Carbonaceous nanoparticle layers prepared using candle soot by direct- and spray-based depositions

Abstract

To investigate the properties and structures of soot particles derived from candle combustion, two deposition routes were performed. In “Route-1,” the aerosol (soot) particles were collected by direct exposure of a substrate in a chamber with controlled airflows. In "Route-2,” deposited soot nanoparticles was transferred into suspension and subsequently, the deposition of particles on to the substrate was achieved by an electrospray. Raman spectral analysis has shown the difference of G-band intensity relative to D-band between hydrophobic and hydrophilic particle layers obtained from different collection regions of the candle flame. It also reveals the effect of airflows during the collection to the ratio of the D to G peak. Meanwhile, the Raman spectra of the particles seem invariant to the preparation methods of suspension and electrospray deposition process. From the curve gradient of spectroscopy (190–2500 nm) results, the electrospray-deposited particle layers (Route-2) show higher absorbance in the near-infrared region compared to direct-deposited particle layers (Route-1). This change in the spectrum may due to the change in morphology of nanoparticle layers formed by each route.