Composite Polyamide Membrane Phosphorous Monomer Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing composite membranes for fluid separations, such as reverse osmosis and nanofiltration, face limitations in flux and salt rejection efficiency due to the lack of effective integration of phosphorous-containing functional groups and amine-reactive species in the interfacial polymerization process.
Innovation Solution
The method involves applying polyfunctional amine and acyl halide monomers to a porous support for interfacial polymerization, with the inclusion of monomers containing phosphorous-containing functional groups and amine-reactive groups to enhance the formation of a thin film polyamide layer, improving membrane performance by increasing flux and salt rejection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional interfacial polymerization is used without phosphorous-containing functional groups, then the membrane formation process is simple, but the flux and salt rejection performance are limited
Solution Approach 1:
The patent combines phosphorous-containing functional groups with amine-reactive groups in a single monomer molecule, allowing both functions to be integrated into the polyamide structure during interfacial polymerization. This merging approach enhances salt rejection efficiency while avoiding the need for separate additive steps, thus resolving the contradiction between performance improvement and process complexity
Solution Approach 2:
The invention uses composite monomers that incorporate multiple functional groups (phosphorous-containing and amine-reactive) within a single molecular structure. This composite approach enables the formation of polyamide networks with enhanced functional properties for both salt rejection and flux, eliminating the need for separate functional additives and maintaining process simplicity
2Reliability
If phosphorous-containing functional groups are added to enhance salt rejection, then salt rejection improves, but the membrane flux may be reduced
Solution Approach 1:
The patent modifies the chemical parameters of the monomer by incorporating phosphorous-containing functional groups with specific molecular structures that optimize both salt rejection and flux. By carefully selecting and adjusting the chemical parameters of the functional groups, the invention achieves enhanced salt rejection without compromising flux, resolving the trade-off between these two performance parameters
Solution Approach 2:
The invention introduces phosphorous-containing functional groups at specific locations within the monomer structure where they can locally enhance salt rejection capability without interfering with the overall flux pathways. This localized functional placement allows different regions of the monomer to serve different functions, simultaneously optimizing both salt rejection and flux
3Reliability
If multiple functional groups are integrated into monomers, then membrane performance improves, but the monomer synthesis complexity increases
Solution Approach 1:
The patent incorporates phosphorous-containing functional groups and amine-reactive groups into the monomer structure during the monomer synthesis stage, rather than adding them separately during membrane formation. This preliminary action of integrating functional groups into the monomer allows for streamlined synthesis procedures and avoids subsequent complex modification steps, thus resolving the contradiction between performance enhancement and manufacturing ease
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 approach results in composite membranes with enhanced flux and improved salt rejection capabilities, particularly effective in reverse osmosis and nanofiltration applications, demonstrating increased permeability and reduced salt passage.
Implementation Method 1
The thin film layer may be formed by an interfacial polycondensation reaction between polyfunctional amine (e.g. m-phenylenediamine) and polyfunctional acyl halide (e.g. trimesoyl chloride) monomers which are sequentially coated upon the support from immiscible solutions
Implementation Method 2
conducting the interfacial polymerization in the presence of a monomer comprising at least one phosphorous-containing functional group or salt thereof and at least one amine-reactive functional group
Data Source
AI summary
A method for making a composite polyamide membrane comprising the steps 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 includes at least one of the following steps: i) conducting the interfacial polymerization in the presence of a monomer comprising at least one phosphorous-containing functional group or salt thereof and an at least one amine-reactive functional group; and/or ii) applying such a monomer to the thin film polyamide layer.