Carburizing Prevention Layer for Aligned Carbon Nanotube Substrates

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Solution Overview

Problem

Conventional CVD methods for producing aligned carbon nanotubes face issues with catalyst deactivation due to carbonaceous impurities, leading to low growth efficiency and high costs, and metal substrates undergo deformation and carburization, affecting the quality and productivity of carbon nanotubes during repetitive use.

Innovation Solution

A substrate with a carburizing prevention layer formed on both surfaces of a metal base substrate, made from alloys like Fe-Cr, Fe-Ni, or Fe-Cr-Ni, is used to prevent deformation and catalyst deactivation, allowing for efficient production of high-quality aligned carbon nanotubes by maintaining substrate integrity and extending catalyst activity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a metal substrate is used for producing aligned carbon nanotubes by CVD method, then productivity and cost-effectiveness are improved, but the substrate undergoes deformation and carburization during repetitive use

Engineering Contradiction:
ImproveproductivityVSAvoidsubstrate integrity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent applies a composite structure consisting of a metal base substrate combined with a carburizing prevention layer. This composite material approach allows the substrate to maintain the high productivity and cost-effectiveness of metal while the protective layer prevents deformation and carburization during repetitive CVD usage, thereby resolving the contradiction between productivity and substrate integrity.

Inventive Principle:
Principle #40Composite materials

2Speed

If carbon nanotubes are produced in a high-concentrated carbon atmosphere, then growth rate is improved, but catalyst particles are deactivated by carbonaceous impurities

Engineering Contradiction:
Improvegrowth rateVSAvoidcatalyst activity
Core Design Contradiction:
SpeedVSReliability

Solution Approach 1:

The patent introduces an oxidizing agent as an intermediary substance that mediates between the high-concentrated carbon atmosphere and the catalyst particles. The oxidizing agent selectively removes carbonaceous impurities from the catalyst surface without significantly affecting the carbon nanotube growth rate, thus maintaining both high growth rate and catalyst activity.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the chemical composition parameters of the reaction atmosphere by adding an oxidizing agent to the high-concentrated carbon atmosphere. This parameter change allows the system to maintain high carbon concentration for fast growth while the oxidizing agent continuously cleanses the catalyst surface, preventing deactivation and maintaining reliable catalyst activity.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If a substrate is reused multiple times for carbon nanotube production, then cost-effectiveness is improved, but deformation accumulates affecting quality

Engineering Contradiction:
Improvecost-effectivenessVSAvoidquality
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies a carburizing prevention layer to the metal substrate before it is used for carbon nanotube production. This preliminary protective action prevents deformation and carburization from occurring during the first use, enabling the substrate to be reused multiple times without quality degradation, thus improving cost-effectiveness while maintaining manufacturing precision.

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 solution enables the production of high-quality aligned carbon nanotubes with improved growth rates and carbon efficiency, reducing substrate deformation and maintaining productivity over multiple uses, thus enhancing the cost-effectiveness and quality of carbon nanotube production.

Implementation Method 1

carburizing prevention layers formed on both surfaces of the metal base substrate

Methodology Applied
Scientific EffectCarburizing prevention: Diffusion Barrier

Implementation Method 2

producing, by means of chemical vapor deposition, the aligned carbon nanotube aggregates on the surface of the substrate

Methodology Applied
Scientific EffectChemical vapor deposition: Chemical Vapour Deposition

Data Source

PatentEP2397440B1Substrate for producing aligned carbon nanotube aggregates and method for producing the aligned carbon nanotube aggregates
Publication Date: 2019.11.20 ZEON CORP
  • EP2397440B1 patent drawingFigure 1
  • EP2397440B1 patent drawingFigure 2
  • EP2397440B1 patent drawingFigure 3

AI summary

A substrate of the present invention for producing aligned carbon nanotube aggregates on a surface thereof is a substrate for producing aligned carbon nanotube aggregates on a surface thereof, the substrate for producing aligned carbon nanotube aggregates including: a metal base substrate; and carburizing prevention layers formed on both front and back surfaces of the metal base substrate, respectively.