Ion-Exchange Membrane Chemical Modification Prevents Delamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing ion-exchange membranes face issues with interfacial delamination and performance limitations, particularly in multi-layered structures, due to differences in ion exchanger layers, which affect their durability and current efficiency in electrochemical systems.
Innovation Solution
A method involving the chemical modification of perfluorinated sulfonic acid electrolyte membranes by substituting sulfonic acid groups with carboxyl groups through chlorination, nitrilation, and hydrolysis, creating a double-layered structure that prevents interfacial resistance and delamination.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a different type of ion exchanger layer is formed using thermal compression or coating, then the membrane structure is created, but interfacial delamination occurs
Solution Approach 1:
The patent merges the sulfonic acid layer and carboxyl layer into a single integrated membrane through in-situ chemical modification. The carboxyl groups are formed directly within the sulfonic acid membrane matrix, creating a unified structure without separate layers that would require thermal compression or coating, thereby eliminating interfacial delamination issues while maintaining the dual-functionality of the membrane
Solution Approach 2:
The patent applies preliminary chemical modification to the sulfonic acid membrane before final membrane assembly. By pre-forming carboxyl groups within the sulfonic acid membrane structure through controlled chemical reactions (chlorination followed by cyanide treatment and hydrolysis), the membrane achieves its dual-layer functionality intrinsically, preventing subsequent delamination issues that would arise from assembling separate layers
2Productivity
If sulfonic acid groups are substituted with carboxyl groups through chemical modification, then current efficiency is improved, but membrane structure stability may be affected
Solution Approach 1:
The patent applies local quality modification by converting only specific sulfonic acid groups to carboxyl groups rather than uniformly modifying the entire membrane. By controlling the chemical modification conditions (chlorination time, cyanide concentration, temperature), the patent creates localized regions with different functional groups within the same membrane, achieving high current efficiency in modified regions while preserving structural stability in unmodified regions
Solution Approach 2:
The patent utilizes parameter changes to control the extent of sulfonic acid group substitution. By adjusting reaction parameters such as chlorination time, temperature, and reagent concentration, the patent achieves partial substitution of sulfonic acid groups with carboxyl groups, optimizing both current efficiency and membrane stability by maintaining a balanced composition of both functional groups
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 approach enhances the durability and current efficiency of ion-exchange membranes by forming a stable double-layered structure with controlled chlorination, improving their performance and preventing interfacial delamination in electrochemical systems.
Implementation Method 1
a) chlorinating sulfonic acid groups in a perfluorinated sulfonic acid electrolyte membrane
Implementation Method 2
b) nitrilating the chlorinated electrolyte membrane
Implementation Method 3
c) hydrolyzing the nitrilated electrolyte membrane
Implementation Method 4
A cation exchange membrane has negatively charged functional groups, permeates only cations by electrical attraction
Implementation Method 5
blocks the movement of anions by electrostatic repulsion
Data Source
AI summary
The present inventive concept relates to a method of preparing an ion-exchange membrane using a chemical modification and an ion-exchange membrane prepared thereby. More specifically, the present inventive concept relates to a method of preparing an ion-exchange membrane, which is characterized by modifying sulfonic acid groups of a perfluorinated sulfonic acid electrolyte membrane with carboxyl groups and includes chlorinating sulfonic acid groups of a perfluorinated sulfonic acid electrolyte membrane; nitrilating the chlorinated electrolyte membrane; and hydrolyzing the nitrilated electrolyte membrane, and an ion-exchange membrane chemically modified thereby.