| Autor: |
Eduardo Mendes, M. Heinrich, Ourides Santin, Stephen J. Picken, Sebastien Viale |
| Jazyk: |
angličtina |
| Rok vydání: |
2003 |
| Předmět: |
|
| Zdroj: |
Journal of applied crystallography 36, 1000-1005 (2003). doi:10.1107/S0021889803013761 |
| DOI: |
10.1107/S0021889803013761 |
| Popis: |
Solutions of a rigid polyelectrolyte molecule, sulfo-poly(phenyleneterephthalamide) (SPTTA), in deuterated water have been investigated using small-angle neutron scattering. At low concentrations (1 wt%) the scattering spectrum presents a soft maximum similar to that of the interaction of rod-like objects. Two counterions are used, H+and Li+, and it is shown that aggregation is favoured as the proportion of Li+counterions increases. When kept at rest at room temperature, the solutions exhibit spontaneous birefringence. A 1 wt% solution was investigated under shear and it is shown that a very small shear rate is needed to produce a very strong alignment of rod-like objects. Such alignment saturates at high shear rates. Upon cessation of shear, a very long relaxation time is observed. The set of results strongly suggest aggregation of rigid polyelectrolyte molecules into long needles exhibiting very small cross sections. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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