Polythiol Quantum Dot Ligands for Resin-Soluble Stable Nanostructures
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Solution Overview
Problem
Existing quantum dots have hydrophobic ligands that limit their solubility in a wide range of organic media, leading to instability and deterioration of optical properties when exposed to resin formulations, necessitating improved nanostructure compositions and resin mixes for enhanced stability and optical performance.
Innovation Solution
The use of polythiol ligands with pendant moieties, such as those described by formula I, are dispersed on the surface of nanostructures to enhance solubility and stability, allowing for ligand exchange to replace hydrophobic ligands with more stable and soluble alternatives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If hydrophobic ligands are used on quantum dot surfaces, then colloidal stability is achieved, but solubility in organic media is limited and optical properties deteriorate in resin formulations
Solution Approach 1:
The patent changes the chemical parameters of the ligands by introducing polythiol compounds with specific molecular structures (formula I) that have both binding capability to the quantum dot surface and solubilizing pendant moieties. This parameter change enables the ligands to provide both colloidal stability and enhanced solubility in a wide range of organic media, resolving the contradiction between stability and adaptability.
Solution Approach 2:
The patent uses composite ligand structures combining polythiol backbones with various solubilizing pendant moieties (such as carboxylic acid, ester, amine, or hydrocarbon groups). These composite ligand molecules integrate multiple functions: binding to the quantum dot surface while simultaneously providing solubility in different organic solvents and resin formulations, thus resolving the contradiction between colloidal stability and solubility versatility.
2Adaptability or versatility
If carboxylic acid functionalized polymeric ligands are used, then solubility in resin formulations is achieved, but optical properties deteriorate due to displacement by thiol groups
Solution Approach 1:
The patent introduces polythiol ligands as intermediary molecules that mediate between the quantum dot surface and the resin formulation. These polythiol ligands have a dual function: they bind strongly to the quantum dot surface (preventing displacement by resin thiols) while simultaneously providing solubility in resin formulations through their pendant moieties. This intermediary role resolves the contradiction between solubility and optical property stability.
Solution Approach 2:
The patent applies preliminary anti-action by using polythiol ligands that preemptively bind to the quantum dot surface, creating a protective layer that prevents subsequent displacement by thiol groups from the resin formulation. This preliminary binding action counteracts the harmful effect of thiol displacement before it can occur, thereby maintaining optical properties while achieving solubility.
3Adaptability or versatility
If ligand exchange is performed to improve solubility, then solubility in organic media increases, but full width at half-maximum broadens and burn-in variations occur
Solution Approach 1:
The patent optimizes the parameters of the polythiol ligands, including the length and structure of the pendant moieties and the number of thiol groups, to achieve the right balance between solubility and optical property stability. By carefully controlling these parameters, the patent enables ligand exchange that improves solubility while minimizing FWHM broadening and burn-in variations, thus resolving the contradiction between solubility and manufacturing precision.
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 polythiol ligands improve the solubility and stability of nanostructures in various solvents and resins, maintaining optical properties and reducing the risk of aggregation, thereby enhancing the performance of nanostructure films.
Implementation Method 1
Ligand exchange procedures have been performed using either a polyethylene glycol (PEG) based polymeric ligand functionalized with an amine or a carboxylic acid
Implementation Method 2
Metal thiolate bonds have been found to be stronger than both metal carboxylate and metal phosphonate bonds
Implementation Method 3
The polythiol ligand with pendant moieties increase the solubility of the nanostructures in solvents and resins
Implementation Method 4
a series of poly(ethylene glycol)-based bidentate ligands were produced that showed a strong interaction with CdSe/ZnS (core/shell) quantum dots and gold nanoparticles and promoted their dispersion in aqueous solutions
Implementation Method 5
Organic molecules bind to the inorganic surfaces of quantum dots providing both colloidal stability and terminating the crystalline lattice of the material reducing the number of surface trap states caused by dangling bonds
Data Source
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AI summary
The present invention provides nanostructure compositions and methods of producing nanostructure compositions. The nanostructure compositions comprise a population of nanostructures comprising polythiol ligands with pendant moieties. The polythiol ligand with pendant moieties increase the solubility of the nanostructures in solvents and resins. The present invention also provides nanostructure films comprising the nanostructure compositions and methods of making nanostructure films using the nanostructure compositions.