The use of Taguchi statistical tool for synthesis of carbon nanostructures by chemical vapor deposition from EPS

In a search for new alternatives for obtaining carbon nanostructures (CNSs) through more economical, environmentally friendly processes and for their possible industrial-scale production, chemical vapor deposition is the preferred method that can satisfy these requirements. This research proposes the synthesis of CNSs using expanded polystyrene as a precursor, with or without AISI 304 stainless steel as catalyst. Taguchi's design of experiments allowed to optimize the chemical vapor deposition process, in order to demonstrate that EPS is a possible sustainable source of carbon. Temperature and synthesis time were selected as variables. The obtained samples were characterized through scanning electron microscopy, energy dispersive spectroscopy; Fourier transformed infrared spectroscopy, X-ray diffraction, and Raman spectroscopy. The CNSs obtained by the catalyst usage showed smaller and more crystalline structures with Fe and Cr particles presence. All the samples demonstrated the presence of OH and C =O functional groups which can be useful for the application of CNSs as filler in different composites with polymer matrix for enhancement of their interaction. Due to their characteristics, the obtained carbon spheres are suitable for a variety of applications in electronics, energy storage, drugs delivery vehicles, composites, and others. Graphical abstract