Composite Polyamide Membrane with Sulfonyl Halide Groups
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Solution Overview
Problem
The search continues for new additives to further improve the performance of composite polyamide membranes used in fluid separations, particularly in reverse osmosis (RO) and nanofiltration (NF) applications, where existing membranes struggle with salt rejection and permeability.
Innovation Solution
The method involves applying polyfunctional amine and acyl halide monomers to a porous support and interfacially polymerizing them to form a thin film polyamide layer, with the option of conducting interfacial polymerization in the presence of an aromatic anhydride monomer containing a sulfonyl halide functional group or applying the aromatic anhydride monomer to the polyamide layer post-formation, enhancing membrane performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional polyfunctional amine and acyl halide monomers are used for interfacial polycondensation, then a thin film polyamide layer is formed, but salt rejection and permeability performance is insufficient
Solution Approach 1:
The patent modifies the chemical composition parameters of the monomers by introducing aromatic anhydride monomers with sulfonyl halide functional groups, transforming the polyamide layer's chemical structure to achieve superior salt rejection while maintaining permeability
Solution Approach 2:
The patent creates a composite membrane structure combining porous support with a thin film polyamide layer containing sulfonyl halide functional groups, integrating multiple material properties to simultaneously improve salt rejection and permeability performance
2Reliability
If existing membrane formulations are used, then membrane structure is maintained, but performance improvement is limited
Solution Approach 1:
The patent incorporates aromatic anhydride monomers with sulfonyl halide functional groups into the interfacial polycondensation process, preparing the membrane with enhanced functional groups during manufacturing to achieve improved performance without post-treatment
Solution Approach 2:
The patent adjusts the chemical formulation by introducing specific functional groups (sulfonyl halide) into the monomer system, changing the chemical parameters to enable better performance while maintaining manufacturability through standard interfacial polycondensation processes
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
This approach results in membranes that effectively reject salts and larger organic molecules, demonstrating improved salt rejection and permeability, as evidenced by lower salt passage and consistent performance in pressure testing compared to control membranes.
Implementation Method 1
applying polyfunctional amine and acyl halide monomers to a surface of a porous support and interfacially polymerizing the monomers to form a thin film polyamide layer
Data Source
AI summary
A method for making a composite polyamide membrane including the step of applying a polyfunctional amine monomer and polyfunctional acyl halide monomer to a surface of the porous support and interfacially polymerizing the monomers to form a thin film polyamide layer, wherein the method is characterized by: i) conducting the interfacial polymerization in the presence of an aromatic anhydride monomer include at least one sulfonyl halide functional group, or ii) applying the aromatic anhydride monomer to the thin film polyamide layer.