Nanoparticle Synthesis via Cold Plasma Droplet Injection
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Solution Overview
Problem
Existing methods for producing metal nanoscale materials, such as nanoparticles, are complex, costly, and environmentally harmful, with chemical synthesis requiring harsh chemicals, high temperatures, and skilled labor, and existing plasma-based methods produce large nanoparticles that are difficult to deliver effectively to point of use.
Innovation Solution
A method using cold non-thermal equilibrium plasma to produce metal nanoscale materials within liquid droplets, where droplets are injected into a plasma region for rapid conversion, allowing for direct delivery to the point of use without intermediate collection, using a nebuliser or piezoelectric droplet generator, and an apparatus with a plasma container, droplet generator, and interface manifold to control droplet flow and plasma generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If chemical synthesis methods are used to produce nanoparticles, then nanoparticles can be formed with controlled surface characteristics, but the process becomes complex, costly, and environmentally harmful requiring harsh chemicals and skilled labor
Solution Approach 1:
The patent replaces chemical synthesis methods with a physical plasma-based method. Instead of using chemical reducing agents and complex multi-step chemical reactions, the invention uses plasma irradiation to directly convert precursor molecules in liquid droplets into nanoparticles. This substitution eliminates the need for harsh chemicals, skilled labor, and complex process control while maintaining nanoparticle quality and surface characteristics.
Solution Approach 2:
The patent changes the fundamental parameters of the synthesis process by using plasma temperature and energy distribution instead of chemical concentration and pH control. By adjusting plasma power, gas flow rate, and droplet exposure time, the method achieves precise control over nanoparticle formation without requiring complex chemical reagent systems or skilled operational intervention.
2Productivity
If very high temperature plasma is used to vaporise droplets and form nanoparticles, then nanoparticles can be produced rapidly, but large nanoparticles result and collection requires quenching gas and intermediate steps
Solution Approach 1:
The patent fundamentally changes the temperature parameter from very high temperature (1000°C) to low temperature (below 100°C) plasma. This parameter change allows rapid nanoparticle synthesis while maintaining small, controlled nanoparticle sizes and eliminating the need for quenching gas and intermediate collection steps. The nanoparticles can be directly delivered to the point of use within the gaseous stream.
3Speed
If thermal equilibrium plasma at high temperature is used, then precursor vaporisation and nanoparticle formation occur rapidly, but the nanoparticles produced are large and require intermediate collection
Solution Approach 1:
The patent changes the plasma state from thermal equilibrium to non-thermal equilibrium, and from high temperature to low temperature. In non-thermal equilibrium plasma, electrons have high energy for rapid reactions while the bulk gas remains cold, preventing nanoparticle growth. This parameter change enables fast reaction speeds with small nanoparticle sizes and direct delivery capability.
Solution Approach 2:
The patent uses a composite approach combining liquid droplet precursor delivery with non-thermal plasma treatment. The liquid carrier evaporates completely while the metal salt precursors are converted to nanoparticles, creating a composite process that achieves both rapid formation and small size control without intermediate collection.
4Reliability
If droplets are exposed to plasma for extended periods to ensure complete conversion, then precursor conversion is thorough, but the process time increases and productivity decreases
Solution Approach 1:
The patent uses pulsed plasma irradiation instead of continuous exposure. The plasma is applied in short, intense pulses that provide sufficient energy for complete precursor conversion within milliseconds. This periodic action maintains high conversion reliability while maximizing productivity by minimizing total exposure time and enabling rapid batch processing.
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 enables the rapid production of high-quality nanoparticles with narrow size distribution and high synthesis rates, eliminating the need for harsh chemicals and skilled labor, and allows for immediate delivery to the point of use, enhancing nanoparticle functionality and reducing environmental impact.
Implementation Method 1
droplets are injected into a plasma region for rapid conversion
Implementation Method 2
A method using cold non-thermal equilibrium plasma to produce metal nanoscale materials within liquid droplets
Implementation Method 3
vaporising the droplets to release the precursor at supersaturation level
Implementation Method 4
leading to condensation and formation of nanoparticles
Data Source
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AI summary
A method of producing nanoscale materials comprising the steps of entraining liquid droplets containing at least one nanoparticle precursor within a gaseous stream, and passing said gaseous stream containing said liquid droplets through a non-thermal equilibrium plasma whereby said plasma interacts with said at least onenanoparticle precursor to produce nanoparticles within said droplets without substantial evaporation of the droplets and conveying the thus produced nanoparticles within said gaseous stream downstream of said plasma.