Gas Separation Membrane Antioxidant Compatibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional gas separation membranes face durability issues due to oxidation, particularly with polyethylene oxide-based membranes that are prone to radical generation and degradation when exposed to oxidizing gases.
Innovation Solution
A gas separation membrane is developed with a functional layer containing a polyethylene oxide polymer and an antioxidant with an I/O value of 0.4 or less, which enhances durability by incorporating fat-soluble antioxidants like vitamin E, improving compatibility and resistance to oxidative degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a polyethylene oxide-based polymer is used in a gas separation membrane, then gas separation performance is improved, but durability against oxidizing gases deteriorates due to radical generation and oxidation
Solution Approach 1:
An antioxidant is introduced as an intermediary substance between the polyethylene oxide polymer and oxidizing gases. The antioxidant preferentially reacts with free radicals generated during oxidation, preventing these radicals from attacking and degrading the polymer chains. This mediator approach protects the polymer structure while maintaining gas separation functionality.
Solution Approach 2:
The invention converts the harmful oxidative process into a beneficial protective mechanism. By allowing controlled oxidation to occur, free radicals are generated that would normally attack the polymer. However, the antioxidant captures these radicals, transforming the harmful oxidation process into a protective system where the antioxidant sacrificially reacts instead of the valuable polymer.
2Reliability
If conventional antioxidants are used to protect the polymer, then oxidative degradation is reduced, but compatibility with the polyethylene oxide polymer deteriorates due to solubility issues
Solution Approach 1:
The invention changes the key parameter of antioxidant selection from general antioxidant activity to specific lipophilicity (I/O value). By selecting antioxidants with an I/O value of 0.4 or less, the patent ensures optimal compatibility with the polyethylene oxide polymer matrix. This parameter change resolves the solubility issue while maintaining protective function.
Solution Approach 2:
The invention applies the concept of local quality by selecting antioxidants with specific molecular characteristics (low I/O value indicating high lipophilicity) that match the local environment of the polymer matrix. This ensures the antioxidant is properly distributed and compatible within the specific polyethylene oxide matrix rather than using generic antioxidants.
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 exhibits improved durability and sustained performance in separating gases, such as CO2, by effectively preventing polymer deterioration from oxidizing gases, thus maintaining gas separation efficiency over time.
Implementation Method 1
deterioration of a polymer due to an oxidizing gas
Implementation Method 2
prone to radical generation and degradation when exposed to oxidizing gases
Implementation Method 3
Gas separation membrane that separates a specific gas component from a mixed gas
Implementation Method 4
porous support layer
Data Source
AI summary
Provided is a gas separation membrane which is excellent in durability with respect to deterioration of a polymer due to an oxidizing gas. A gas separation membrane according to the present disclosure includes: a separate functional layer that contains an antioxidant and a polymer which has a polyethylene oxide structure, the polymer which has the polyethylene oxide structure including an ethyleneoxy unit at a proportion of 57% or more in terms of weight ratio with respect to 100% of constitutional units of a main chain, and the antioxidant having an I/O value of 0.4 or less in an organic conceptual diagram.