Conductive Polymer Films via Post-Deposition Side Chain Cleavage

Solution Overview

Problem

Conjugated polymers with long and/or branched side chains for solubility compromise electrical conductivity due to reduced π-π intermolecular interactions and active material fraction, while insoluble polymers lack processability.

Innovation Solution

Formation of insoluble conductive polymers through post-processing side chain removal, such as ester hydrolysis, to enhance electrical conductivity by increasing charge carrier density and reducing carrier localization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If long and/or branched side chains are added to solubilize the polymer backbone, then processability is improved, but electrical conductivity deteriorates due to reduced π-π intermolecular interactions and active material fraction

Engineering Contradiction:

ImproveprocessabilityVSAvoidelectrical conductivity

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The polymer structure is segmented into two functional parts: a conductive backbone and removable side chains. The side chains serve as temporary solubilizing agents during processing, then are removed post-deposition to restore high conductivity. This segmentation allows the material to have both solution processability and high electrical conductivity in the final device.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The side chains are attached preliminarily to enable solution processing and film formation. After the film is deposited, the side chains are removed through hydrolysis or other degradation methods. This preliminary action of adding solubilizing groups, then removing them after processing, resolves the contradiction between needing them for manufacturing and avoiding them for performance.

Inventive Principle:

Principle #10Preliminary action

2Reliability

If side chains are removed to increase electrical conductivity, then charge carrier density increases, but processability deteriorates due to insolubility

Engineering Contradiction:

Improveelectrical conductivityVSAvoidprocessability

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The side chains are attached preliminarily to enable solution processing and film formation. After the film is deposited, the side chains are removed through hydrolysis or other degradation methods. This preliminary action of adding solubilizing groups, then removing them after processing, resolves the contradiction between needing them for manufacturing and avoiding them for performance.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Different parts of the polymer have different functions at different stages: the side chains provide solubility during processing but are removed in the final product. The backbone maintains conductive properties throughout. This local quality differentiation in time and function allows both processability and high conductivity.

Inventive Principle:

Principle #3Local quality

3Ease of manufacture

If side chains are kept to maintain solubility, then processability is maintained, but active material fraction decreases due to reduced conductivity

Engineering Contradiction:

ImproveprocessabilityVSAvoidactive material fraction

Core Design Contradiction:

Ease of manufactureVSQuantity of substance

Solution Approach 1:

The polymer structure is segmented into two functional parts: a conductive backbone and removable side chains. The side chains serve as temporary solubilizing agents during processing, then are removed post-deposition to restore high conductivity. This segmentation allows the material to have both solution processability and high electrical conductivity in the final device.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The side chains are discarded after serving their purpose of enabling solution processing. They are removed through hydrolysis or degradation, leaving behind the high-conductivity backbone. The discarded side chains can potentially be recovered or the process optimized to minimize waste, but the key point is that temporary solubilizing groups are discarded after fulfilling their manufacturing function.

Inventive Principle:

Principle #34Discarding and recovering

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

Improves electrical conductivity to 10-100,000 S/cm by densifying active material and maintaining processability, suitable for applications like transparent thin film electrodes and organic thermoelectric devices.

Implementation Method 1

Formation of insoluble conductive polymers through post-processing side chain removal, such as ester hydrolysis

Methodology Applied

Scientific EffectHydrolysis: Hydrolysis

Data Source

PatentUS20250277083A1Conductive polymer materials and methods of making the same

Publication Date: 2025.09.04 GEORGIA TECH RES CORP

AI summary

Disclosed herein are methods of making a conductive polymer material, the method comprising: casting, on a substrate, a functionalized polymer solution comprising a conductive backbone of conjugated monomer units and a plurality of nonconductive side chains; and cleaving the plurality of nonconductive side chains off of the conductive backbone to form the conductive polymer material, the conductive polymer material being insoluble in at least one solvent, wherein the conductive backbone in the conductive polymer material comprises conjugated monomer units substituted with a hydroxymethyl substituent. Also disclosed herein are conductive polymer materials made by the same and conductive films comprising the same.