i-Rheo: Measuring the materials' linear viscoelastic properties “in a step”!

We present a simple new analytical method for educing the materials’ linear viscoelastic properties, over the widest range of experimentally accessible frequencies, from a simple step-strain measurement, without the need of preconceived models nor the idealization of real measurements. This is achieved by evaluating the Fourier transforms of raw experimental data describing both the time-dependent stress and strain functions. The novel method has been implemented into an open access executable “i-Rheo,” enabling its use to a broad scientific community. The effectiveness of the new rheological tool has been corroborated by direct comparison with conventional linear oscillatory measurements for a series of complex materials as diverse as a monodisperse linear polymer melt, a bimodal blend of linear polymer melts, an industrial styrene-butadiene rubber, an aqueous gelatin solution at the gel point and a highly concentrated suspension of colloidal particles. Author to whom correspondence should be addressed; electronic mail: [email protected] VC 2016 by The Society of Rheology, Inc. J. Rheol. 60(4), 649-660 July/August (2016) 0148-6055/2016/60(4)/649/12/$30.00 649 Redistribution subject to SOR license or copyright; see http://scitation.aip.org/content/sor/journal/jor2/info/about. Downloaded to IP: 130.209.115.82 On: Wed, 15 Jun 2016 09:05:04 The broadband nature of the new method and its general validity open the route to a deeper understanding of the material’s rheological behavior in a variety of systems. VC 2016 The Society of Rheology. [http://dx.doi.org/10.1122/1.4953443]