The aim of the present work is to illustrate and discuss an application of rheo-NMR techniques in the investigation of the flow micro-morphology of a rheo-thinning fluid. The viscoelastic material is composed by weakly hydrated nonionic Wormlike Micelles (WM), stabilized by the biocompatible phospholipid in an organic solvent (lecithin organogel). By applying rheo-NMR techniques, such as micro-imaging and flow velocimetry in Couette flow, to lecithin organogels in the concentrated isotropic phase, a new phase nucleating inhomogeneously at the inner rotating cylinder showing periodic fluctuations in space in some cases, has been identified for applied shear rates within the isotropic-nematic stress plateau. On the other hand, evident slippage phenomena have been found in flow regimes consistent with a full shear-induced nematic state. Bulk rheometric investigations executed in oscillatory, steady state and transient mode have been finally carried out to bridge different flow micro-heterogeneities detected by rheo-NMR with a variety of mechanical responses manifested by lecithin WM.
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1039/c6ra00206d|
|Codice identificativo ISI:||WOS:000374045000014|
|Codice identificativo Scopus:||2-s2.0-84964489929|
|Titolo:||Flow-induced structures observed in a viscoelastic reverse wormlike micellar system by magnetic resonance imaging and NMR velocimetry|
|Appare nelle tipologie:||1.1 Articolo in rivista|