CINNO Research Industry Information, a research group of the Department of Optical Science at the US Naval Research Laboratory (Washington, D.C.) is developing a transparent luminescent material. The material is a Thiol-yne nanocomposite polymer used to encapsulate quantum dot (QD) materials. Potential applications for this technology include flexible, stretchable, and shatter-resistant displays.
The team recently published a report on the subject, entitled "Photoluminescent Quantum Dot Mercaptoyne Nanocomposites Prepared by Thermal Curing or Photopolymerization."
Two possible QD mercaptoalkyne nanocomposite manufacturing processes (Image source: Display Daily)
"Experiments have shown that polymers prepared using mercaptoalkyne can exhibit rubber properties, rigidity, high refractive index properties, transparency properties, and stability at high temperatures, etc., depending on the choice of starting components." In addition, they can Incorporate other nanoparticles to modify. The above-mentioned ideal material properties make mercaptoalkyne polymer materials have great application potential in some fields, such as various applications based on photoluminescent materials.
A specific goal of these studies is to verify the feasibility of using mercaptoalkyne polymers prepared by mercaptoalkyne chemistry as QD carriers. The feasibility here lies in whether this solution can produce such a photoluminescent QD mercaptoyne nanocomposite to ensure that the characteristic luminescence of its QD is not affected by polymerization or quenching.
In the current work, researchers have synthesized new ligands and used them for the functionalization of QD materials of various diameters (in chemistry, a ligand is an ion or Molecule. Functionalization is the process of adding new functions, features, and abilities to a material by changing the surface chemical properties of a particular material.)
All the process required to incorporate a functionalized QD into a thioalkyne prepolymer is to add the thioalkyne prepolymer to the QD solution. This process is performed in a glass vial and then stirred vigorously for a few seconds. At this time, the prepolymer can be drip-coated or spin-coated on a substrate or poured into a mold. The material is then polymerized through a UV or thermal curing process to make a QD mercaptoalkyne nanocomposite polymer. The following figure shows these two possible material manufacturing processes.
During UV curing, the transparent nanocomposite emits light of the desired color in relation to the QD size. This proves that QD can be incorporated into mercaptoalkyne polymer materials without significantly changing the emission color of QD. The researchers also confirmed the uniformity of QD distribution throughout the polymer material. The figure below illustrates the luminescence characteristics of these QD-containing polymer samples.
Samples of mercapto polymer materials (Image Source: Display Daily)
Left and middle: A sample of a mercaptoyne polymer material containing red QD under external environmental conditions; right: a sample of a mercaptoyne polymer material under ultraviolet light. The red QD (1.5 μm) is shown in the matrix in the figure.
In their article, the researchers concluded that their invention "made a material with customized optical properties based on the monomers and / or incorporated QDs used in the prepolymer formulation."
They further explained that this method of QD functionalization and synthesis of QD and mercaptoyne polymer materials is feasible, and summarized in the report the synthesis of another type of QD and nanoparticles.
The US Patent and Trademark Office recently published patent applications filed by the Naval Research Laboratory based on the technology described in this article. The patent application has an application number of 16 / 153,357. They collaborated with TechLink, the laboratory's technology transfer office, to commercialize this government-funded research effort through businesses.