Probing the dynamics of high-viscosity entangled polymers under shear using Neutron Spin Echo spectroscopy

Direct measurement of topological interactions in polymers under shear using neutron spin echo spectroscopy

“…For shear rates of half the inverse of τ D we could not detect disentanglement. Still our experiment shows that direct measurement of topological interactions in polymers under shear by means of NSE is possible up to large Fourier times, about three orders of magnitude larger than reported previously 41 , for shear rates approaching the inverse τ D of PDMS. Experiments on more rigid polymers, polymers with longer τ D or at higher shear rates should reveal possible disentanglement in future studies.…”

“…Rheo-NSE measurements require shear devices that do not influence the neutron beam polarisation, and the ability to, up to sufficiently high Fourier times, correct for the phase shifts and depolarisation induced by Doppler scattering. To provide steady shear to the polymer melt we designed an air-driven and non-magnetic vertical cone-plate shear cell 41,42 with a cone angle and radius of 2.86° and 30 mm, respectively (for a schematic see Fig. 4, panel a)).…”

Direct Measurement of Topological Interactions In Polymers under Shear Using Neutron Spin Echo Spectroscopy

“…For shear rates of half the inverse of τ D we could not detect disentanglement. Still our experiment shows that direct measurement of topological interactions in polymers under shear using NSE experiments are possible up to large Fourier times, about three orders of magnitude larger than reported previously 41 , for shear rates approaching the inverse τ D of PDMS. Experiments on more rigid polymers, polymers with longer τ D or at higher shear rates should reveal possible disentanglement in future studies.…”

Direct Measurement of Topological Interactions In Polymers under Shear Using Neutron Spin Echo Spectroscopy

“…To provide steady shear to the polymer melt we used an air-driven and non-magnetic vertical cone-plate shear cell 41,42 with a cone angle and radius of 2.86 • and 30 mm, respectively (for a schematic see Figure 4, panel a)). All neutron scattering experiments were done on the instruments D22 and IN15 (both Institut Laue-Langevin, Grenoble) with preliminary NSE data taken at SNS-NSE (Oak Ridge National Laboratory).…”