Soot particles at the aqueous interface and effects on foams stability

Abstract

This work is focused on the physico-chemical characterization of carbonaceous nanometric particulate produced from controlled combustion sources and on its effects on dynamic interfacial tension and surface dilational rheology of aqueous interfaces and on foamability. Since large quantities of surfactants are introduced into waste waters and water bodies by industrial activities, the properties of carbon particulate–laden liquid interfaces have been investigated in connection with the presence of surfactants. Aim of this work is to evidence the occurrence of synergetic effects between carbonaceous particulate and surfactants in affecting the above properties.Two carbonaceous particulates have been selected as representative of aromatic and aliphatic soot. These particulates have been sampled from benzene and ethylene premixed laminar flames burning in fuel-rich conditions and characterized in terms of micro and nanostructures and size distribution. Water–air (W/A) interfacial properties of dispersions of the above particulate have been investigated in presence of hexadecyltrimethylammonium bromide (CTAB), a widely used cationic surfactant. The dynamic surface tension and the surface dilational rheological behaviour have been studied in relationship with foam stability for environmental purpose and, as perspective, to explore new techniques involving the set up of stable dispersion of carbon particulate for the synthesis of microporous materials to be employed in CO2 capture. Comparison with the results previously obtained with commercially available carbon black particles are also given.