The rheological characterization of HPG gels: Measurement of slip velocities in capillary tubes

Jiang, Ti-Qian; Young, A. C.; Metzner, A. B.

doi:10.1007/bf01331511

Cited by 69 publications

(26 citation statements)

References 23 publications

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“…The true shear rate can be corrected by subtracting 4u s /R from the apparent shear rate. Such a correction is also known as the Mooney correction (86,87), which can produce the corrected shear rate especially at high shear rate. The dependence of wall slip on the shear stress can give additional information on extrusion instability (88,89).…”

Section: Rotational Rheometermentioning

confidence: 98%

Rheological Measurements

2013

Encyclopedia of Polymer Science and Technology

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Rheology is the science to study the flow and deformation of matter. It becomes an important field in material science and engineering, food, biotechnology, and so on. The objects in rheological study are not the ideal solid and ideal fluid, which can be described by the Hookean elastic model and the Newtonian viscous model, respectively. Instead, the rheological study often focuses on materials that can exhibit viscous, elastic, and plastic behavior under different flow conditions. They are often termed as complex fluids or soft matter, which include polymers, gels, suspensions, emulsions, biofluids, foods, inks (1). In contrast to hydrodynamics, which often accounts for the complex flow behavior of simple fluids, simple geometry is utilized in rheological measurements to understand the rather complicated relationship between the mechanical input and output of complex fluids. The real flow fields encountered in many applications (such as polymer extrusion, injection molding, blow molding, fiber spinning, inkjet printing, coating) are rather complicated (2). It becomes a problem whether the rheological measurements that performed under simple flow fields are useful in understanding the complicated flow behaviors of complex fluids. Fortunately, it has been proved in many examples that the properties determined from simple rheological measurements are sufficient to quantify the material parameters in various constitutive equations, which have been used widely and successfully to simulate the flow behaviors in polymer processing (3-11). The most frequently used simple flow fields are simple shear flow and simple extensional flow.The simplest geometry that defines the simple shear is two infinite parallel plates separated by a distance h. The liquid is set between two plates with one plate moving parallel to the other (Fig. 1). In reality, when the length L and the width B are much larger than the gap h, the flow in the center regime resembles the flow between two infinite plates. It means that the edge effects are ignored in most experimental shear geometries. In rheological measurements, the flow between two plates should be laminar. Moreover, it is usually assumed that the velocity across the gap satisfies a linear profile. As shown in Fig. 1, if the bottom plate is fixed and the upper plate moves horizontally with the velocity V, the fluid velocity varies linearly from 0 at the bottom plate to V at the upper plate if the no-slip boundary condition is satisfied. The linear velocity profile generates a constant velocity gradient, which is known as the shear rate. Then, the flow field between two parallel plates is homogeneous in the shear rate. The homogeneous assumption is nontrivial in the rheological tests since the actual velocity

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Section: Rotational Rheometermentioning

confidence: 98%

Rheological Measurements

2013

Encyclopedia of Polymer Science and Technology

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“…4a, which is much larger than the apparent viscosity measured by the rheometer. It is noted that wall slip has been characterized using the capillary viscometer for borate crosslinked hydroxypropyl guar gels (Jiang et al 1986;Kesavan et al 1993). For zirconium crosslinked CMHPG, the velocity profile again shows wall slip and negligible flow in the bulk, indicating the shear stress is still below the yield stress of the sample.…”

Section: Figure 5-comparison Of First Normal Stress Difference For 0mentioning

confidence: 98%

Effects of Crosslinking Chemistry on Proppant Suspension in Guar Networks

Kishore

Maxey

et al. 2015

SPE International Symposium on Oilfield Chemistry

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Dynamic proppant suspension behavior of carboxymethyl hydroxypropyl guar (CMHPG) crosslinked with labile (reversible) and inert (irreversible) crosslinkers are quantified and compared in this work. In reversibly crosslinked CMHPG by borate, particle settling slows with increased imposed orthogonal shear rate and proppants remain suspended for long periods above a critical shear rate. On the contrary, in irreversible zirconium crosslinked CMHPG, particle settling is negligible at low shear rates, dramatically accelerating above a critical shear rate. Local flow field data was obtained to provide insight into the dramatically different particle settling behavior. It was observed that the slowing of particle settling with increased shear rate in borate crosslinked CMHPG originates from shear-induced gelation, which leads to significant increases to both viscosity and elastic stresses. For zirconium crosslinked CMHPG sheared at low shear rates, the local velocity profile is flat, indicating that the network remains intact with negligible flow in the bulk. Above the critical shear rate, the velocity profile becomes sloped, indicating breakup of the network. Therefore, reversibly crosslinked polymers suspend proppant better at high shear rates with an upper critical shear rate for proppant suspension, whereas irreversibly crosslinked polymers suspend proppant better at low shear rates with a lower critical shear rate for proppant suspension. These findings provide valuable guidance in terms of optimizing fracture fluid design to help maximize proppant transport into fractures.

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“…Jiang et al 5 also observed, with hydroxypropyl guar gels, that wall slip occurred more readily in tubes with smooth surfaces. The wall slip of gels was observed more readily in acrylic tubes, as compared to stainless steel tubes.…”

Section: Introductionmentioning

confidence: 94%

Effect of the surface roughness and construction material on wall slip in the flow of concentrated suspensions

Gulmus

Yilmazer

2006

J of Applied Polymer Sci

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Recent studies on polyethylene, elastomers, and thermoplastics have revealed that the construction material and surface roughness are two important factors affecting wall slip. In this study, to determine the true rheological behavior of model concentrated suspensions, a multiple-gap separation method was used in a parallel disk rheometer. The model suspensions studied were poly (methyl methacrylate) particles with an average particle size of 121.2 mm in hydroxyl-terminated polybutadiene. The aim of this study was to investigate the effect of disk R a in the range of 0.49-1.51 mm and disk construction ma-terial on the wall slip and the true viscosity of the model concentrated suspensions. The wall slip velocity and the viscosity were found to be independent of R a for particle size-to-disk R a ratios of 80-247. Also, the true viscosity was found not to be affected by the rheometer surface construction material. Glass surfaces resulted in the highest slip velocity, whereas aluminum surfaces resulted in the lowest slip velocity.

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The rheological characterization of HPG gels: Measurement of slip velocities in capillary tubes

Cited by 69 publications

References 23 publications

Rheological Measurements

Rheological Measurements

Effects of Crosslinking Chemistry on Proppant Suspension in Guar Networks

Effect of the surface roughness and construction material on wall slip in the flow of concentrated suspensions

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