Tuesday, October 18, 2011
Exhibit Hall B (Minneapolis Convention Center)
As technology grows, more interest has been placed on semiconductors, specifically copper oxide (CuO) semiconductors, due to their electronic and optoelectronic applications. For these applications the size of CuO is very important. In this study, flame spray pyrolysis (FSP) was used to create nearly spherical CuO nanoparticles with an aspect ratio 1.2-1.3. To control the size of these particles flame temperature, residence time and precursor concentration were varied. As the precursor concentration increased from 0.5% to 35% w/w, primary particle size increased from 7±2 to 20±11nm in diameter. Larger primary particle size was observed in the low gas flow system (set B) due to the long residence time in high temperature zone. For the dependence of temperature on particle size, particles grew to similar size, i.e. ~11 nm, in both flame conditions within the hot temperature zone (80% of melting point of CuO) but particle having longer residence time, i.e. 550 ms in set B, the standard deviation of particle size is 45% larger than particle with 66 ms as residence time in set A. Liquid nitrogen was added as a quench to the post temperature zone of the system. Particle size decreased down to 35% of original size.