A new dielectric effect in viscous liquids

¹ Università Statale di Bergamo, Facoltà di Ingegneria, viale Marconi 5, 24044 Dalmine (BG), Italy
² Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Complesso Universitario di Monte S. Angelo, via Cinthia, 80126 Naples, Italy
³ Istituto Nazionale di Fisica Nucleare, Sezione di Milano, via Celoria 16, 20133 Milan, Italy

^a e-mail: Salvatore.Esposito@na.infn.it
^b e-mail: Giovanni.Salesi@unibg.it

Received: 13 March 2012
Accepted: 15 May 2013
Published online: 13 June 2013

Abstract

An accurate experimental and theoretical study has been performed about a phenomenon, not previously reported in the literature, occurring in highly viscous liquids: the formation of a definite pipe structure induced by the passage of a heavy body, this structure lasting for quite a long time. A very rich phenomenology (including mechanical, optical and structural effects) associated with the formation of the pipe has been observed in different liquids. Actually, the peculiar dynamical evolution of that structure does not appear as a trivial manifestation of standard relaxation or spurious effects. In particular, we have revealed different time scales during the evolution of the pipe and a non-monotonous decrease of the persistence time with decreasing viscosity (with the appearance of at least two different maxima). We put forward a microscopic model, consistent with the experimental data, where the pipe behaves as a “dielectric shell” whose time evolution is described through a simple thermodynamical approach, predicting several properties effectively observed.