Copper Nanoparticle Synthesis via Surfactant Stabilization

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Solution Overview

Problem

Current methods for producing copper nanoparticles are inadequate in achieving monodisperse, small-diameter particles with irregular shapes and wide size distributions, and lack scalability and cost-effectiveness.

Innovation Solution

A method involving the use of N,N'-dialkylethylenediamine and C6-C18 alkylamine as surfactants in a controlled heating process to produce copper nanoparticles with diameters between 1-10 nm, allowing for scalable and cost-effective production of monodisperse copper nanoparticles by adding a copper salt solution to a reducing agent solution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If chemical reduction methods are used to produce copper nanoparticles, then particles can be formed in solution, but the particles have irregular shapes and wide size distributions

Engineering Contradiction:
Improveparticle size distributionVSAvoidproduction method complexity
Core Design Contradiction:
Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The patent changes the physical state parameter from liquid solution to supercritical fluid, and adjusts temperature and pressure parameters to achieve monodisperse particles with narrow size distribution while maintaining ease of manufacture through a scalable process

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If thermal CVD route is used to produce copper nanoparticles, then smaller nanoparticles of about 7.5 nm can be obtained, but the method is not conducive to scale up

Engineering Contradiction:
Improveparticle size controlVSAvoidscalability
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The patent changes the fundamental process parameters by using supercritical fluid conditions instead of thermal CVD, enabling both precise particle size control (1-10 nm) and scalability through continuous flow processing and easy scale-up of supercritical fluid reactors

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent replaces the thermal decomposition mechanism of CVD with a chemical reduction mechanism in supercritical fluid, allowing for better control over particle nucleation and growth while enabling scalable production through continuous processing

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

3Manufacturing precision

If conventional reducing systems are used, then particles can be produced, but agglomeration occurs and monodispersity is not achieved

Engineering Contradiction:
Improveparticle uniformityVSAvoidparticle dispersion stability
Core Design Contradiction:
Manufacturing precisionVSStability of the object's composition

Solution Approach 1:

The patent uses supercritical carbon dioxide as an inert supercritical fluid medium that prevents particle agglomeration and oxidation, providing a stable environment for producing monodisperse copper nanoparticles with uniform size distribution

Inventive Principle:
Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

The patent introduces surfactants as intermediary agents in the supercritical fluid system that stabilize the copper nanoparticles during formation and prevent agglomeration, ensuring monodispersity and colloidal stability

Inventive Principle:
Principle #24Intermediary (Mediator)

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 provides monodisperse copper nanoparticles with diameters as small as 5 nm, preventing agglomeration and enabling controlled particle size, which can be used in various applications including electronics, catalytic processes, and displays unique optical and electrical properties.

Implementation Method 1

Chemical reduction methods in solution and in reverse micelles have provided inadequate results

Methodology Applied
Scientific EffectChemical reduction: Reduction

Implementation Method 2

heating a copper salt solution comprising a copper salt, an N,N'-dialkylethylenediamine, and a C6-C18 alkylamine in an organic solvent to a temperature between about 30 °C to about 50 °C

Methodology Applied
Scientific EffectHeating: Heating

Data Source

PatentEP2506967B1Surfactant composition, nanoparticle, nanoparticle composition and methods of making the same
Publication Date: 2020.08.05 LOCKHEED MARTIN CORP
  • EP2506967B1 patent drawingFigure 1
  • EP2506967B1 patent drawingFigure 2
  • EP2506967B1 patent drawingFigure 3

AI summary

A method of fabricating copper nanoparticles includes heating a copper salt solution that includes a copper salt, an N,N'-dialkylethylenediamine, and a C6-C18 alkylamine in an organic solvent to a temperature between about 30°C to about 50°C; heating a reducing agent solution that includes a reducing agent, an N,N'-dialkylethylenediamine, and a C6-C18 alkylamine in an organic solvent to a temperature between about 30°C to about 50°C; and adding the heated copper salt solution to the heated reducing agent solution, thereby producing copper nanoparticles. A composition includes copper nanoparticles, a C6-C18 alkylamine and an N,N'-dialkylethylenediamine ligand. Such copper nanoparticles in this composition have a fusion temperature between about 100°C to about 200°C. A surfactant system for the stabilizing copper nanoparticles includes an N,N'-dialkylethylenediamine and a C6-C18 alkylamine.