Multivariate Optimization of Carbon Nanotubes Synthesis from Nonconventional Precursor using Box-Behnken Design towards Higher Yield

Optimization techniques play a significant role in improving the performance and efficiency of a product (or) process. In general these techniques results in maximizing the desired ones and minimizing the non-desired ones. In this context, we identified and optimized the parameters of chemical vapour deposition proc ess to achieve higher yield of carbon nanotubes. We selected the most abundantly available plastic waste, Polystyrene a major source of environment degradation to be the precursor. Polystyrene was thermal degraded in t o oil by spray pyrolysis. The extracted PS oil was utilized as resource for producing carbon nanotubes through horizontal fluidized bed reactor. Reaction temperature, catalyst/ support material ratio, and gas flow rate were identified as the paramount parameters that affect the yield. The experimental run orders to optimize the process was obtained by Box Behnken design, a response surface methodology scheme. In total 17 experimental trials were conducted and the respective yield was found. The parametric combination corresponding to higher yie ld was recognized. The obtained optimum parameters can be readily adapted to any laboratory level CVD synthesis. In this effort Field Emission Scanning Electron Microscope, High-resolution transmission electron micro scopy and Raman spectroscopy were adapted to examine the microstructure and morphology respectively.