Narrow Size Distribution of Spherical Metal Sulfide Nanoparticles

Crucial requirements for missile windows and domes include (i) excellent infrared transmission, (ii) ability to withstand extraordinary mechanical, thermal stresses and (iii) harsh environmental conditions. Multi-spectral ZnS has high transparency in a wide spectral range (0.4 m to 12 m). It is the material of choice for long wave-infrared and semi-active laser domes. The current method of preparation typically uses Chemical Vapor Deposition (CVD). However ZnS CVD has relatively low hardness which limits its use especially for air-borne military systems where particle or rain erosion may occur. A sintered compact powder by hot pressing nanoparticles prepared through a green process will eliminate the use of toxic chemicals and decrease the cost of ZnS while improving its mechanical and optical properties. During the Phase I project Lynntech developed a low temperature, green process for production of ZnS nanoparticles. This process is easily scalable and its simplicity will have an impact on the final goal cost of $500/kg of ZnS will be achieved. The goal of the Phase II project will be to demonstrate synthesis rates between 2-10 kg of nanopowder material on a daily basis with emphasis on purity (99.99%) and uniform size distribution.