Composite Reverse Osmosis Membrane with Amphiphilic Block Copolymer Modification
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Solution Overview
Problem
Composite reverse osmosis membranes for seawater desalination face challenges in achieving high flux, desalination rate, boron removal rate, and contamination resistance simultaneously, with existing methods either compromising on flux or desalination rate.
Innovation Solution
A composite reverse osmosis membrane is developed with an amphiphilic block copolymer modification layer and a hybrid polyamide functional layer containing an ether with a cyclic structure, enhancing the binding force and hydrophilicity, thereby improving desalination rate and contamination resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a metal chelate containing a metal atom or metal ion and a bidentate ligand is used to enhance flux, then water flux is improved, but desalination rate decreases
Solution Approach 1:
The patent uses a composite polyamide layer formed by interfacial polymerization between a polyol-modified polysulfone support layer and a polyamine solution. This composite structure combines the hydrophilicity enhancement from polyol modification with the desalination capability of polyamide, achieving both high flux and high desalination rate simultaneously.
Solution Approach 2:
The patent modifies the support layer by incorporating polyols with specific molecular weights and hydroxyl values, changing the physical and chemical parameters of the membrane. This modification alters the surface properties and pore structure to optimize both water flux and salt rejection performance.
2Manufacturing precision
If a polyamide desalination layer is introduced to improve desalination rate, then desalination rate is improved, but flux may be reduced
Solution Approach 1:
The patent creates a polyamide layer with optimized local properties through controlled interfacial polymerization. The polyamide forms a selective barrier layer with appropriate thickness and crosslinking density, providing high desalination rate while maintaining sufficient water flux through proper structural design.
3Speed
If membrane hydrophilicity is enhanced to improve flux, then water flux is improved, but contamination resistance may deteriorate
Solution Approach 1:
The patent optimizes the hydrophilicity parameter by selecting polyols with specific hydroxyl values and molecular weights. This controlled modification enhances water flux while the subsequent polyamide layer formation maintains contamination resistance through the formation of a dense, crosslinked barrier.
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 membrane achieves a sodium chloride removal rate of over 99.85%, a boron removal rate of over 93%, and a water flux of 20-30 GFD with excellent contamination resistance, demonstrating improved performance across multiple criteria.
Implementation Method 1
the bidirectional diffusion of amine monomers and acyl chloride monomers in subsequent interfacial polymerization reaction may be effectively regulated
Implementation Method 2
which may effectively enhance the hydrophilicity of the desalination layer and consequently improves the water flux and anti-contamination capability
Implementation Method 3
Composite reverse osmosis membrane and preparation method therefor
Data Source
AI summary
The present disclosure relates to a composite reverse osmosis membrane and a preparation method therefor. The preparation method of the present disclosure can realize the preparation of a composite reverse osmosis membrane having a high flux, a high desalinization rate, a high deboration rate and high contamination resistance in a simple operation and high reaction efficiency manner.