Crosslinked Ion Exchange Membranes for Stability

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Solution Overview

Problem

Current composite anion exchange membranes (AEMs) suffer from poor chemical stability and high water absorption at elevated temperatures, leading to low conductivity and membrane dissolution, which limits their utility.

Innovation Solution

Crosslinking of ionomers within a composite matrix using heat, UV, IR post-treatment, or chemical agents, such as polyisocyanates and polyamines, to improve mechanical and thermal stability, reduce water swelling, and maintain ion conductivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If ion exchange polymers are used in composite anion exchange membranes, then excellent proton conductivities are achieved, but the membranes absorb excessive amounts of water at elevated temperatures

Engineering Contradiction:

ImproveconductivityVSAvoidwater absorption

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The patent applies parameter changes by modifying the chemical structure of the ion exchange polymer through crosslinking. This changes the physical and chemical parameters of the membrane, reducing water absorption while maintaining ion conductivity. The crosslinked structure alters the swelling behavior and thermal properties of the polymer matrix.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite membrane structure by combining ion exchange polymers with a porous substrate support. This composite approach allows the polymer to provide conductivity while the substrate provides structural stability and reduced water uptake at elevated temperatures.

Inventive Principle:

Principle #40Composite materials

2Reliability

If ion exchange polymers are used in composite anion exchange membranes, then excellent proton conductivities are achieved, but the membranes exhibit poor chemical stability and low anion conductivities

Engineering Contradiction:

ImproveconductivityVSAvoidchemical stability

Core Design Contradiction:

ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent modifies the chemical stability parameter by introducing crosslinks into the polymer structure. This structural modification increases resistance to chemical degradation in severe basic conditions while preserving the ion conduction pathways necessary for conductivity.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary crosslinking of the ion exchange polymer before final membrane assembly. This preliminary structural reinforcement prevents polymer degradation during subsequent membrane fabrication and operation, ensuring long-term chemical stability.

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If ion exchange polymers are used in composite anion exchange membranes, then the membranes are formed with cationic groups and mobile counter anions, but the membranes suffer from membrane dissolution and low stability in severe basic conditions

Engineering Contradiction:

Improveion exchange functionalityVSAvoidmembrane stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent creates a composite structure where ion exchange polymers are embedded in a porous substrate. This composite architecture provides the ion exchange functionality through the polymer while the substrate prevents membrane dissolution and enhances stability in severe basic conditions.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The patent changes the structural parameters of the ion exchange polymer through crosslinking, transforming it from a soluble linear polymer to an insoluble crosslinked network. This parameter change maintains ion exchange functionality while preventing membrane dissolution.

Inventive Principle:

Principle #35Parameter changes

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 crosslinked ion exchange membranes exhibit enhanced thermal and mechanical stability, reduced water swelling, and improved barrier properties, preventing membrane dissolution and maintaining conductivity.

Implementation Method 1

Crosslinking of ionomers within a composite matrix using heat, UV, IR post-treatment, or chemical agents, such as polyisocyanates and polyamines

Methodology Applied

Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 2

reduced water swelling, and improved barrier properties, preventing membrane dissolution

Methodology Applied

Scientific EffectSwelling reduction:

Data Source

PatentUS20240165602A1Ion exchange polymers and ion exchange membranes incorporating same

Publication Date: 2024.05.23 USA FORTESCUE IP INC

AI summary

An ion exchange membrane is provided which includes an ion exchange polymer that is partially cross-linked. The partially cross-linked ion exchange polymer will be more stable and will not be washed out over time. The ion exchange polymer may be UV or chemically cross-linked, wherein a cross-linking compound is added to the ion exchange polymer either before or after coupling to a support material. A support material may be made of, or be coated with, a cross-linking compound and the support material may initiate cross-linking proximal to the support material. The support material may be made of a material that chemically bonds with the ionomer.