Vermiculite Ionic Channels via Partial Thermal Expansion

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Solution Overview

Problem

Existing salinity difference power generation systems face challenges in introducing ion transport channels with asymmetric structures that ensure structural stability, mass production feasibility, and continuous channel connectivity.

Innovation Solution

A method involving partial thermal expansion of a laminated film with restacked vermiculite to create an asymmetric ionic transport channel, which includes a third region with an expandable interlayer and a fourth region with a smaller interlayer thickness, allowing for controlled ion conduction and power generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If chemical etching is used to fabricate asymmetric ion transport channels, then channel asymmetry is achieved, but the fabrication process becomes complicated and expensive

Engineering Contradiction:
Improveasymmetric channel structureVSAvoidfabrication complexity and cost
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The invention changes the fabrication parameter from chemical etching to thermal expansion treatment. By controlling temperature parameters during thermal expansion, asymmetric channel structures are formed naturally without complex chemical processes, thereby reducing fabrication complexity and cost while maintaining channel asymmetry

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention utilizes the phase transition of water contained within the vermiculite layers during thermal expansion. When heated, the water expands and causes the vermiculite layers to separate and form asymmetric channels, providing a simple physical method to achieve channel asymmetry without chemical etching

Inventive Principle:
Principle #36Phase transitions

2Shape

If porous polymer-based membranes with different pore sizes are bonded, then channel asymmetry is achieved, but resistance increases due to discontinuous channel connection

Engineering Contradiction:
Improveasymmetric channel structureVSAvoidchannel continuity
Core Design Contradiction:
ShapeVSReliability

Solution Approach 1:

The invention merges multiple vermiculite layers into a single integrated laminated structure through thermal expansion. This creates continuous asymmetric channels that span across the entire membrane thickness, eliminating the discontinuities that occur when bonding separate porous polymer membranes together

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The invention uses vermiculite, a natural layered silicate mineral, as the base material for the membrane. The unique properties of vermiculite allow it to form continuous channels when thermally expanded, providing both structural integrity and channel continuity that composite bonding of porous polymers cannot achieve

Inventive Principle:
Principle #40Composite materials

3Shape

If thermal expansion is applied to vermiculite-based laminated film, then asymmetric channel structure is formed, but interlayer thickness varies across different regions

Engineering Contradiction:
Improveasymmetric channel structureVSAvoidinterlayer thickness uniformity
Core Design Contradiction:
ShapeVSManufacturing precision

Solution Approach 1:

The invention intentionally creates local variations in interlayer thickness by applying thermal expansion to specific regions of the vermiculite laminated film. Different regions are subjected to different thermal treatment conditions, resulting in asymmetric channel structures with controlled thickness variations that enable directional ion transport

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The vermiculite laminated film is divided into different regions with distinct thermal expansion characteristics. By segmenting the thermal treatment process, the invention creates controlled asymmetry in different parts of the membrane, allowing optimization of ion transport properties in each region

Inventive Principle:
Principle #1Segmentation

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 enables stable and efficient electric energy production using abundant low-cost resources, with the asymmetric structure reducing reverse ion conduction and enhancing power generation capabilities.

Implementation Method 1

a third region (R3) connected to the second region (R2) and having an interlayer with an interlayer thickness, the interlayer being expandable in thickness direction by heat

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

a device for producing power by conduction of alkali ions through an ion transport channel having an asymmetric structure

Methodology Applied
Scientific EffectIon conduction: Conduction (electrical)

Data Source

PatentEP4187088B1Ionic diode manufacturing method using partial thermal expansion of vermiculite-based laminated film and salinity difference power generating system using the same
Publication Date: 2025.06.04 IND ACADEMIC COOP FOUND YONSEI UNIV
  • EP4187088B1 patent drawingFigure 1~2
  • EP4187088B1 patent drawingFigure 3
  • EP4187088B1 patent drawingFigure 4

AI summary

Salinity (NaCI) difference energy generating system and method of manufacturing a structural asymmetric ionic transport channel by inducing partial thermal expansion of a laminated film in which vermiculite is re-stacked. Energy generating system capable of producing power by abundant low-cost resources based on the method. The energy power generating device is capable of generating power with an easy capacity control and abundant low-cost resources, and the energy power generating device satisfies size characteristics, structural stability characteristics, and furthermore, filtering characteristics may stably produce electrical energy using a solution having a concentration similar to that of seawater and river water.