Carbon Nanotube Array Growth via Gas-Phase Catalyst and Co-Catalyst
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Solution Overview
Problem
The gas-phase catalyst process for producing carbon nanotube arrays lacks productivity and spinning properties compared to the solid-phase catalyst process, and there is a need for a method to enhance the growth rate and spinning properties of CNT arrays specifically tailored for the gas-phase catalyst process.
Innovation Solution
A method involving a substrate with a silicon oxide surface exposed to a gas-phase catalyst and hydrocarbon-based material gas, with a gas-phase co-catalyst like acetone, and a halide of an iron family element, such as iron (II) chloride, under controlled flow rates and pressure conditions to enhance growth rate and spinning properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If gas-phase catalyst process is used to produce CNT array, then production simplicity is improved, but productivity deteriorates
Solution Approach 1:
The patent changes the physical state parameter of the catalyst from solid-phase to gas-phase, and introduces a co-catalyst system with specific flow rate ratios (5-150%) to enhance the growth rate while maintaining the simplicity of the gas-phase process
Solution Approach 2:
The patent introduces a gas-phase co-catalyst (such as iron chloride) as an intermediary substance that mediates between the hydrocarbon-based material gas and the catalyst, facilitating faster CNT growth while maintaining the gas-phase process advantage
2Ease of manufacture
If gas-phase catalyst process is used to produce CNT array, then production simplicity is improved, but spinning properties deteriorate
Solution Approach 1:
The patent adjusts the flow rate ratio of co-catalyst to material gas (5-150%) and total pressure (1×10^2 to 1×10^3 Pa) to optimize CNT structure for spinning applications while maintaining gas-phase process simplicity
Solution Approach 2:
The patent creates a composite catalytic system combining gas-phase catalyst and gas-phase co-catalyst, producing CNT arrays with enhanced structural properties suitable for spinning into entangled bodies while keeping the process simple
3Productivity
If co-catalyst flow rate is increased, then growth rate is improved, but manufacturing precision deteriorates
Solution Approach 1:
The patent defines a broad optimal range for co-catalyst flow rate ratio (5-150%) and total pressure (1×10^2 to 1×10^3 Pa), providing flexibility in control while achieving high growth rates, thus reducing the impact of precision control difficulties
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
This method significantly improves the growth rate and spinning properties of CNT arrays, allowing for stable production of CNT entangled bodies with extended growth height ranges, enhancing mechanical, electrical, and thermal characteristics.
Implementation Method 1
a first step for allowing a substrate having a base surface being a surface formed of a silicon oxide-containing material, as at least part of a surface thereof, to exist in an atmosphere including a gas-phase catalyst; and a second step for allowing a hydrocarbon-based material gas and a gas-phase co-catalyst to exist in the atmosphere including the gas-phase catalyst to allow a plurality of carbon nanotubes to grow on the base surface of the substrate
Implementation Method 2
allowing a substrate having a base surface being a surface formed of a silicon oxide-containing material, as at least part of a surface thereof, to exist in an atmosphere including a gas-phase catalyst
Data Source
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AI summary
A method for producing a carbon nanotube array is provided as a means for enhancing productivity of a CNT array to be produced by a gas-phase catalyst process and a means for enhancing spinning properties of the CNT array, comprising: a first step for allowing a substrate having a base surface being a surface formed of a silicon oxide-containing material, as at least part of a surface thereof, to exist in an atmosphere including a gas-phase catalyst; and a second step for allowing a material gas and a gas-phase co-catalyst to exist in the atmosphere including the gas-phase catalyst to allow a plurality of carbon nanotubes to grow on the base surface of the substrate to obtain on the base surface the carbon nanotube array formed of the plurality of carbon nanotubes.