There are several methods for synthesis of nanoparticles of binary compounds like CdS, PbS, Ce02, Si02, Mo2C, W2C in both solution phase and vapor phase. Sonochemical methods are generally differentiated because of the unconventional heating method using ultrasound induced caviation. This results in very high local temperatures leading to unique conditions in the bath as opposed to conventional heating methods. In batch sonochemistry, the process is plagued with lack of adequate control on particle size, long processing times for completion and generation of unusable waste particles. These issues could be remedied by the usage of high intensity ultrasound in continuous flow for production of nanoparticles. A novel, low-cost approach and high volume production of nanoparticles using continuously flowing medium exposed to ultrasound is devised. The method produces nanoparticles of high size uniformity with high aspect ratio shapes and uncommon crystal structure. A micromixing stage upstream before the mixed reactants enter the sonochemical reactor helps in reducing the processing time from couple of hours to less than a minute.
Features & Benefits
Background of Invention
Cadmium sulfide nanoparticles generally exhibit quantum confinement effects when the particle size is less than 10 nm and approaches the Bohr exciton radius. It is a widely used buffer material in solar cells owing to its wide band transmission of solar light and hence used as a window layer in photovoltaic devices. Sonochemical synthesis permits the rapid heating of reactant baths by acoustic cavitation leading to high local temperatures.
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