A three-dimensional vector lattice model for a mixture of water, oil and amphiphile is considered on the simple cubic lattice. For a balanced system with equal water and oil concentrations the ground state exhibits, when the surfactant is strong, an ordered bicontinuous structure in addition to pure oil/water and pure surfactant states. The model is transformed, integrating out exactly the surfactant orientational degrees of freedom, in an effective spin-1 model with two-, three, five-and seven-body interactions with temperature dependent interaction strengths. This effective model is then investigated using the local mean-field approximation. The phase diagram of the model is derived and discussed, with particular attention to the structured ordered phase. In the disordered phase a microemulsion region is also found.

Structured phases of a three-dimensional vector lattice model for oil-water-surfactant mixtures / Buzano, Carla; L. R., Evangelista; Pelizzola, Alessandro. - In: MOLECULAR CRYSTALS AND LIQUID CRYSTALS SCIENCE AND TECHNOLOGY. SECTION A, MOLECULAR CRYSTALS AND LIQUID CRYSTALS. - ISSN 1058-725X. - 290:(1996), pp. 41-48. (Intervento presentato al convegno 2nd Italian-Liquid-Crystal-Society(SICL) Meeting tenutosi a Ravenna nel May 30-Jun 01, 1996) [10.1080/10587259608031890].

Structured phases of a three-dimensional vector lattice model for oil-water-surfactant mixtures

BUZANO, Carla;PELIZZOLA, ALESSANDRO
1996

Abstract

A three-dimensional vector lattice model for a mixture of water, oil and amphiphile is considered on the simple cubic lattice. For a balanced system with equal water and oil concentrations the ground state exhibits, when the surfactant is strong, an ordered bicontinuous structure in addition to pure oil/water and pure surfactant states. The model is transformed, integrating out exactly the surfactant orientational degrees of freedom, in an effective spin-1 model with two-, three, five-and seven-body interactions with temperature dependent interaction strengths. This effective model is then investigated using the local mean-field approximation. The phase diagram of the model is derived and discussed, with particular attention to the structured ordered phase. In the disordered phase a microemulsion region is also found.
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/1397839
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo