Polymeric Micro-Nano Composite Surface for Oil-Water Separation

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Solution Overview

Problem

Current polymeric materials used for oil-water separation, such as cellulose films or fibers, lack durability and effective surface functionality for high-viscosity oil separation and water absorption, with existing surface treatment methods being limited in scalability and adhesion, and prone to aging due to thermodynamic instability.

Innovation Solution

A polymeric material with a micro-nano composite structure featuring concavo-convex grooves and nanoscale protrusions formed through atmospheric pressure plasma treatment, which enhances hydrophilicity and oil repellency without the need for vacuum equipment or masks, allowing for large-area, environmentally friendly manufacturing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Shape

If conventional polymeric materials (cellulose films or fibers) are used for oil-water separation, then the material is readily available and easy to manufacture, but the surface roughness at nanometer level is insufficient leading to poor hydrophilicity and oil repellency

Engineering Contradiction:
Improvesurface roughnessVSAvoidmanufacturing complexity
Core Design Contradiction:
ShapeVSEase of manufacture

Solution Approach 1:

The patent transitions from macro-scale surface treatment to micro-scale and nano-scale surface structuring by forming concavo-convex grooves (1-10 μm width) and nanoscale protrusions (50-500 nm height) on the polymer surface. This dimensional transformation creates the necessary surface roughness for superhydrophilicity and oleophobicity without requiring complex manufacturing processes

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent replaces conventional mechanical surface treatment methods (wet etching, UV treatment, plasma/ion treatment) with a chemical etching process using potassium permanganate solution. This substitution achieves the desired micro-nano structure through chemical reactions rather than mechanical or physical means, simplifying the manufacturing process while achieving the target surface morphology

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If surface treatment methods (wet etching, UV treatment, plasma treatment) are applied to improve hydrophilicity, then the surface functionality is enhanced, but the treatment process becomes complex and scalability is limited

Engineering Contradiction:
ImprovehydrophilicityVSAvoidprocess complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines multiple surface treatment objectives (creating micro-nano structure, achieving superhydrophilicity, and providing oleophobicity) into a single chemical etching process using potassium permanganate. This merging of functions into one process step eliminates the need for sequential treatments and simplifies the overall manufacturing complexity while achieving all desired surface properties

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent controls the etching process by adjusting parameters such as potassium permanganate concentration (0.1-10%), etching time (1-24 hours), and temperature (20-80°C) to precisely control the formation of micro-nano structures. By optimizing these parameters, the process achieves consistent superhydrophilic and oleophobic surface properties across large areas, enabling scalability

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If conventional surface treatment is applied, then initial hydrophilicity is improved, but the surface returns to hydrophobicity over time due to thermodynamic instability

Engineering Contradiction:
Improvesurface stabilityVSAvoiddurability of hydrophilicity
Core Design Contradiction:
Stability of the object's compositionVSDuration of action of stationary object

Solution Approach 1:

The patent creates a composite surface structure combining polymer base material with inorganic manganese dioxide deposits formed during chemical etching. This composite micro-nano structure, consisting of concavo-convex grooves filled with nanoscale protrusions, provides permanent superhydrophilic and oleophobic properties by combining the mechanical stability of the polymer with the surface energy properties of the inorganic deposits

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent performs preliminary chemical etching treatment that permanently modifies the polymer surface chemistry and morphology before the material is put into service. The potassium permanganate etching process creates stable micro-nano structures and surface functional groups that maintain superhydrophilicity and oleophobicity throughout the material's service life, preventing the aging effect that plagues conventional treatments

Inventive Principle:
Principle #10Preliminary action

4Adaptability or versatility

If high-viscosity oil separation is required, then specialized surface structuring is needed, but existing methods lack effectiveness for high-viscosity oils like bunker C oil or crude oil

Engineering Contradiction:
Improveoil viscosity rangeVSAvoidsurface structure precision
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent creates local variations in surface properties by forming concavo-convex grooves with specific dimensions (1-10 μm width, 1-10 μm depth) and nanoscale protrusions (50-500 nm height) that provide tailored wettability characteristics. This local structuring creates regions with enhanced capillary action and surface energy differentiation, enabling the surface to selectively interact with high-viscosity oils while maintaining water repellency

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent utilizes the curved, concavo-convex groove structures and nanoscale protrusions to create favorable contact angle geometries for oil droplets. The curved surfaces and varying radii of curvature in the micro-nano structure optimize the interaction between the surface and high-viscosity oil, enhancing oleophobicity through geometric control of wetting behavior

Inventive Principle:
Principle #14Spheroidality (Curvature)

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 treated polymeric material exhibits improved hydrophilicity and oleophobicity, enabling effective oil-water separation and purification, with enhanced durability and scalability, suitable for applications like oil spill cleanup and seawater desalination.

Implementation Method 1

A polymeric material with a micro-nano composite structure featuring concavo-convex grooves and nanoscale protrusions formed through atmospheric pressure plasma treatment

Methodology Applied
Scientific EffectPlasma treatment: Plasma

Data Source

PatentEP3722389A1Polymeric material having micro-nano composite structure, device including the same, and method for manufacturing the polymeric material
Publication Date: 2020.10.14 KOREA INST OF SCI & TECH
  • EP3722389A1 patent drawingFigure 1
  • EP3722389A1 patent drawingFigure 2
  • EP3722389A1 patent drawingFigure 3

AI summary

Provided is a polymeric material having a micro-nano composite structure, a device including the same, and a method of manufacturing the polymeric material. The polymeric material includes a polymer fiber or film, wherein the polymer fiber or film has, on a surface thereof, a micro-nano composite structure including a microstructure containing concavo-convex grooves having a microscale semi-cylindrical shape (" ") and a nanopattern containing nanoscale protrusions formed on a surface of the microstructure. The polymeric material has excellent absorbency and hydrophilic or super-hydrophilic surface properties, and also has oleophobic or super-oleophilic properties in water, and thus may be effectively applied to fields such as oil-water separation, purification, and filters. The polymeric material may be readily manufactured through an environmentally friendly, large-area atmospheric pressure plasma process.