Smooth Surface Coating for Liquid and Viscoelastic Repellency

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Solution Overview

Problem

Current surfaces, such as superhydrophobic and slippery liquid-infused porous surfaces, are ineffective in repelling both liquids and viscoelastic solids like feces or mud, and are prone to bacterial adhesion, which is a challenge for water-saving and easy-to-clean applications.

Innovation Solution

A smooth surface coating comprising a chemical layer and a lubricant, where the chemical layer is formed using a polymerizable silane or siloxane and a solvent with a catalyst, and the lubricant is a perfluorinated or silicone oil, creating a stable repellant surface that minimizes adhesion to viscoelastic materials without altering the surface roughness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If superhydrophobic surfaces are used to repel liquids, then water repellency is improved, but bacterial adhesion increases and viscoelastic solid repellency is lost

Engineering Contradiction:
Improveliquid repellencyVSAvoidbacterial adhesion
Core Design Contradiction:
Object-affected harmful factorsVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a lubricant layer as an intermediary between the solid substrate and external contaminants. This lubricant layer, composed of liquid crystals or other suitable lubricants, creates a slippery interface that repels both liquids and viscoelastic solids while preventing bacterial adhesion. The lubricant acts as a mediator that transfers the repellant properties without the drawbacks of superhydrophobic surfaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention combines multiple materials and functional layers to create a composite coating system. This includes the base substrate, a chemical layer for surface modification, and a lubricant layer for repellant functionality. The composite structure integrates the advantages of different materials while eliminating their individual disadvantages, achieving broad-spectrum repellency.

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If surface roughening is applied to create superhydrophobic properties, then water repellency is improved, but adhesion to viscoelastic solids increases

Engineering Contradiction:
Improvewater repellencyVSAvoidadhesion force
Core Design Contradiction:
Object-affected harmful factorsVSForce

Solution Approach 1:

The patent changes the surface energy parameters by applying a chemical layer and lubricant coating, transforming the surface from high-energy (sticky) to low-energy (slippery). This parameter change in surface chemistry, rather than physical roughness, achieves water repellency while maintaining low adhesion to viscoelastic solids.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The lubricant layer serves as an intermediary that provides a low-friction interface between the substrate and viscoelastic solids. This intermediary layer prevents direct contact and strong adhesion between the solid substrate and sticky materials like feces or mud, while still allowing water repellency through the combined effect of the chemical layer and lubricant.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Ease of operation

If repeated flushing is performed to remove contaminants, then cleaning effectiveness is improved, but water consumption increases

Engineering Contradiction:
Improvecleaning effectivenessVSAvoidwater consumption
Core Design Contradiction:
Ease of operationVSLoss of substance

Solution Approach 1:

The lubricant-coated surface provides self-cleaning properties by preventing contaminant adhesion in the first place. The slippery surface causes contaminants to slide off easily with minimal water, and the surface can be renewed by simply reapplying lubricant, reducing the need for extensive flushing and water consumption.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The coating is applied in advance to prevent contaminant adhesion before it occurs. By pre-establishing the slippery lubricant layer, the surface proactively resists fouling, eliminating the need for reactive cleaning with large amounts of water and reducing overall water consumption.

Inventive Principle:
Principle #10Preliminary action

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 repels both liquids and viscoelastic solids, reducing water consumption for cleaning, preventing bacterial adhesion, and maintaining functionality even after repeated flushing or exposure to viscoelastic materials.

Implementation Method 1

a polymerizable silane or siloxane and a solvent with a catalyst

Methodology Applied
Scientific EffectPolymerization: Photopolymerisation

Implementation Method 2

a lubricant thereon... creating a stable repellant surface that minimizes adhesion to viscoelastic materials

Methodology Applied
Scientific EffectLubrication: Lubrication

Implementation Method 3

preventing bacterial adhesion

Methodology Applied
Scientific EffectAnti-fouling:

Data Source

PatentEP3988293B1Liquid and viscoelastic material repellent and Anti-biofouling coatings
Publication Date: 2024.08.14 THE PENN STATE RES FOUND INC
  • EP3988293B1 patent drawingFigure 1a~2
  • EP3988293B1 patent drawingFigure 3a~4b
  • EP3988293B1 patent drawingFigure 5a~6

AI summary

A coated smooth surface of a substrate repels liquids and viscoelastic materials and can have anti-staining and anti-biofouling properties. The smooth surface can be coated by applying a chemical layer on the surface and a lubricant. Such coated surfaces are useful for use in toilets, urinals, or other devices for the processing of liquids and viscoelastic materials such as solid or semi-solid metabolic waste of human digestive system. Such coated surfaces can also be applied to windows for buildings or vehicles such as automobiles or camera lenses to repel liquids (e.g., rain), ice, frost, insect residues, and birds' feces.