Shear-induced anisotropy of concentrated multiwalled carbon nanotube suspensions using x-ray scattering
| Autor: | Wesley R. Burghardt, Alan H. Windle, J.W. Gilman, Krzysztof K. K. Koziol, Saswati Pujari, Sameer S. Rahatekar |
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| Rok vydání: | 2011 |
| Předmět: |
Nanotube
Materials science Shear thinning Scattering Small-angle X-ray scattering Mechanical Engineering Condensed Matter Physics Condensed Matter::Soft Condensed Matter Physics::Fluid Dynamics Shear modulus Shear rate Mechanics of Materials Newtonian fluid General Materials Science Composite material Shear flow |
| Zdroj: | Journal of Rheology. 55:1033-1058 |
| ISSN: | 1520-8516 0148-6055 |
| DOI: | 10.1122/1.3609854 |
| Popis: | X-ray scattering is used to measure particle orientation in concentrated multiwalled carbon nanotube (MWNT) suspensions under shear flow. MWNTs were dispersed in a Newtonian suspending fluid (uncured epoxy). The dispersions exhibit shear thinning, approaching the matrix viscosity at high shear rates. This is accompanied by progressive development of MWNT orientation along the flow direction with increasing shear rate. The impact of MWNT aspect ratio and concentration on steady-state orientation is explored. In one sample (2 wt. % dispersion of short MWNTs), orientation was measured in both the flow-gradient (1-2) and flow-vorticity (1-3) planes of shear flow to provide a more complete picture of the three-dimensional orientation state. Also in this sample, 1-3 plane measurements were conducted using both small- and wide-angle x-ray scattering (SAXS and WAXS). While the two methods produce qualitatively similar results, WAXS-derived measures of flow-induced anisotropy are consistently larger than SAXS data... |
| Databáze: | OpenAIRE |
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