Soot particles at the aqueous interface and effects on foams stability

• Published in: Colloids and surfaces. A, Physicochemical and engineering aspects Vol. 413; pp. 216 - 223
• Main Authors: Santini, E., Guzmán, E., Ravera, F., Ciajolo, A., Alfè, M., Liggieri, L., Ferrari, M.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05.11.2012
• Subjects: benzene; burning; Carbon; carbon dioxide; Carbon soot; Carbonaceous nanoparticles; cationic surfactants; colloids; Combustion; dispersions; ethylene; Foams; Interfacial properties; Joints; Liquids; methodology; nanomaterials; particulates; rheological properties; rheology; Stability; Surface chemistry; surface tension; Surfactants; Foams; Carbon soot; Interfacial properties; Carbonaceous nanoparticles
• ISSN: 0927-7757; 1873-4359
• DOI: 10.1016/j.colsurfa.2012.02.028

[Display omitted] ► Interfacial properties evidence the synergistic interaction between combustion derived particles and cationic surfactants. ► Nanoparticle aggregates are formed in the dispersion with hydrophilic interstices able to act as adsorption sites for CTAB. ► The interfacial tension and the dilational rheology of the aqueous dispersions is related to the ability to form stable foams. ► Different structure and morphology of the particles account for the different behavior of the interfacial properties and foam. 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.