Orientation and Relaxation of Polymer-clay Solutions Studied by Rheology and Small-angle Neutron Scattering
- Louisiana State University
- ORNL
- National Institute of Standards and Technology (NIST)
The influence of shear on viscoelastic solutions of poly(ethylene oxide) (PEO) and clay [montmorillonite, i.e., Cloisite NA+ (CNA)] was investigated with rheology and small-angle neutron scattering (SANS). The steady-state viscosity and SANS were used to measure the shear-induced orientation and relaxation of the polymer and clay platelets. Anisotropic scattering patterns developed at much lower shear rates than in pure clay solutions. The scattering anisotropy saturated at low shear rates, and the CNA clay platelets aligned with the flow, with the surface normal parallel to the gradient direction. The cessation of shear led to partial and slow randomization of the CNA platelets, whereas extremely fast relaxation was observed for laponite (LRD) platelets. These PEO-CNA networklike solutions were compared with previously reported PEO-LRD networks, and the differences and similarities, with respect to the shear orientation, relaxation, and polymer-clay interactions, were examined.
- Research Organization:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
- Sponsoring Organization:
- USDOE Office of Science (SC)
- DOE Contract Number:
- DE-AC05-00OR22725
- OSTI ID:
- 1003190
- Journal Information:
- Journal of Polymer Science, Part B: Polymer Physics, Vol. 42, Issue 17; ISSN 0887--6266
- Country of Publication:
- United States
- Language:
- English
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