Quantum Dot Ligand Pre-Modification for Aqueous Compatibility
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Solution Overview
Problem
Current methods for making quantum dot nanoparticles aqueous compatible often result in materials with lower quantum yield and larger size, and can be detrimental to their physical and optical properties.
Innovation Solution
A method involving a quantum dot binding ligand with a solubilising group precursor, such as mercaptocarboxylic acid incorporating ethylene oxide units, is used to modify the nanoparticles before binding, avoiding post-binding modifications and ensuring appropriate stoichiometric addition of ligand modifying agents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If ligand exchange or interchelation procedures are used to render quantum dots aqueous compatible, then aqueous compatibility is improved, but quantum yield decreases and particle size increases
Solution Approach 1:
The ligand is pre-modified with the solubilising group precursor before binding to the quantum dot surface. This preliminary modification ensures that the ligand is ready to impart aqueous compatibility immediately upon binding, eliminating the need for post-binding modification steps that cause quantum yield loss and particle size increase.
Solution Approach 2:
The harmful post-binding modification step is extracted and eliminated from the process. By performing the solubilising group precursor modification before binding, the patent removes the source of quantum yield degradation and unwanted particle size increase that occur with conventional post-binding approaches.
2Adaptability or versatility
If ligand exchange procedures are used to render quantum dots aqueous compatible, then aqueous compatibility is improved, but particle size increases
Solution Approach 1:
The ligand is pre-modified with the solubilising group precursor before binding to the quantum dot surface. This preliminary modification ensures that the ligand is ready to impart aqueous compatibility immediately upon binding, eliminating the need for post-binding modification steps that cause quantum yield loss and particle size increase.
Solution Approach 2:
The harmful post-binding modification step is extracted and eliminated from the process. By performing the solubilising group precursor modification before binding, the patent removes the source of quantum yield degradation and unwanted particle size increase that occur with conventional post-binding approaches.
3Adaptability or versatility
If conventional ligand modification procedures are used, then aqueous compatibility is achieved, but physical and chemical stability deteriorates
Solution Approach 1:
The ligand is pre-modified with the solubilising group precursor before binding to the quantum dot surface. This preliminary modification ensures that the ligand is ready to impart aqueous compatibility immediately upon binding, eliminating the need for post-binding modification steps that cause quantum yield loss and particle size increase.
Solution Approach 2:
The harmful post-binding modification step is extracted and eliminated from the process. By performing the solubilising group precursor modification before binding, the patent removes the source of quantum yield degradation and unwanted particle size increase that occur with conventional post-binding approaches.
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 quantum dots that are stably dispersed in aqueous media, physically and chemically robust, with high quantum yield and smaller size, while maintaining or enhancing their fluorescence properties.
Implementation Method 1
converting the solubilising group precursor to a solubilising group
Implementation Method 2
The ligand compound chelates the surface of the quantum dot by donating lone pair electrons to the surface metal atoms
Implementation Method 3
Different sized quantum dots may be excited by irradiation with a single wavelength of light to give a discrete fluorescence emission of narrow band width as a consequence of quantum confinement effects
Implementation Method 4
The shell eliminates defects and dangling bonds from the surface of the core, which confines charge carriers within the core and away from surface states that may function as centres for non-radiative recombination
Data Source
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AI summary
The present invention relates to a method for producing aqueous compatible nanoparticles. More particularly, the present invention provides a method for producing aqueous compatible semiconductor nanoparticles by binding pre- modified ligands to the nanoparticles without the need for further post-binding modification to render the nanoparticles aqueous compatible. Nanoparticles modified in this way can exhibit enhanced fluorescence and stability compared to aqueous compatible nanoparticles producing using prior art methods requiring post-binding modification processes.