Amorphous CO2 Separation Membrane With Metal-Ion Coordination

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Solution Overview

Problem

Existing separation membranes using silicon-based materials and organosilicon compounds with amino or urea groups suffer from low carbon dioxide permeability and CO2/N2 selectivity, with challenges in forming uniform pores and enhancing gas selectivity.

Innovation Solution

A separation membrane with a separation layer containing a polymer having an isocyanurate skeleton and siloxane bonds, along with metal ions, forming an amorphous structure that promotes high carbon dioxide permeability and CO2/N2 selectivity through coordinated bonding between nitrogen atoms and metal ions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If metal ions are doped into the separation layer to prevent pore densification, then heat resistance is improved, but pore size becomes small and CO2 permeability decreases

Engineering Contradiction:
Improveheat resistanceVSAvoidCO2 permeability
Core Design Contradiction:
TemperatureVSProductivity

Solution Approach 1:

The invention changes the chemical composition parameters by introducing isocyanurate groups and specific metal ions (Ni2+, Cu2+, Co2+, Zn2+) in controlled amounts. This creates a coordination polymer structure that maintains pore openness at high temperatures while providing sufficient CO2 permeability through optimized metal ion content (0.1-1.0 mmol/g dry polymer).

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention creates a composite coordination polymer structure combining organic isocyanurate groups with metal ions. This composite approach leverages the synergistic effects of both components: the organic framework provides structural stability and heat resistance, while the metal ions enhance pore stability and CO2 selectivity through coordination bonding.

Inventive Principle:
Principle #40Composite materials

2Reliability

If conventional organosilicon compounds with amino or urea groups are used, then the separation layer can be formed, but CO2 permeability and CO2/N2 selectivity are insufficient

Engineering Contradiction:
Improveseparation layer formationVSAvoidCO2 permeability and selectivity
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The invention changes the chemical structure by replacing conventional amino or urea groups with isocyanurate groups. This structural modification creates a more effective coordination polymer structure that simultaneously achieves sufficient CO2 permeability (≥300 GPU) and CO2/N2 selectivity (≥20), overcoming the limitations of previous organosilicon compounds.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If pores are formed in the separation layer, then gas permeability is improved, but uniform pore formation and gas selectivity enhancement become difficult

Engineering Contradiction:
Improvegas permeabilityVSAvoidpore uniformity and gas selectivity
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The invention changes the chemical composition by incorporating specific metal ions (Ni2+, Cu2+, Co2+, Zn2+) that form coordination bonds with isocyanurate groups. This creates a uniform coordination polymer structure with consistent pore characteristics, achieving both high gas permeability and enhanced CO2/N2 selectivity through controlled chemical interactions rather than random physical pore formation.

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 membrane achieves excellent CO2 permeability and selectivity, making it suitable for carbon dioxide recovery and storage from mixed gases and solvents.

Implementation Method 1

coordinated bonding between nitrogen atoms and metal ions

Methodology Applied
Scientific EffectCoordination bonding: Chemical Bonding

Implementation Method 2

A porous separation membrane separates a target substance by means of molecular sieving

Methodology Applied
Scientific EffectMolecular sieving: Molecular Sieve

Implementation Method 3

exhibits a high carbon dioxide permeability

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP4696404A1Separation membrane and method for producing same
Publication Date: 2026.02.18 SHIN ETSU CHEMICAL CO LTD
  • EP4696404A1 patent drawingFigure 1~2D
  • EP4696404A1 patent drawingFigure 3A~5
  • EP4696404A1 patent drawingFigure 6

AI summary

The present invention provides a separation membrane which comprises a separation layer that has an amorphous structure and contains: (A) a polymer that has an isocyanuric acid skeleton and a siloxane bond, and is obtained by polymerizing, for example, a precursor that contains a compound represented by general formula (1); and (B) a metal ion. (In the formula, X moieties each independently represent a group represented by formula (2) or a monovalent hydrocarbon group having 1 to 8 carbon atoms, and at least one of the X moieties represents a group represented by formula (2).) (In the formula, R1 moiety represents an alkylene group having 1 to 8 carbon atoms, R2 moieties each independently represent a monovalent hydrocarbon group having 1 to 8 carbon atoms, R3 moiety represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, and n represents an integer of 1 to 3. The line accompanied by a wiggly line indicates an atomic bond.)