Reactive Support Layer Membranes for High-Flux Ion Separation
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Solution Overview
Problem
Existing separation membranes face challenges in achieving high water flux and ion retention rates while maintaining low energy consumption, with complex processes and increased membrane thickness being common issues.
Innovation Solution
A method involving an amino grafting reaction on a porous support membrane to create a reactive support layer, followed by interfacial polymerization with multi-membered acyl chloride oil phase monomers, reduces water permeation resistance and enhances the polyamide separation layer's integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If reverse osmosis membranes are used to ensure high desalination rate, then salt ion retention is improved, but energy consumption increases due to high operating pressure requirements
Solution Approach 1:
The patent changes the physical and chemical parameters of the support layer by introducing hydrophilic groups (such as carboxyl, hydroxyl, or amine groups) through chemical modification. This modifies the wettability and surface properties of the support layer, enabling better water permeation at lower operating pressures while maintaining high salt rejection rates, thus reducing energy consumption.
Solution Approach 2:
The patent creates a composite membrane structure combining a modified support layer with a polyamide active layer. The support layer is composite in nature, incorporating hydrophilic polymers or chemicals (such as polyethylene glycol, carboxymethyl cellulose, or aminated compounds) to enhance water permeability. This composite approach allows the membrane to achieve both high flux and high salt retention at lower pressures.
2Reliability
If nanofiltration membranes are used to remove bivalent ions and molecules with molecular weight greater than 200, then separation performance is improved, but water flux is reduced
Solution Approach 1:
The patent applies local quality modification by treating only the support layer with hydrophilic groups while maintaining the selective polyamide active layer intact. This localized modification enhances water permeation at the support layer without compromising the separation function of the active layer, thereby improving water flux while maintaining separation performance for bivalent ions and large molecules.
Solution Approach 2:
The patent utilizes and optimizes the porous structure of the support layer by modifying it with hydrophilic groups. The modification enhances capillary action and water transport through the pores while maintaining the pore size distribution necessary for supporting the active layer. This results in improved water flux through the membrane while preserving the nanofiltration separation capability.
3Productivity
If complex intermediate layers are added to improve water flux, then water permeation is enhanced, but manufacturing complexity increases
Solution Approach 1:
The patent extracts and eliminates the need for complex intermediate layers by directly modifying the support layer itself. Instead of adding separate intermediate layers with multiple components and steps, the invention modifies the support layer's chemical structure in place, simplifying the manufacturing process to a single modification step followed by standard polyamide layer formation.
Solution Approach 2:
The patent merges the function of the support layer and the hydrophilic modification into a single integrated component. Rather than having separate support layer and intermediate layer, the hydrophilic groups are incorporated directly into the support layer structure, combining structural support and water permeation enhancement functions into one layer, thereby reducing manufacturing complexity.
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 separation membranes with increased water flux and improved ion selectivity or retention rates, suitable for reverse osmosis and nanofiltration applications, while simplifying the production process.
Implementation Method 1
subjecting a porous support membrane to an amino grafting reaction to prepare a reactive support membrane
Implementation Method 2
subjecting an aqueous phase solution and an oil phase solution containing a multi-membered acyl chloride oil phase monomer to interfacial polymerization on the reactive support membrane
Data Source
AI summary
The present invention discloses a separation membrane based on a reactive support layer, a preparation method and an application, and belongs to the technical field of water treatment membranes. The preparation method includes: (1) subjecting a porous support membrane to an amino grafting reaction to prepare a reactive support membrane; and (2) subjecting an aqueous phase solution and an oil phase solution containing a multi-membered acyl chloride oil phase monomer to interfacial polymerization on the reactive support membrane to prepare a separation membrane based on a reactive support layer; where an aqueous phase monomer in the aqueous phase solution is a semi-aromatic amine or an aromatic amine. In the present invention, the porous support membrane is subjected to the amino grafting reaction to obtain the reactive support membrane, and the interface polymerization is carried out on a surface of the reactive support membrane. Due to the reactive support membrane, a structure of a formed polyamide separation layer can be changed, thereby improving the water permeability of a polyamide separation membrane and maintaining an ion retention property or the ion selectivity thereof. The method of the present invention has the advantages of a simple process, low requirements for equipment and convenience in industrial production, and the prepared high-performance separation membrane has a wide application prospect in the field of water treatment.