Self-Similar Structural Coatings for Anti-Icing and Dewetting

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Solution Overview

Problem

Current anti-icing coatings are not durable, abrasion-resistant, and effective in high humidity conditions, as they fail to simultaneously repel water and inhibit ice formation over extended periods, especially in applications like aircraft and automotive surfaces.

Innovation Solution

A structural coating with a continuous matrix and discrete templates that create porosity and surface roughness, combined with nanoparticles to inhibit ice nucleation, providing a self-similar structure that maintains anti-wetting and anti-icing properties even after abrasion, using a combination of materials like polyurethanes and calcium carbonate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If superhydrophobic surfaces are used to repel water, then water contact angle increases, but ice adhesion increases due to large surface area in high humidity conditions

Engineering Contradiction:
Improvecontact angleVSAvoidice adhesion
Core Design Contradiction:
ShapeVSObject-affected harmful factors

Solution Approach 1:

The patent applies porous materials by incorporating discrete templates that create a porous structure within the coating matrix. This porous structure reduces the effective surface area available for ice adhesion while maintaining water repellency through controlled porosity rather than extreme surface roughness, thereby resolving the contradiction between high contact angle and low ice adhesion.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent uses composite materials by combining the continuous coating matrix with discrete templates and nanoparticles to create a multi-component system. This composite structure allows simultaneous optimization of water repellency and ice phobicity through the synergistic interaction of different materials, addressing the contradiction between hydrophobicity and ice adhesion resistance.

Inventive Principle:
Principle #40Composite materials

2Shape

If lithographic techniques are used to create surface features, then contact angle increases, but manufacturing complexity and cost increase

Engineering Contradiction:
Improvesurface featuresVSAvoidscalability
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent applies parameter changes by transitioning from lithographic fabrication to a coating process where surface features are created through controlled evaporation and self-assembly during application. This changes the manufacturing parameters from precision lithography to spray or dip coating conditions, enabling scalable production while maintaining effective surface features for water repellency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs self-service by utilizing the self-assembly behavior of discrete templates and nanoparticles during the coating drying process. The surface features form automatically through evaporation-driven self-organization rather than requiring external lithographic patterning, greatly simplifying manufacturing and enabling scalable production.

Inventive Principle:
Principle #25Self-service

3Reliability

If single-layer nanoparticle coatings are used for melting-point depression, then anti-icing capability is achieved, but abrasion resistance decreases

Engineering Contradiction:
Improveanti-icing capabilityVSAvoidabrasion resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent uses composite materials by embedding nanoparticles within a continuous coating matrix along with discrete templates. This composite structure provides abrasion resistance from the matrix while maintaining anti-icing capability from the nanoparticles, resolving the contradiction between durability and functional performance.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies porous materials by creating a structured coating with discrete templates that form a robust framework. This porous yet structured architecture provides mechanical strength and abrasion resistance while accommodating nanoparticles for anti-icing functionality, overcoming the weakness of single-layer nanoparticle coatings.

Inventive Principle:
Principle #31Porous materials

4Duration of action of moving object

If coatings are designed for extended duration anti-icing, then ice formation delay increases, but coating complexity increases

Engineering Contradiction:
Improveanti-icing durationVSAvoidcoating structure
Core Design Contradiction:
Duration of action of moving objectVSDevice complexity

Solution Approach 1:

The patent employs composite materials with a specific architecture combining continuous matrix, discrete templates, and nanoparticles. This composite structure achieves extended anti-icing duration through the synergistic effects of melting-point depression and dewetting, while the modular nature of the composite allows for scalable manufacturing that mitigates complexity issues.

Inventive Principle:
Principle #40Composite materials

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 coating effectively delays ice formation and reduces ice adhesion, maintaining functionality over extended periods and withstanding environmental impacts, while being scalable and cost-effective for large-area application.

Implementation Method 1

discrete templates dispersed within the matrix that create porosity and surface roughness

Methodology Applied
Scientific EffectPorosity: Porosity

Implementation Method 2

plurality of nanoparticles within the matrix that inhibit ice nucleation

Methodology Applied
Scientific EffectMelting-point depression:

Implementation Method 3

maintaining anti-wetting and anti-icing properties

Methodology Applied
Scientific EffectHydrophobicity: Hydrophobe

Data Source

PatentEP2928970B1Structural coatings with dewetting and Anti-icing properties, and coating precursors for fabricating same
Publication Date: 2022.10.19 HRL LAB
  • EP2928970B1 patent drawingFigure 1
  • EP2928970B1 patent drawingFigure 2A
  • EP2928970B1 patent drawingFigure 2B

AI summary

Variations of this invention provide durable, impact-resistant structural coatings that have both dewetting and anti-icing properties. The coatings in some embodiments possess a self-similar structure that combines a low-cost matrix with two feature sizes that are tuned to affect the wetting of water and freezing of water on the surface. Dewetting and anti-icing performance is simultaneously achieved in a structural coating comprising multiple layers, wherein each layer includes a continuous matrix; discrete templates dispersed that promote surface roughness to inhibit wetting of water; and nanoparticles that inhibit heterogeneous nucleation of water. These structural coatings utilize low-cost, lightweight, and environmentally benign materials that can be rapidly sprayed over large areas using convenient coating processes. The presence of multiple layers means that if the surface is damaged during use, freshly exposed surface will expose a coating identical to that which was removed, for extended lifetime.