Heating Element Composition with Coated Nanosheet Fillers
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional sheet-shaped heating elements face challenges with non-uniform heating and poor efficiency due to geometric constraints and high percolation threshold values of conductive materials, requiring excessive material for desired electrical conductivity.
Innovation Solution
A composition for forming a heating element is developed, comprising a matrix particle, a composite filler with a nanosheet core coated by a polymer layer, and a solvent, maintaining a pH range of 5 to 9 to ensure stable dispersion and reduced conductivity loss over time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a high amount of conductive material is used to achieve required electrical conductivity, then electrical conductivity is improved, but material cost and processing complexity increase due to high percolation threshold
Solution Approach 1:
The patent uses composite filler particles comprising a conductive core (e.g., RuO2 nanosheets) coated with a polymer layer (e.g., polyacrylic acid). This composite structure allows the conductive core to provide electrical pathways while the polymer coating improves dispersibility and reduces aggregation, enabling lower percolation thresholds and reduced material quantities while maintaining required conductivity.
Solution Approach 2:
The patent controls the pH of the composition within a specific range (5-9) to optimize the ionization state of the polymer coating on filler particles. This pH control enhances the dispersibility and stability of the composite filler, preventing aggregation and maintaining effective conductivity with lower material content.
2Duration of action of stationary object
If conductive material is stored over time, then manufacturing time is flexible, but conductivity decreases due to aggregation and metal ion elution
Solution Approach 1:
The polymer coating layer on the conductive filler particles acts as an intermediary that prevents direct contact and aggregation between conductive cores. This coating layer maintains particle separation and stability during storage, preventing the aggregation that would otherwise lead to conductivity loss and metal ion elution over time.
Solution Approach 2:
The patent maintains the composition pH within the range of 5-9 to control the ionization and electrostatic repulsion characteristics of the polymer coating. This parameter control ensures long-term stability of the dispersion, preventing aggregation and conductivity degradation during storage.
3Stability of the object's composition
If nanosheet filler is dispersed in alkaline solution, then dispersibility is improved initially, but stability decreases due to aggregation after storage
Solution Approach 1:
The patent shifts from using strongly alkaline conditions (pH 12 or higher) to a controlled pH range of 5-9. This parameter change maintains sufficient dispersibility of the nanosheet filler while preventing the aggregation and metal ion elution that occur in highly alkaline environments during storage, thereby ensuring long-term stability and conductivity.
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 composition allows for the manufacture of heating elements with improved electrical conductivity and stability, maintaining 70% or more of initial conductivity after storage, and enhanced dispersibility of nanosheet fillers, reducing aggregation and metal ion elution, thus improving sinterability and heating characteristics.
Implementation Method 1
A heating element may have excellent thermal characteristics because it generates heat by using Joule heating based on a composite of a resistor and a conductor
Implementation Method 2
A heating element may have excellent thermal characteristics because it generates heat by using Joule heating based on a composite of a resistor and a conductor
Implementation Method 3
the composition has a pH in a range of about 5 to about 9
Data Source
AI summary
A composition for forming a heating element; a dried and sintered product thereof; and a method of preparing the composition for forming a heating element, the composition including a matrix particle, a composite filler, and a solvent, wherein the composite filler includes a core and a coating layer disposed on the core, the core includes a nanosheet filler, and the composition has a pH in a range of about 5 to about 9.