THERMAL AND STRUCTURAL STUDIES OF COPPER-BASED NANOPARTICLES PRODUCED BY SOL-GEL PROCESSING

摘要

CuO particles produced by a sol-gel method show a general increase in particle size as annealing temperature is increased. This is supported by XRD, thermal analysis, and TEM data. The CuO to Cu_2O transition temperature increases as particle size increases, from 1031.5℃ to 1049.4℃ for particles annealed at 200℃ and 1000℃, respectively. The particles tend to adhere to one another as the annealing temperature increases, many form oblong chains of micron-sized particles in the 600℃-800℃ annealing temperature range. The existence of these chains causes a splitting of the transitions seen in the DTA data. By the 1000℃ annealing temperature, the particles have uniformly formed conglomerates that are 30um in size. Adding SiO_2 to the sol-gel process and producing CuO-SiO_2 particles completely eliminates any CuO-Cu_2O transitions for molar concentrations as low as 1.0% SiO_2. Further studies will be performed on these particles.