Shear rheology and 1H TD-NMR combined to low-field RheoNMR: Set-up and application to quiescent and flow-induced crystallization of polymers

Räntzsch, Volker; Özen, Mürüvvet Begüm; Ratzsch, Karl‐Friedrich; Guthausen, Gisela; Wilhelm, Manfred

doi:10.1063/1.4982990

Cited by 5 publications

(3 citation statements)

References 8 publications

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“…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.…”

Section: Introductionmentioning

confidence: 99%

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

Colbourne

Blythe

Barua

et al. 2018

Journal of Magnetic Resonance

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Nuclear magnetic resonance rheology (Rheo-NMR) is a valuable tool for studying the transport of suspended non-colloidal particles, important in many commercial processes. The Rheo-NMR imaging technique directly and quantitatively measures fluid displacement as a function of radial position. However, the high field magnets typically used in these experiments are unsuitable for the industrial environment and significantly hinder the measurement of shear stress. We introduce a low field Rheo-NMR instrument (H resonance frequency of 10.7MHz), which is portable and suitable as a process monitoring tool. This system is applied to the measurement of steady-state velocity profiles of a Newtonian carrier fluid suspending neutrally-buoyant non-colloidal particles at a range of concentrations. The large particle size (diameter >200μm) in the system studied requires a wide-gap Couette geometry and the local rheology was expected to be controlled by shear-induced particle migration. The low-field results are validated against high field Rheo-NMR measurements of consistent samples at matched shear rates. Additionally, it is demonstrated that existing models for particle migration fail to adequately describe the solid volume fractions measured in these systems, highlighting the need for improvement. The low field implementation of Rheo-NMR is complementary to shear stress rheology, such that the two techniques could be combined in a single instrument.

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Section: Introductionmentioning

confidence: 99%

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

Colbourne

Blythe

Barua

et al. 2018

Journal of Magnetic Resonance

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“…To compare and correlate macroscopic with microscopic properties and molecular structure with dynamics in tempera paint, we report in this work a bi‐technical approach to characterise this kind of paint by combining rheology and NMR relaxometry [16] . While rheological measurements give access to the macroscopic that is, viscoelastic properties (elastic modulus G′, loss modulus G′′ and yield stress), NMR relaxation rates ( R 1 ) measure the accessibility and the interaction of protons with the surfaces of the dispersed pigment on a shorter timescale.…”

Section: Figurementioning

confidence: 99%

Connecting Rheological Properties and Molecular Dynamics of Egg‐Tempera Paints based on Egg Yolk

et al. 2021

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Egg‐tempera painting is a pictorial technique widely used in the Middle Ages, although poorly studied in its physico‐chemical aspects until now. Here we show how NMR relaxometry and rheology can be combined to probe egg‐tempera paints and shed new light on their structure and behavior. Based on recipes of the 15th century, model formulations with egg yolk and green earth have been reproduced to characterize the physicochemical properties of this paint at the mesoscopic and macroscopic scales. The rheological measurements highlight a synergetic effect between green earth and egg yolk, induced by the interactions between them and the structural organisation of the system. 1H NMR relaxometry emphasizes the presence and the structure of a network formed by the yolk and the pigment.

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“…This approach is different from other Rheo‐NMR set‐ups, as its main purpose is the study of molecular dynamics rather than chemical structure via NMR spectroscopy or morphology via magnetic resonance imaging. Low‐field Rheo‐NMR can be used to study processes with changes in the molecular dynamics and macroscopic flow behavior such as the curing of resins, the cross‐linking of rubbers, or the crystallization of soft matter . Based on the changes in molecular dynamics, a compositional analysis of multiphase soft matter systems during start‐up and continued application of linear and nonlinear shear deformations can be obtained .…”

Section: Hyphenated Rheology Techniquesmentioning

confidence: 99%

Polymer Crystallization Studied by Hyphenated Rheology Techniques: Rheo‐NMR, Rheo‐SAXS, and Rheo‐Microscopy

Räntzsch

Özen

Ratzsch

et al. 2018

Macro Materials & Eng

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Rheological set‐ups with in situ analytical sensors, combine information on the flow and deformation behavior of soft matter, with simultaneous insights into structural and dynamic features. Furthermore, they permit the study of soft matter under well‐defined flow conditions. Herein are presented hyphenations of rheology and nuclear magnetic resonance (NMR), small angle X‐ray scattering (SAXS), and optical microscopy. They are employed to unravel relationships between the molecular dynamics, morphology, and rheology of crystallizing polymers. The results confirm a physical gelation process during polymer crystallization, mediated by the interaction of growing superstructures at volume fractions of 10–15%. The buildup of row‐nucleated structures during flow‐induced crystallization is found to reduce the time of gelation as detected by the rheological response. These investigations help to clarify the crystallization mechanism, structure–property relationships, and the hardening behavior of crystallizing polymers.

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Shear rheology and 1H TD-NMR combined to low-field RheoNMR: Set-up and application to quiescent and flow-induced crystallization of polymers

Cited by 5 publications

References 8 publications

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

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

Connecting Rheological Properties and Molecular Dynamics of Egg‐Tempera Paints based on Egg Yolk

Polymer Crystallization Studied by Hyphenated Rheology Techniques: Rheo‐NMR, Rheo‐SAXS, and Rheo‐Microscopy

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