Innovative Zinc Sulfide Nanoparticles for Enhanced Photonic Crystal Applications

University of Pittsburgh researchers have developed a process for synthesizing highly monodispersed zinc sulfide (ZnS) nanoparticles. These nanoparticles are suitable for use in photonic crystals and can significantly improve the diffraction efficiency of crystalline colloidal arrays (CCAs). The high refractive index of ZnS makes it an excellent candidate for various optical applications, including sensors, optical components, switches, paints, coatings, and cosmetics.

Description

The invention involves the synthesis of ZnS nanoparticles through the controlled precipitation of zinc nitrate and thioacetamide in ethylene glycol. The process allows for fine-tuning of particle size by adjusting the concentrations of nitric acid and water, resulting in highly monodispersed nanoparticles ranging from 18 nm to 2.1 µm. These nanoparticles can be used to create CCAs that Bragg-diffract light in the visible region, enhancing their potential for various optical applications.

Applications

- Sensors
- Optical components
- Switches
- Paints and coatings
- Cosmetics

Advantages

The high refractive index of ZnS (~2) is significantly higher than that of polymeric or silica spheres, which are commonly used in photonic crystals. This results in improved diffraction efficiency and better performance in optical applications. Additionally, the process allows for precise control over particle size, enabling the production of nanoparticles tailored to specific needs.

Invention Readiness

The invention is currently in the development stage, with ongoing efforts to fine-tune the process to improve yield and increase the charge of the nanoparticles by coating them with polystyrene (PS). The next steps include building a prototype sensor based on the photonic crystal array.

IP Status

https://patents.google.com/patent/US20080064788A1