Narrow Size Distribution of Spherical Metal Sulfide Nanoparticles

The high cost and low mechanical strength of windows and domes that protect the multimode sensors on missiles and maximize their mode of operation have been a concern for a long time for the Department of Defense. Crucial requirements for this application are: a) excellent infrared transmission, b) very good mechanical properties and c) ability to withstand harsh environmental conditions. Multispectral ZnS is well suited for high performance aperture systems that function across abroad wavelength spectrum (0.4 to 12 microns). However, ZnS prepared by chemical vapor deposition lack the mechanical strength and is very costly due to low deposition rates and the use of H2S that requires special safety precautions. A sintered compact powder by hot pressing nanoparticles prepared through an environmentally friendly process will eliminate the use of toxic chemicals and will dramatically decrease the cost of ZnS while improving its mechanical and optical properties. This will require the preparation of ZnS nanoparticles with almost mono-dispersed size distribution and regular morphology. In this Phase I project Lynntech will develop a low temperature, low cost (99.99%) ZnS and GaS spherical nanoparticles in the 35 nm to 50 nm range.