Functionalized Polythiophene Composition for Conductive Thermal-Stable Layers
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Solution Overview
Problem
Existing π-conjugated polymers used in solid electrolytes for capacitors suffer from low electrical conductivity and insufficient thermal stability, particularly in applications requiring high thermal resistance such as the automotive industry.
Innovation Solution
A process for producing a liquid composition of functionalized π-conjugated polythiophenes with specific pH adjustment and solvent conditions, followed by oxidative polymerization, to create a conductive polymer with enhanced thermal stability and conductivity, using solvents like water and bases to control molecular weight and particle size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If PEDOT/PSS dispersions are used as solid electrolytes, then the capacitors can be manufactured with conventional processes, but the electrical conductivity is limited and the particles are too large to penetrate smaller pores
Solution Approach 1:
The patent changes the chemical composition parameters by replacing PSS with sulfonate-functionalized polythiophene units, transforming the material from a composite dispersion to a self-doped polymer. This parameter change enables both high conductivity and small particle size simultaneously
Solution Approach 2:
The invention creates a composite structure within the polymer chain itself, where conductive polythiophene units are chemically bonded to sulfonate groups, forming an integrated self-doped system rather than a physical mixture of separate components
2Reliability
If functionalized polythiophenes are used to increase conductivity, then the electrical performance improves, but the thermal stability becomes insufficient for high-temperature applications
Solution Approach 1:
The patent modifies the chemical structure parameters by introducing specific functional groups (sulfonates) and controlling molecular weight distribution, creating a polymer architecture that maintains chain flexibility for conductivity while enhancing thermal resistance through increased molecular weight and crosslinking potential
3Length of moving object
If the particle size of PEDOT/PSS is reduced to penetrate smaller pores, then the electrode penetration improves, but the maximum solids content remains limited to about 3 wt.-%
Solution Approach 1:
The invention changes the fundamental parameter of particle formation by using a one-step polymerization process that produces ultra-fine particles (1-100 nm) directly in solution, eliminating the need for large PSS molecules and enabling high solids content up to 25 wt.-% in the liquid composition
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 resulting conductive polymer exhibits high thermal stability and conductivity, suitable for forming solid electrolyte layers in capacitors, improving their performance under thermal stress.
Implementation Method 1
oxidative polymerization of the thiophene monomers to obtain a liquid phase comprising a functionalized π-conjugated polythiophene
Data Source
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AI summary
The present invention relates to a process for producing a liquid composition comprising a functionalized π-conjugated polythiophenes, comprising the process steps of i) providing a liquid phase comprising a functionalized π-conjugated polythiophene that is dissolved or dispersed in a solvent, wherein the functionalized π-conjugated polythiophene comprises repeating units of the general formula (I) wherein X,Y are identical or different and are O, S, or NR1, wherein R1 is hydrogen or an aliphatic or aromatic residue having 1 to 18 carbon atoms; A is an organic residue carrying an anionic functional group; and wherein the liquid phase has a pH-value of less than 2.5; ii) adjusting the pH-value of the liquid phase provided in process step i) to a value in the range from 2.5 to 10 by the addition of a base. The present invention also relates to a liquid composition obtainable by this process, to a liquid composition comprising a functionalized π-conjugated polythiophene, wherein the composition, after is has been dried, is characterized by a certain weight loss at a given minimum temperature, to a process for the preparation of a layered body in which these liquid compositions are used for the formation of a conductive layer, to a layered body obtainable by this process and to the use of the liquid compositions for the preparation of a conductive layer in an electronic device.