Microporous Organic Membrane Fabrication via Sacrificial Layer

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Solution Overview

Problem

Existing methods for producing microporous organic membranes face challenges in achieving high chemical and thermal stability with minimal defects, leading to thicker membranes that decrease permeance for target molecules.

Innovation Solution

A process involving a sacrificial layer with identical functional groups, sequential application of organic compounds with complementary functional groups, and subsequent dissolution of the sacrificial layer to produce free-standing microporous organic membranes with controlled thickness and porosity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the layer-by-layer process is used to produce microporous organic membranes, then high chemical and thermal stability is achieved, but the membranes become thicker which decreases permeance for target molecules

Engineering Contradiction:
Improvechemical and thermal stabilityVSAvoidmembrane thickness
Core Design Contradiction:
ReliabilityVSLength of moving object

Solution Approach 1:

The patent applies preliminary action by using a sacrificial layer that is prepared in advance with specific functional groups. This sacrificial layer serves as a template that guides the subsequent deposition of organic compounds. The sacrificial layer is then selectively removed, leaving behind a porous structure with controlled thickness and high stability, resolving the contradiction between membrane thickness and stability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The sacrificial layer acts as an intermediary element in the membrane fabrication process. It mediates between the substrate and the final porous membrane structure, enabling controlled deposition of organic compounds while maintaining precise thickness control. The intermediary sacrificial layer is temporarily present during fabrication and then removed to create the final porous structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Manufacturing precision

If a large number of layers are applied to cover defects and pores in the substrate, then uniform coating is achieved, but the membrane thickness increases significantly decreasing permeance

Engineering Contradiction:
Improvecoating uniformityVSAvoidmembrane thickness
Core Design Contradiction:
Manufacturing precisionVSLength of moving object

Solution Approach 1:

The patent applies the taking out principle by selectively removing the sacrificial layer after it has served its templating function. This extraction of the sacrificial material creates void spaces that form the porous structure, allowing the membrane to achieve uniform coating without requiring multiple thick layers, thus maintaining both coating quality and permeance.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention utilizes porous materials principle by creating a membrane with controlled porosity through the sacrificial layer template. The porous structure allows molecules to pass through while maintaining mechanical integrity and uniform coating, eliminating the need for thick multilayer coatings that would reduce permeance.

Inventive Principle:
Principle #31Porous materials

3Ease of manufacture

If powder materials are used directly from solvothermal or hydrothermal processes, then production is simplified, but the materials require coating of substrates which adds complexity

Engineering Contradiction:
Improveproduction simplicityVSAvoidsubstrate coating process
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the membrane fabrication into distinct functional layers: a sacrificial template layer and organic compound layers. This segmentation allows each layer to be optimized independently - the sacrificial layer simplifies production while the organic layers provide the final membrane functionality, reducing overall process complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The sacrificial layer is prepared in advance as a preliminary structure that simplifies the subsequent membrane formation process. By pre-establishing the template architecture, the method avoids complex substrate coating procedures and enables direct deposition of organic compounds to form the final membrane structure.

Inventive Principle:
Principle #10Preliminary action

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 method enables the production of thin, defect-free, highly stable microporous organic membranes with defined thickness and porosity, suitable for various applications including gas separation and chemical sensing.

Implementation Method 1

at least one of the functional groups of a layer or the sacrificial layer reacts with at least one of the functional groups of the subsequent layer

Methodology Applied
Scientific EffectChemical bonding: Chemical Bonding

Implementation Method 2

dissolving the sacrificial layer

Methodology Applied
Scientific EffectDissolution: Solvation

Implementation Method 3

the functional groups of the successive layers are complementary and/or protected by protective groups

Methodology Applied
Scientific EffectCovalent bonding: Chemical Bonding

Data Source

PatentEP2992947B1Method for the preparation of microporous organic membranes, microporous organic membranes and use of same
Publication Date: 2023.03.01 KARLSRUHER INST FUR TECH
  • EP2992947B1 patent drawingFigure 1
  • EP2992947B1 patent drawingFigure 2
  • EP2992947B1 patent drawingFigure 3

AI summary

The invention relates to a method for producing microporous organic membranes (POF), the microporous organic membranes produced by this method, and their use. The microporous organic membranes, containing at least two different organic compounds with at least two or three functional groups, can be produced as follows: First, a sacrificial layer with a plurality of identical functional groups is provided, onto which a first layer of the first organic compound is applied. A first layer of the second organic compound is then applied to this. By successively applying further layers, a POF membrane of the desired thickness is produced. Finally, the sacrificial layer is dissolved and the POF membrane is removed.