Microporous Polyolefin Membrane for Hydrophilic Resin Loading
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Solution Overview
Problem
Existing composite membranes made from hydrophobic polyolefin resins face challenges in loading hydrophilic resin compounds due to high water repellency, requiring hydrophilization treatments that can weaken the membrane and increase production costs, while methods to increase pore diameter or porosity often lead to reduced dynamic strength and membrane tearing.
Innovation Solution
A microporous polyolefin membrane with an average pore diameter of 1 nm to 50 nm, porosity of 50% to 78%, and thickness of 1 μm to 12 μm, which can be impregnated with a mixed solution of ethanol and water without hydrophilization treatment, allowing for efficient loading of hydrophilic resin compounds under atmospheric pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If hydrophilization treatment is applied to increase loading of hydrophilic resin compounds, then the loading efficiency is improved, but the membrane strength is weakened and production cost increases
Solution Approach 1:
The invention changes the pore size parameter to a specific range (1 nm to 50 nm) to enable effective capillary action for aqueous solutions. This parameter optimization allows the membrane to load hydrophilic resin compounds without requiring hydrophilization treatment that would compromise membrane strength.
2Difficulty of detecting and measuring
If pore diameter or porosity is increased to improve permeability, then the permeability is improved, but the dynamic strength is reduced and membrane tearing occurs
Solution Approach 1:
The invention optimizes the pore diameter to a specific range (1 nm to 50 nm) that balances permeability and strength. This parameter change enables effective capillary action for aqueous solutions while maintaining sufficient membrane strength to prevent tearing during handling and use.
3Ease of manufacture
If conventional impregnation methods are used on hydrophobic membranes, then the production cost is reduced, but the loading efficiency of hydrophilic resin compounds is poor
Solution Approach 1:
The invention changes the pore diameter parameter to enable capillary action that overcomes the hydrophobicity of polyolefin membranes. This parameter optimization allows conventional impregnation methods to effectively load hydrophilic resin compounds without requiring expensive hydrophilization treatments.
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 solution enables effective permeability of aqueous solutions with high water concentration and surface free energy into the membrane, enhancing the loading of hydrophilic resin compounds without compromising the membrane's dynamic strength or increasing production costs.
Implementation Method 1
the pores of which can be satisfactorily loaded with a hydrophilic resin compound... when a mixed solution of ethanol and water (volume ratio 1/2) is dripped onto a surface of the microporous polyolefin membrane... a contact angle θ1 between the droplet and the surface is 0 to 90 degrees 1 second after the dripping
Data Source
AI summary
A substrate for a composite membrane includes a microporous polyolefin membrane for carrying a hydrophilic resin compound within the pores of the microporous membrane wherein: the average pore diameter is 1 nm to 50 nm; the porosity is 50% to 78%; the membrane thickness is 1 μm to 12 μm; and, when a mixed solution of ethanol and water (volume ratio 1/2) is dripped onto a surface of the microporous polyolefin membrane which has not undergone hydrophilization treatment, the contact angle θ1 between the droplet and the surface is 0 to 90 degrees 1 second after the dripping, and the contact angle θ2 between the droplet and the surface is 0 to 70 degrees 10 minutes after the dripping, and the rate of change of the contact angle ((θ1−θ2)/θ1×100) is 10 to 50%.