Is there a relation between the relaxation time measured in CaBER experiments and the first normal stress coefficient?

Zell, Andreas; Gier, S.; Rafaı̈, Salima; Wagner, Christian

doi:10.1016/j.jnnfm.2010.06.010

Cited by 59 publications

(46 citation statements)

References 28 publications

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“…We compare our results with those previously reported, by both pure shear and CaBER measurements. 28 Furthermore, we compare our data on those same solutions with theoretical scaling laws for λ as a function of concentration available in the literature. 35,36 2.…”

Section: Introductionmentioning

confidence: 96%

“…22 Because of the steady-state conditions of this kind of experiment, the measure might seem easier than the one through linear oscillations. 22 However, values of N 1 are typically rather low and are scattered, 28 and so it is difficult to extract an accurate value for λ from this method.…”

Section: Introductionmentioning

confidence: 99%

“…Specifically, it has been demonstrated that, for polyethylene oxide and polyacrylamide solutions, λ values taken by CaBER experiments are about forty times larger than those derived from N 1 measurements in shear. 28 It so appears that an accurate method for measuring relaxation times of an important class of non-Newtonian fluids (i.e., with low elasticity) is missing. As previously mentioned, this is a relevant issue in microfluidic applications using viscoelastic fluids, because the relaxation time is needed in the design formulas of focusing and separation devices, [9][10][11]18,19 and an erroneous estimate would result in under/oversized devices.…”

Section: Introductionmentioning

confidence: 99%

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Rheometry-on-a-chip: measuring the relaxation time of a viscoelastic liquid through particle migration in microchannel flows

et al. 2015

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A novel method to estimate the relaxation time of viscoelastic fluids, down to milliseconds, is here proposed. The adopted technique is based on the particle migration phenomenon occurring when the suspending viscoelastic fluid flows in microfluidic channels. The method is applied to measure the fluid relaxation times of two water-glycerol polymer solutions in an ample range of concentrations. A remarkable improvement in the accuracy of the measure of the relaxation time is found, as compared with experimental data obtained from shear or elongational experiments available in the literature. Good agreement with available theoretical predictions is also found. The proposed method is reliable, handy and does not need a calibration curve, opening an effective way to measure relaxation times of viscoelastic fluids otherwise not easily detectable by conventional techniques.

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Section: Introductionmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Rheometry-on-a-chip: measuring the relaxation time of a viscoelastic liquid through particle migration in microchannel flows

et al. 2015

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“…The liquids used in this study were rheologically characterized in both shear and elongational flows [23]. The shear viscosity was measured using a cone-plate geometry in a commercial rheometer (Haake MARS; cone angle, 2…”

Section: Rheological Properties Of the Sample Liquidsmentioning

confidence: 99%

“…This relationship is called Trouton's ratio [24]. The transition from the coiled state of the polymer to the elongated state, or the coil-stretch transition [25], occurs only for sufficiently strong flows, i.e., if the elongational ratė ε c Water 1000 ± 10 73 ± 3 1 ± 0.05 0.014 300 ppm PEO in water 1000 ± 10 61 ± 2 1.3 ± 0.05 0.021 0.4 mM Triton in water 1000 ± 10 27 ± 2 1 ± 0.05 0.037 viscosity of a polymer solution; however, an instrument known as the capillary breakup extensional rheometer (CABER) has recently become available that can be used to determine an apparent elongational viscosity [23,26]. In a CABER experiment, a droplet is placed between two plates that are subsequently separated.…”

Section: Rheological Properties Of the Sample Liquidsmentioning

confidence: 99%

Bouncing of polymeric droplets on liquid interfaces

et al. 2012

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The effect of polymers on the bouncing behavior of droplets in a highly viscous, vertically shaken silicone oil bath was investigated in this study. Droplets of a sample liquid were carefully placed on a vibrating bath that was maintained well below the threshold of Faraday waves. The bouncing threshold of the plate acceleration depended on the acceleration frequency. For pure water droplets and droplets of aqueous polymer solutions, a minimum acceleration amplitude was observed in the acceleration threshold curves as a function of frequency. The bouncing acceleration amplitude for a droplet of a dilute aqueous polymer solution was higher than the acceleration amplitude for a pure water droplet. Measurements of the center of mass trajectory and the droplet deformations showed that the controlling parameter in the bouncing process was the oscillating elongational rate of the droplet. This parameter can be directly related to the elongational viscosity of the polymeric samples. The large elongational viscosity of the polymer solution droplets suppressed large droplet deformations, resulting in less chaotic bouncing.

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Capillary breakup extensional rheometry of associative and hydrolyzed polyacrylamide polymers for oil recovery applications

Azad

Dalsania

2018

J of Applied Polymer Sci

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High molecular weight polymers used for heavy oil recovery exhibit viscoelasticity that can influence the oil recovery during chemical enhanced oil recovery. Different polymers having similar molecular weight and shear rheology may have different elongation flow behavior depending on their extensional properties. Displacing slugs are more likely to stretch than shear in tortuous porous media. Therefore, it is critical to seek an analytical tool that can characterize extensional parameters to improve polymer selection criteria. This article focuses on the extensional characterization of two polymers (hydrolyzed polyacrylamide and associative polymer) having identical shear behavior using capillary breakup extensional rheometer to explain their different porous media behavior. Maximum extensional viscosity at the critical Deborah number and Deborah number in porous media classified the associative polymer as the one having high elastic-limit. Extensional characterization results were complemented by significantly higher pressure drop, marginally increased oil recovery of associative polymer in porous media.

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Is there a relation between the relaxation time measured in CaBER experiments and the first normal stress coefficient?

Cited by 59 publications

References 28 publications

Rheometry-on-a-chip: measuring the relaxation time of a viscoelastic liquid through particle migration in microchannel flows

Rheometry-on-a-chip: measuring the relaxation time of a viscoelastic liquid through particle migration in microchannel flows

Bouncing of polymeric droplets on liquid interfaces

Capillary breakup extensional rheometry of associative and hydrolyzed polyacrylamide polymers for oil recovery applications

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