X-ray Scattering Measurements of Particle Orientation in a Sheared Polymer/Clay Dispersion

Journal Article · Fri Jan 20 04:00:00 EST 2012 · Rheologica Acta

DOI:https://doi.org/10.1007/s00397-010-0492-3· OSTI ID:1033791

Pujari, Saswati; Dougherty, Leah; Mobuchon, Christoph; Carreau, Pierre J; Heuzey, Marie-Claude; Burghardt, Wesley R ^[1]

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1. Ecole

We report steady and transient measurements of particle orientation in a clay dispersion subjected to shear flow. An organically modified clay is dispersed in a Newtonian polymer matrix at a volume fraction of 0.02, using methods previously reported by Mobuchon et al. (Rheol Acta 46: 1045, 2007). In accord with prior studies, mechanical rheometry shows yield stress-like behavior in steady shear, while time dependent growth of modulus is observed following flow cessation. Measurements of flow-induced orientation in the flow-gradient plane of simple shear flow using small-angle and wide-angle X-ray scattering (SAXS and WAXS) are reported. Both SAXS and WAXS reveal increasing particle orientation as shear rate is increased. Partial relaxation of nanoparticle orientation upon flow cessation is well correlated with time-dependent changes in complex modulus. SAXS and WAXS data provide qualitatively similar results; however, some quantitative differences are attributed to differences in the length scales probed by these techniques.

• Research Organization: Advanced Photon Source (APS), Argonne National Laboratory (ANL), Argonne, IL (US)
• Sponsoring Organization: NSF
• OSTI ID: 1033791
• Journal Information: Rheologica Acta, Journal Name: Rheologica Acta Journal Issue: 1 Vol. 50; ISSN 0035-4511; ISSN RHEAAK
• Country of Publication: United States
• Language: ENGLISH

Related Subjects

36 MATERIALS SCIENCE
CLAYS
ORIENTATION
POLYMERS
RELAXATION
SCATTERING
SHEAR
TRANSIENTS