Liquid-Liquid and Liquid-Air Interfacial Properties of Mixed Nanoparticle-Surfactant Systems (Abstract/Poster in atti di convegno)

Type
Label
  • Liquid-Liquid and Liquid-Air Interfacial Properties of Mixed Nanoparticle-Surfactant Systems (Abstract/Poster in atti di convegno) (literal)
Anno
  • 2007-01-01T00:00:00+01:00 (literal)
Alternative label
  • Ravera F.; Ferrari M.; Liggieri L.; Loglio G.; Santini E.; Zanobini A. (2007)
    Liquid-Liquid and Liquid-Air Interfacial Properties of Mixed Nanoparticle-Surfactant Systems
    in International Workshop on Bubble and Drop Interfaces 2007: B&D 2007, Granada, Spain
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • Ravera F.; Ferrari M.; Liggieri L.; Loglio G.; Santini E.; Zanobini A. (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#note
  • In: International Workshop on Bubble and Drop Interfaces 2007: B&D 2007 (Granada, Spain, 25-28 March 2007). Proceedings, pp. 02 - 02. , 2007. (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#descrizioneSinteticaDelProdotto
  • Solid particles of micro/nanometric dimension are used as stabilizers in emulsion and foam technology, often in association with surfactants. The effect of the surfactant/particle structure on the water/oil and water/air interfaces is then an important scientific and technological topic with many still open points. In fact, the particle attachment/segregation at the fluid interface is mainly governed by their hydophobicity/lipophilicity, which is determined by the surfactant adsorption on their solid interface. Thus the particle affinity for the interfacial layer, depends on the thermodynamic adsorption properties of the surfactant both at the liquid and at the solid particle interface. On the other side, especially when dynamic situation are concerned, like during emulsion or foam destabilisation, other kinetic aspects have to be taken into account. To deepen these aspects, in the study here presented, the interfacial properties of nanometric colloidal silica dispersions in the presence of a cationic surfactant (CTAB) are investigated. The equilibrium and dynamic interfacial tension of the dispersion-air and dispersion-oil interfaces have been measured as a function of the surfactant and particle concentration. For the same systems the interfacial rheology has also been investigated by measuring the dilational visco-elasticity as a function of the area perturbation frequency. These results are then crossed with the estimation of the surfactant adsorption on the silica particles, and also with the wettability properties of the macroscopic silica by CTAB solution, obtained by contact angle measurements both at liquid/air and liquid/liquid interfaces. By these multiple experimental study it has been possible to point out and analyse the key mechanisms determining the observed kinetic and equilibrium features. In particular, it has been found that an important role is played by the diffusion transport of particles from the bulk to the interface, the reorganisation of the mixed particle-surfactant layer at the interface and the surfactant redistribution between particle and fluid interface. (literal)
Titolo
  • Liquid-Liquid and Liquid-Air Interfacial Properties of Mixed Nanoparticle-Surfactant Systems (literal)
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