Microflow Coating of Fine Composite Particles for Uniform Shell Control
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Solution Overview
Problem
Conventional methods for manufacturing fine composite particles lack precise control over reaction conditions, particularly temperature and duration, leading to uneven coating distribution and increased particle size distribution, which affects the quality and fluorescence spectrum of nano particles.
Innovation Solution
A method using a micro flow path to accurately control temperature, concentration, and retention time, allowing continuous production of fine composite particles with desired coating amounts, employing a reactor with a micro flow path of specified diameter and Reynolds number, and using multiple components for the core particles and coating layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional particle-manufacturing apparatuses are used to manufacture coated composite particles, then the manufacturing process can be carried out, but accurate control of temperature and duration in the reaction process cannot be achieved, leading to poor control of coating amount
Solution Approach 1:
The invention changes the physical parameters of the reaction system by using a micro flow path reactor, which enables precise control of temperature and duration parameters. The micro flow path geometry (1-5000 μm diameter) allows for controlled heat transfer and residence time, directly achieving accurate control of reaction conditions and coating amount
Solution Approach 2:
The invention uses fluid flow through micro channels to control the reaction process. By regulating the flow rate of reactants through the micro flow path, the duration of reaction is precisely controlled, and by controlling the flow conditions, temperature distribution is optimized, enabling reliable control of coating amount
2Manufacturing precision
If the reaction process is set longer than necessary to ensure accurate control of reaction condition, then the control accuracy is improved, but an excessively long reaction process causes an increase in particle size distribution due to Oswald maturation
Solution Approach 1:
The invention makes the reaction system dynamic by using continuous flow through micro channels. The flow rate can be adjusted to control residence time precisely, allowing the reaction to be completed in optimal time without excessive duration that would cause Oswald maturation and particle size distribution broadening
Solution Approach 2:
The micro flow path geometry changes the thermal and mass transfer parameters of the system, enabling accurate temperature control and precise residence time control. This allows the reaction to be optimized for both control accuracy and minimal particle size distribution increase
3Manufacturing precision
If the reaction time is extended to ensure accurate control, then the coating uniformity is improved, but the distribution in fluorescent spectrum increases due to increased particle size distribution
Solution Approach 1:
The continuous flow system allows dynamic control of residence time to achieve uniform coating without excessive reaction time. The flow conditions can be optimized to ensure uniform coating deposition while minimizing the time available for Oswald maturation that would broaden the fluorescent spectrum
Solution Approach 2:
The micro flow path geometry changes the heat and mass transfer parameters, enabling uniform temperature distribution that promotes uniform coating. Simultaneously, the residence time is precisely controlled to be sufficient for uniform coating but not so long as to cause significant particle size distribution and fluorescent spectrum broadening
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 approach enables the production of high-quality fine composite particles with even coating distribution, reduced particle size variation, and enhanced fluorescence strength, specifically achieving a half bandwidth increase of less than 15% and improved quantum yield.
Implementation Method 1
a micro flow path of 1-5000 μm in diameter and 1-4000 in Reynolds number is used for the reaction process
Implementation Method 2
mixing them and continuously supplying a resulting mixture into a micro flow path
Data Source
AI summary
In the present invention, the fine particle composite process is carried out with the step of reacting fine core particles and a raw material for coating layer by mixing them and continuously supplying a resulting mixture into a micro flow path. The micro flow path is specified to 1-4000 in Reynolds number. With this arrangement, the present invention ensures, in a technology using a reactor having a micro flow path, accurate control of reaction condition, uniformity of coating amount distribution, easy layer formation, and successive production of fine composite particles.