Chlorine-Resistant Polyamide Membrane via Fluorine Epoxy Integration
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Solution Overview
Problem
Polyamide-based water treatment membranes face challenges in achieving high salt rejection rates and permeate flux while maintaining chlorine resistance, with existing methods often compromising permeability due to the addition of a separate fluorine-containing coating layer.
Innovation Solution
Incorporating a fluorine compound with an epoxy group into the aqueous amine solution layer, allowing for interfacial polymerization with an acyl halide to form a polyamide layer with enhanced chlorine resistance and permeability, using a specific chemical formula for the fluorine compound with 4 to 20 carbon atoms.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate fluorine-containing coating layer is formed on the polyamide layer, then chlorine resistance is improved, but permeate flux is lowered
Solution Approach 1:
The patent combines the fluorine-containing component and amine component into a single aqueous solution layer before interfacial polymerization. This merging allows the fluorine compound to be incorporated into the polyamide layer structure itself rather than forming a separate coating, thereby maintaining chlorine resistance while preserving permeate flux through the integrated polyamide matrix.
Solution Approach 2:
The patent creates a composite polyamide layer containing both fluorine-containing compounds and amine compounds through interfacial polymerization. This composite structure integrates the chlorine resistance of fluorine compounds with the permeability characteristics of the polyamide matrix, eliminating the need for a separate coating layer and thus maintaining high permeate flux.
2Reliability
If the number of manufacturing processes is increased to form a coating layer, then chlorine resistance is improved, but manufacturing complexity is increased
Solution Approach 1:
The patent incorporates the fluorine-containing component into the aqueous solution layer before the interfacial polymerization step. This preliminary action ensures that the fluorine compound is already positioned within the forming polyamide layer, eliminating the need for subsequent separate coating processes and reducing manufacturing complexity while maintaining chlorine resistance.
Solution Approach 2:
The patent merges the fluorine-containing component incorporation step with the existing aqueous solution formation step. By combining these operations into a single process where both fluorine compounds and amine compounds are dissolved in the aqueous solution before polymerization, the patent reduces the number of manufacturing steps while achieving the desired chlorine resistance.
3Reliability
If a coating layer is formed to improve chlorine resistance, then product performance is improved, but permeability is reduced
Solution Approach 1:
The patent develops a composite polyamide layer where fluorine-containing compounds are integrated throughout the matrix structure. This composite material approach ensures that chlorine resistance is distributed throughout the entire polyamide layer rather than confined to a surface coating, thereby maintaining high permeability while providing comprehensive chlorine resistance.
Solution Approach 2:
The patent ensures that fluorine-containing compounds are distributed throughout the polyamide layer structure, providing local chlorine resistance at multiple locations within the membrane thickness. This distributed local quality approach maintains permeability by avoiding a dense surface coating while still providing effective chlorine resistance throughout the membrane structure.
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 method results in a water treatment membrane with superior chlorine resistance and permeate flux, maintaining high salt rejection rates and increasing the active surface area of the polyamide layer, thus improving both performance and longevity.
Implementation Method 1
forming a polyamide layer containing the fluorine compound by bringing an organic solution containing acyl halide into contact with the aqueous amine solution layer
Implementation Method 2
when external pressure having a level higher than that of osmotic pressure is applied, the solvent moves towards the solution having a low solute concentration, and such a phenomenon is known as reverse osmosis
Implementation Method 3
using an aqueous amine solution including a fluorine compound having an epoxy group in a terminal thereof and an amine compound
Data Source
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AI summary
The present disclosure relates to a method of manufacturing a water treatment membrane having high chlorine resistance and high permeability, the method including: forming an aqueous amine solution layer on a porous support, using an aqueous amine solution including a fluorine compound having an epoxy group in a terminal thereof and an amine compound; and forming a polyamide layer containing the fluorine compound by bringing an organic solution containing acyl halide into contact with the aqueous amine solution layer, and a water treatment membrane manufactured using the same.