Metal Microparticle Crystallite Control via Sulfate Ion Molar Ratio
Solution Overview
Problem
Current methods for producing metal microparticles, such as nickel, silver, and copper, face challenges in controlling the crystallite diameter relative to the particle diameter, leading to non-uniform physical properties and increased energy costs, especially in the liquid phase method.
Innovation Solution
The method involves using a thin film fluid formed between rotating processing surfaces, where a metal compound and a reducing agent are mixed with sulfate ions to control the molar ratio of sulfate ions to metal, allowing for precise control of the crystallite diameter to particle diameter ratio, thereby producing microparticles with desired physical properties at lower costs and energy consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional liquid phase methods are used to produce metal microparticles, then production cost is reduced, but control over crystallite diameter relative to particle diameter becomes difficult
Solution Approach 1:
The invention changes the chemical composition parameters of the liquid phase system by introducing sulfate ions and controlling the molar ratio of sulfate ions to metal ions. This parameter change enables precise control of crystallite diameter while maintaining the advantages of liquid phase production, resolving the contradiction between ease of manufacture and manufacturing precision.
2Manufacturing precision
If gas phase methods are used to produce metal microparticles, then crystallite diameter can be controlled, but energy consumption increases
Solution Approach 1:
The invention replaces the high-energy gas phase mechanical vaporization process with a low-energy liquid phase chemical reduction process. By using sulfate ion-controlled crystallization in liquid phase, the same level of crystallite diameter control is achieved without the high energy consumption of gas phase methods.
3Device complexity
If conventional methods are used without sulfate ion control, then production process is simpler, but physical property uniformity decreases
Solution Approach 1:
The invention introduces sulfate ions as a mediating substance that controls the crystallization process. The sulfate ions act as intermediaries between the metal ions and the reducing agent, enabling uniform crystallite formation and improving physical property uniformity while adding only moderate complexity to the production process.
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 continuous production of metal microparticles with controlled crystallite diameters, reducing energy costs and improving the uniformity of physical properties, while maintaining stability against shrinkage during heat treatment.
Implementation Method 1
a reducing reaction is carried out by controlling the reaction temperature and time
Implementation Method 2
The fluids to be processed which are introduced thereinto form a thin film fluid between the at least two processing surfaces
Data Source
Figure 1
Figure 2(A)~2(B)
Figure 3(A)~3(B)
AI summary
Provided is a method for producing metal microparticles in which the ratio of crystallite diameter to the particle diameter of the metal microparticles is controlled. At least two types of fluid to be processed are used, including a metal fluid in which a metal or a metal compound is dissolved in a solvent, and a reducing agent fluid which includes a reducing agent. Sulfate ions are included in one or both of the metal fluid and the reducing agent fluid. The fluid to be processed is mixed in a thin film fluid formed between at least two processing surfaces, at least one of which rotates relative to the other, and which are disposed facing each other and capable of approaching and separating from each other, and metal microparticles are precipitated. The present invention is characterized in that at this time, the ratio (d/D) of the crystallite diameter (d) of the metal microparticles to the particle diameter (D) of the metal microparticles is controlled by controlling the molar ratio of metal and sulfate ions in the mixed fluid to be processed.