Phase Coexistence in a Dynamic Phase Diagram. Issue 11 (17th June 2015)

• Record Type: Journal Article
• Authors: Gentile, Luigi; Coppola, Luigi; Balog, Sandor; Mortensen, Kell; Ranieri, Giuseppe A.; Olsson, Ulf
• Is Part Of: Chemphyschem. Volume 16:Issue 11(2015)
• Page Start: 2459
• Page End: 2465
• Publication Date: 2015-06-17
• Subjects: Chemistry, Physical and theoretical -- Periodicals; 541.05
• DOI: 10.1002/cphc.201500237
• Languages: English
• ISSNs: 1439-4235

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>Metastability and phase coexistence are important concepts in colloidal science. Typically, the phase diagram of colloidal systems is considered at the equilibrium without the presence of an external field. However, several studies have reported phase transition under mechanical deformation. The reason behind phase coexistence under shear flow is not fully understood. Here, multilamellar vesicle (MLV)‐to‐sponge (L₃) and MLV‐to‐L_α transitions upon increasing temperature are detected using flow small‐angle neutron scattering techniques. Coexistence of L_α and MLV phases at 40 °C under shear flow is detected by using flow NMR spectroscopy. The unusual rheological behavior observed by studying the lamellar phase of a non‐ionic surfactant is explained using ²H NMR and diffusion flow NMR spectroscopy with the coexistence of planar lamellar–multilamellar vesicles. Moreover, a dynamic phase diagram over a wide range of temperatures is proposed.</p> </abstract>