Reverse Osmosis Membrane with Controlled Pore Distribution
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Solution Overview
Problem
Conventional polyamide-based reverse osmosis membranes suffer from low initial permeation flux efficiency and deteriorating water purifying functions due to fouling, leading to degraded permeation flux and salt rejection over time.
Innovation Solution
A reverse osmosis membrane with a polysulfone layer having pores with diameters of 40 nm or greater accounting for less than 0.5% of total pores, formed using a mixed solvent with different solubility parameter values to enhance pore distribution and density, resulting in improved antifouling properties and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional polyamide-based reverse osmosis membrane is used, then the membrane can separate molecular-level materials and remove salts from salt water, but the initial permeation flux efficiency is low and water purifying function deteriorates over time
Solution Approach 1:
The patent applies porous materials by creating a polysulfone layer with controlled pore structures (pores of 40 nm or greater accounting for less than 0.5% of total pores) on the membrane surface. This porous structure provides antifouling properties while maintaining separation functionality, resolving the contradiction between durability and permeation flux efficiency
Solution Approach 2:
The patent uses composite materials by combining polysulfone layer with controlled pore distribution and polyamide active layer. The polysulfone layer with specific pore characteristics (pores ≥40 nm making up <0.5% of total pores) composite with the polyamide layer creates a membrane that maintains both high permeation flux and long-term durability, addressing the technical contradiction
2Reliability
If a polyamide-based reverse osmosis membrane is manufactured by forming a polyamide active layer on a microporous support, then the membrane can perform reverse osmosis separation, but solute or ionic compound adsorption occurs on the membrane surface causing pollution and degradation of water permeability characteristics
Solution Approach 1:
The patent creates a polysulfone layer with specific pore distribution (pores of 40 nm or greater accounting for less than 0.5% of total pores) that provides antifouling properties. This porous structure prevents solute and ionic compound adsorption while maintaining water permeability, resolving the contradiction between antifouling properties and water permeability characteristics
Solution Approach 2:
The patent changes the pore size parameter by specifying that pores of 40 nm or greater should account for less than 0.5% of total pores. This parameter control optimizes the balance between preventing fouling and maintaining water permeability, addressing the technical contradiction
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 superior antifouling properties, increased permeation flux, and enhanced salt rejection, maintaining performance over time without significant degradation, outperforming existing membranes in water treatment applications.
Implementation Method 1
a polysulfone layer formed on the porous support and having pores formed in a surface thereof, pores having a diameter of 40 nm or greater accounting for less than 0.5% of total pores
Implementation Method 2
when external pressure having a level greater 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
Data Source
AI summary
There is provided a reverse osmosis membrane including a porous support; a polysulfone layer formed on the porous support and having pores formed in a surface thereof, pores having a diameter of 40 nm or greater accounting for less than 0.5% of total pores; and an active layer.