Sol-Gel Silica Glass Particles with Dispersed Semiconductor Nanoparticles
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Solution Overview
Problem
Current methods for preparing silica glass fine particles with dispersed semiconductor nanoparticles face challenges in maintaining high photoluminescence efficiency and durability, especially when applied in biotechnology where low concentrations and high salt conditions lead to nanoparticle degradation.
Innovation Solution
A sol-gel method is developed using a three-step process involving the use of metal alkoxides to coat and assemble Cd- and Se-containing semiconductor nanoparticles, resulting in silica glass fine particles with 10 or more nanoparticles per particle, achieving a particle size of 20 to 100 nm and maintaining high PL efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If semiconductor nanoparticles are dispersed in aqueous solution to maintain high PL efficiency, then photoluminescence efficiency is improved, but nanoparticles gradually agglomerate due to large specific surface area, causing PL efficiency to decrease
Solution Approach 1:
The patent uses metal alkoxides as intermediary substances that coat the nanoparticle surfaces and facilitate their assembly into stable superstructures. The alkoxides act as mediators between the hydrophilic nanoparticles and the aqueous environment, preventing agglomeration while maintaining high PL efficiency through controlled assembly processes.
Solution Approach 2:
The patent creates a nested structure where semiconductor nanoparticles are assembled into larger superstructures with controlled architectures. The nanoparticles are nested within silica glass matrices or organized in hierarchical arrangements, allowing them to maintain individual optical properties while achieving stable dispersion in aqueous environments.
2Illumination intensity
If semiconductor nanoparticles are synthesized in organic solution to achieve high brightness, then photoluminescence intensity is improved, but water removal at high levels is required, complicating the synthesis process
Solution Approach 1:
The patent changes the synthesis parameters by performing reactions in aqueous or alcoholic solutions instead of requiring complete water removal from organic solutions. This parameter change simplifies the synthesis process while maintaining high fluorescence brightness through controlled nanoparticle assembly and silica glass matrix formation.
Solution Approach 2:
The patent utilizes phase transition processes where metal alkoxides undergo hydrolysis and condensation to form silica glass matrices that encapsulate the nanoparticles. This phase transition from molecular alkoxides to condensed silica networks provides a straightforward pathway to stable nanoparticle assemblies without requiring complex water removal steps.
3Reliability
If silica glass is formed in network structure to prevent nanoparticle degradation, then durability is improved, but preparation conditions require precise control of hydrolysis and condensation reactions
Solution Approach 1:
The patent optimizes reaction parameters including pH control, temperature, and metal alkoxide concentration to achieve controlled hydrolysis and condensation reactions. By carefully adjusting these parameters, the patent forms durable silica glass networks that protect nanoparticles while maintaining relatively simple preparation conditions through systematic parameter optimization.
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 highly durable silica glass fine particles with high PL efficiency, suitable for biotechnology applications, where the nanoparticles are less prone to degradation even at low concentrations and in high salt conditions, ensuring effective fluorescence and stability.
Implementation Method 1
The sol-gel method uses water, it is preferable to use hydrophilic nanoparticles from the viewpoint of preventing agglomeration and quenching
Implementation Method 2
vitrification progresses under mild conditions at or close to normal temperature and pressure
Implementation Method 3
semiconductor nanoparticles are excellent in color-rendering properties because these particles emit bright fluorescence of various wavelengths according to the particle size even when irradiated with ultraviolet light of the same wavelength
Implementation Method 4
moisture and oxygen cannot easily permeate through silica glass when silica glass is formed in a network structure, making it possible to prevent degradation of dispersed nanoparticles for a long period of time
Data Source
AI summary
An object of the present invention is to prepare a fine particle with high durability and high brightness, in which semiconductor nanoparticles are assembled. The present invention provides fluorescent fine particles comprising Cd- and Se-containing semiconductor nanoparticles dispersed in silicon-containing fine particles, wherein the average particle size of the silicon-containing fine particles is 20 to 100 nm, and the number of semiconductor nanoparticles dispersed in the silicon-containing fine particles is 10 or more.