Influence of the collecting substrate's nature on structure and properties of Gajal soot

Abstract

Gajal soot, a black carbonaceous residue, was prepared by burning sesame oil with the aid of threaded cotton in a copper oil lamp. Substrates made of clay, iron, and bronze were separately used for the collection of the Gajal soot, herein named as GS-CS, GS-IS, and GS-BS, respectively. The physicochemical properties of the soot particles were characterized using UV-visible and Raman spectroscopy, X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). The disordered structure of each soot particle was revealed by Raman spectra through the appearance of D-band and G-band around 1336 cm^-1and 1590 cm^-1, respectively. XRD spectra disclosed the semicrystalline natures of soot particles, with crystallite sizes of 1.40 nm,1.73 nm, and 1.50 nm for GS-CS, GS-IS, and GS-BS, respectively. The agglomerated and irregular-spherical shape of soot particles having a diameter within the range of 20-40 nm for GS-CS and GS-IS, while 40-80 nm for GS-BS, was observed by SEM image. The variation in the particle diameter of soot derived from different substrates was attributed to the collector substrate roughness. The study reveals that the size and optical properties of soot particles show insignificant variation depending on the type of substrate employed for soot collection.