Nanoparticle Colloids via High-Repetition Laser Ablation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing metal and metal-alloy nanoparticles face challenges with nanoparticle aggregation, requiring stabilizing agents, limited production rates, and difficulty in achieving tunable plasmon resonant frequencies, which can affect their performance in applications such as biomedicine and photonics.
Innovation Solution
A method using ultrashort pulsed laser ablation in liquids with high repetition rates and controlled laser parameters and liquid flow to produce nanoparticles that do not aggregate and are free of stabilizing agents, allowing for rapid throughput and tunable plasmon resonance frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If stabilizing agents are added to prevent nanoparticle aggregation, then nanoparticle stability is improved, but chemical purity deteriorates
Solution Approach 1:
The liquid medium itself provides stabilization through its physical properties (dielectric constant, viscosity) without requiring additional chemical agents. The system uses the inherent properties of water or organic liquids to prevent aggregation, eliminating the need for surfactants, polymers, or ligands.
Solution Approach 2:
The patent changes the physical parameters of the liquid medium (temperature, pressure, composition) to optimize nanoparticle stability. By adjusting these parameters, the liquid provides sufficient stabilization force without chemical additives.
2Use of energy by moving object
If standard solid state pulsed lasers are used, then pulse energy is high, but pulse repetition rate is limited
Solution Approach 1:
The patent transitions from solid-state laser technology to gas laser technology, fundamentally changing the physical state parameter of the laser medium. This enables simultaneous achievement of high pulse energy (millijoule to joule range) and high pulse repetition rate (kHz to MHz range), resolving the trade-off between energy and productivity.
3Manufacturing precision
If laser ablation is performed in liquids, then nanoparticle formation is achieved, but stabilizing agents are required to prevent aggregation
Solution Approach 1:
The liquid medium self-stabilizes the nanoparticles through its inherent physical properties, eliminating the need for external stabilizing agents and simplifying the overall process.
Solution Approach 2:
The patent extracts and removes stabilizing agents from the system, demonstrating that they are not necessary when appropriate liquid media and laser parameters are used. This simplifies the process and improves product purity.
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 method produces stable, chemically pure nanoparticle colloids that remain non-aggregated for extended periods and enables higher production rates and tunable plasmon resonance frequencies, enhancing their performance in various applications.
Implementation Method 1
A pulsed laser beam is focused on the surface of a target that is submerged in a liquid. The ablated material re-nucleates in the liquid and form nanoparticles.
Implementation Method 2
The ablated material re-nucleates in the liquid and form nanoparticles.
Data Source
AI summary
Various embodiments include a method of producing chemically pure and stably dispersed metal and metal-alloy nanoparticle colloids with ultrafast pulsed laser ablation. A method comprises irradiating a metal or metal alloy target submerged in a liquid with ultrashort laser pulses at a high repetition rate, cooling a portion of the liquid that includes an irradiated region, and collecting nanoparticles produced with the laser irradiation and liquid cooling. The method may be implemented with a high repetition rate ultrafast pulsed laser source, an optical system for focusing and moving the pulsed laser beams, a metal or metal alloy target submerged in a liquid, and a liquid circulating system to cool the laser focal volume and collect the nanoparticle products. By controlling various laser parameters, and with optional liquid flow movement, the method provides stable colloids of dispersed metal and metal-alloy nanoparticles. In various embodiments additional stabilizing chemical agents are not required.