Molecular Dynamics of Polymer Composites Using Rheology and Combined RheoNMR on the Example of TiO₂-Filled Poly(n-Alkyl Methacrylates) and Trans-1,4-Polyisoprene

Validation of a low field Rheo-NMR instrument and application to shear-induced migration of suspended non-colloidal particles in Couette flow

“…Permanent magnet systems also offer the advantage of portability [15]. Low field magnets have been used previously to provide relaxation time measurements of liquid samples in conjunction with shear rheology measurements [16][17][18]. The usual Rheo-NMR experiment lacks a direct measure of shear stress although custom systems have been proposed that combine NMR and torque sensors [19,20], albeit still based on superconducting magnets with limited industrial application.…”

Rheo‐NMR in food science—Recent opportunities

“…However, torque and NMR data could be acquired successively (much in the spirit of the work cited above) using the same shear geometry, yielding NMR relaxation data, or 1D velocity profiles across the sheared material in addition to the separately measured shear stress. Later developments lifted this limitation, now providing low field Rheo‐NMR accessories that can be fitted to commercial rheometers, providing simultaneously the capabilities of high end rheometry coupled with NMR relaxometry …”

“…Later developments lifted this limitation, now providing low field Rheo-NMR accessories that can be fitted to commercial rheometers, providing simultaneously the capabilities of high end rheometry coupled with NMR relaxometry. [39][40][41][42] Although Rheo-NMR was initially developed and mainly used with superconducting high field NMR systems, [2,43,44] only a few attempts have been reported to record rheological behavior simultaneously with NMR data. A notable exception was the acquisition of 2 H spectra while measuring torque in the meantime, [45] thus correlating shear-induced molecular alignment of side-chain liquid-crystalline polymers with their shear dependent viscosity.…”

Hyphenated low‐field NMR techniques: combining NMR with NIR, GPC/SEC and rheometry

“…A different approach for rheoNMR is the use of a permanent magnet‐based NMR unit. Here, three approaches should be mentioned: The first method exploits the combination of capillary rheometry with NMR velocimetry and relaxometry, the second one is based on a benchtop spectrometer with an attached steady‐shear device and the third method uses oscillatory shear rheometry based on a commercial strain‐controlled rheometer in combination with a portable NMR unit . With the latter, it is possible to study molecular dynamics of highly viscous polymer melts by TD‐NMR relaxometry under a variety of rheological conditions resulting in the capability to perform rheometric and NMR experiments simultaneously.…”

“…injection molding. In a recent study, the crystallization of trans‐polyisoprene (t‐PI, gutta percha) was studied, which is a biodegradable polymer that is used for dental impression. It has a low melting point of T M ≈ 60 °C making it a good model system for a combined rheoNMR experiment.…”