Microporous Polymer Membranes With Amidoxime Pores for Ion Selectivity

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing microporous polymer membranes face challenges in achieving high fractional free volume and transport selectivity, particularly in applications requiring highly conductive, ion-selective cation exchange membranes for electrochemical devices, due to their rigid backbones and limited control over membrane architecture.

Innovation Solution

The introduction of amine-functionalized and amidoxime-functionalized monomer segments into microporous polymers, combined with 1,4-dicyanoarenes, creates polymers with tailored architectures that enhance transport properties by frustrating chain packing and introducing high-pH stable, ionizable amidoxime pore functionality, allowing for controlled membrane processing and performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If rigid backbones are used in microporous polymer membranes, then structural stability is improved, but transport selectivity and fractional free volume are limited

Engineering Contradiction:

Improvestructural stabilityVSAvoidtransport selectivity

Core Design Contradiction:

Stability of the object's compositionVSManufacturing precision

Solution Approach 1:

The polymer backbone is segmented into rigid aromatic units connected by flexible alkyl chains, creating a segmented structure that combines structural stability with controlled porosity. The rigid segments provide mechanical strength while the flexible segments create free volume and transport pathways.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs composite monomer structures combining rigid aromatic rings (for stability) with flexible alkyl chains and functional groups (for transport properties). This composite approach at the molecular level achieves both structural integrity and enhanced transport selectivity.

Inventive Principle:

Principle #40Composite materials

2Ease of manufacture

If conventional microporous polymers are used, then membrane formation is simplified, but control over membrane architecture is limited

Engineering Contradiction:

Improvemembrane formationVSAvoidcontrol over membrane architecture

Core Design Contradiction:

Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

Different monomer units within the polymer provide different local properties: rigid units for structural framework, flexible units for porosity, and functional units for specific transport properties. This local differentiation enables precise control over membrane architecture while maintaining ease of manufacture through conventional polymerization.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent controls membrane architecture by varying parameters such as monomer composition ratios, chain length of flexible segments, and functional group types. These parameter changes allow tuning of pore size, fractional free volume, and transport selectivity without changing the fundamental membrane formation process.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If high fractional free volume is achieved, then transport selectivity is improved, but membrane stability decreases

Engineering Contradiction:

Improvetransport selectivityVSAvoidmembrane stability

Core Design Contradiction:

Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The segmented architecture separates the functions of structural support (rigid segments) and transport (flexible segments with high free volume). This segmentation allows the membrane to achieve high fractional free volume for transport selectivity while rigid segments maintain overall structural stability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The composite monomer design combines rigid stabilizing units with flexible high-free-volume units in the same polymer chain. This molecular-level composite structure enables simultaneous achievement of membrane stability and high transport selectivity through optimized composition ratios.

Inventive Principle:

Principle #40Composite materials

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

These polymers exhibit improved transport selectivity and stability in electrochemical cells, leading to extended cycle-life and higher round-trip energy efficiency, particularly in Zn-based electrochemical cells.

Implementation Method 1

introducing high-pH stable, ionizable amidoxime pore functionality

Methodology Applied

Scientific EffectIon exchange: Ion Exchange

Implementation Method 2

microporous polymers, whose glass transition temperatures are typically above their decomposition temperatures

Methodology Applied

Scientific EffectMicroporosity: Porosity

Data Source

PatentUS20250236705A1Diversity-oriented polymers of intrinsic microporosity and uses thereof

Publication Date: 2025.07.24 RGT UNIV OF CALIFORNIA

AI summary

The present disclosure is directed to microporous ladder polymers containing amine-functionalized monomer segments, amidoxime-functionalized monomer segments, or a combination thereof. Monomer compounds for preparation of the polymers are also described, as well as membranes and electrochemical cells containing the polymers.