 2:
The patent applies parameter changes by introducing sulfonate groups into the polyarylenesulfone polymer structure, which modifies the chemical and physical properties of the membrane to enhance hydrophilicity and water permeation while maintaining appropriate molecular weight cut-off characteristics
2Reliability
If sulfonated polyarylenesulfone polymer is synthesized through conventional methods, then sulfonated polymer is obtained, but side reactions occur and control on degree of sulfonation is limited
Solution Approach 1:
The patent applies preliminary action by using pre-sulfonated aromatic dihalogen sulfone monomers (such as sulfonated dichlorodiphenylsulfone) as starting materials, which allows the sulfonation to be controlled during polymerization rather than occurring as side reactions after polymer formation, thereby achieving reliable control on the degree of sulfonation
Solution Approach 2:
The patent converts the potential harm of side reactions into benefit by designing the polymerization process to incorporate sulfonated monomers systematically, transforming what would be uncontrolled side reactions into controlled incorporation of functional groups, thereby achieving both reliable sulfonation control and elimination of harmful side reactions
3Manufacturing precision
If membrane production process is extended to achieve desired performance, then membrane properties are improved, but production time increases
Solution Approach 1:
The patent merges multiple process steps by combining polymerization and membrane formation into a more integrated process, where the sulfonated polyarylenesulfone polymer is prepared and directly used in membrane formation without extensive intermediate processing, thereby achieving desired membrane performance with reduced production time
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 process results in membranes with improved hydrophilicity, pure water permeability, and molecular weight cut-off, reducing production time and avoiding solvent mixture disposal issues.
Implementation Method 1
separating the at least one aprotic polar solvent from the second solution (S2) to obtain the membrane (M)
Implementation Method 2
mixing at least one further polymer (fP) with the first solution (S1) to obtain the second solution (S2), wherein in step iii) additionally at least one pore forming agent (pA) is mixed with the first solution (S1)
Data Source
AI summary
The present invention relates to a process for the preparation of a membrane (M) containing a sulfonated polyarylenesulfone polymer (sP) and at least one further polymer (fP), the membrane (M) obtained by the inventive process, a filtration (nano-, ultra- or microfiltration) system comprising the membrane (M), and the use of the membrane (M) in filtration processes.