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Delegates of the national rheological societies
Society's Site Sep 2018 - Feb 2019
Appl. Rheol. 28:4 (2018) 52-56 ►
► Cite this publication as follows:
Rheological Societies: Society's Site Sep 2018 - Feb 2019, Appl. Rheol. 28 (2018) 52.
Francisco J. Galindo-Rosales
2nd Summer School on Complex Fluid-Flows in Microfluidics
Appl. Rheol. 28:4 (2018) 49-51 ►
► Cite this publication as follows:
Galindo-Rosales FJ: 2nd Summer School on Complex Fluid-Flows in Microfluidics, Appl. Rheol. 28 (2018) 49.
Catherine Taylor Nordgard
27th Nordic Rheology Conference and Course (NRC 2018)
Appl. Rheol. 28:4 (2018) 48-49 ►
► Cite this publication as follows:
Nordgard CT: 27th Nordic Rheology Conference and Course (NRC 2018), Appl. Rheol. 28 (2018) 48.
Abdulwahab S. Almusallam, T.B. Bini
Scaling Law Accomplished through Correlation of Large Amplitude Oscillatory Shear of Immiscible Polymer Blends with Jackson and Tucker Model
Appl. Rheol. 28:4 (2018) 46039 (10 pages) ►
In the current research, focus is on the comparison of Jackson and Tucker (JT) theoretical model to experimental results of large amplitude oscillatory shear (LAOS) of immiscible polymer blends. The field of rheology of immiscible polymer blends is currently very deficient in LAOS results, especially at moderate to low viscosity ratio values. In addition, most of the theoretical modeling that was carried out on LAOS of immiscible polymer blends used the small deformation theory of Maffettone and Minale. The current work adds further knowledge in the field of modeling of immiscible polymer blends by testing the predictions of the large deformation theory of Jackson and Tucker against LAOS experimental behaviour. LAOS experiments were carried out for a model immiscible blend composed of two Newtonian components (polybutadiene and polydimethylsiloxane) at viscosity ratios 1.34 and 0.39 and at volume fraction value 0.2. Data for the first, third and fifth harmonics of the sinusoidal stress response were recorded by FT-Rheological experimental set up. Validation of Jackson and Tucker model was carried out and the experimental results were compared to the JT model. Furthermore, the theoretical predictions of the JT code were compared to the experiments of Almusallam for two blends at viscosity ratio values of 0.1 and 4.4 at volume fraction value 0.21. The experimental results were plotted in terms of the scaling parameters of Reinheimer et al to test the scaling law. The Reinheimer scaling law was developed for viscosity ratio values larger than 2.5 and hence a new scaling law was developed in the current study taking into consideration the viscosity ratio values less than 2.5.► Cite this publication as follows:
Almusallam AS, Bini TB: Scaling Law Accomplished through Correlation of Large Amplitude Oscillatory Shear of Immiscible Polymer Blends with Jackson and Tucker Model, Appl. Rheol. 28 (2018) 46039.
Yikun Yang, Shuaishuai Sun, Shiyang Tang, Weihua Li, Shiwu Zhang
The Viscoelastic Properties of Gallium-Indium Alloy
Appl. Rheol. 28:4 (2018) 42903 (7 pages) ►
The viscoelastic properties of a gallium-indium alloy in the pre-yield region make it easier to understand their characteristics, particularly the varying degrees of stiffness and damping properties. These viscoelastic properties were measured with a straincontrolled rheometer, where both strain amplitude sweep mode and the angular frequency sweep mode were conducted. Three groups of experiments were carried out in the strain amplitude sweep mode. In the angular frequency sweep mode, the storage modulus G' and the loss modulus G''were investigated at the linear region, the critical region, and the non-linear region. Experimental results indicate that the gallium-indium alloy exhibited similar viscoelastic properties. The linear viscoelastic region takes place when the strain amplitude is less than the critical strain amplitude of 1%. At the critical regime, the gallium-indium alloy has the strongest relative elasticity. These results are helpful to understand the intrinsic properties of gallium-indium alloys and find their application in flexible circuits, soft robotics, self-healing, and mechanical shock absorption.► Cite this publication as follows:
Yang Y, Sun S, Tang S, Li W, Zhang S: The Viscoelastic Properties of Gallium-Indium Alloy, Appl. Rheol. 28 (2018) 42903.
S.O. Umerova, A.V. Ragulya
Temperature dependent rheology of plasticized polymer suspensions filled with ceramic nanoparticles
Appl. Rheol. 28:4 (2018) 45489 (13 pages) ►
The temperature has a significant influence on the character of flow of polymer suspensions filled with BaTiO3 nanoparticles, changing its viscosity and rheology. The viscous flow of suspensions at lower temperature from 5 to 25˚C began at higher acti- vation energy ΔEa1 and the systems were thixotropic, characterized with shear thickening at the initial stage of shearing after breaking of structural bonds between the polymer molecules. Herewith, increased shear stresses caused the enlargement of structural elements through additional flocculation by polymer bridging because of adsorption-desorption of EthCell molecule on BaTiO3 nanoparticles surface. At higher temperatures of 30 – 45 ˚C the viscous flow of suspensions began at the lower values of ΔEa2 indicating decreasing of leisure EthCell chains sufficient to form transient polymer network. Elevation of the temper-ature stipulated the predominant contribution of thermal Brownian motion to the character of flow. The mobility of macromolecules segments increased, BaTiO3 nanoparticles became to rotate, making impossible the additional structuring. Hence, the effective hydrodynamic radii of floccules remained constant. Moreover, being thixotropic at lower temperatures, the sus-pensions were characterized by the increasing of effective radii of floccules throughout the shear thickening region. In turn, rheopexic-thixotropic type of flow was characterized by the constant size of floccules along up-flow curves due to the dominant contribution of rotational Brownian motion. Thus, it is very important to control the temperature regime of processing method when exploitation of polymer suspensions.► Cite this publication as follows:
Umerova S, Ragulya A: Temperature dependent rheology of plasticized polymer suspensions filled with ceramic nanoparticles, Appl. Rheol. 28 (2018) 45489.
Salaheldin Elkatatny, Muhammad Shahzad Kamal, Fahd Alakbari, Mohamed Mahmoud
Optimizing the Rheological Properties of Water-based Drilling Fluid Using Clays and Nanoparticles for Drilling Horizontal and Multi-Lateral Wells
Appl. Rheol. 28:4 (2018) 43606 (8 pages) ►
Drilling fluid constitutes an important part of the drilling operations. Gel strength property of drilling fluids plays a key role in drilling multilateral and long horizontal reservoir sections. Losing the gel strength will accumulate drilled cuttings and as a result, sticking of the drill string. Solving this issue takes a long time and increase the total cost of the drilling operations. The objectives of this paper are to (1) determine the rheological properties of calcium carbonate water-based drilling fluid over a wide range of temperature, (2) assess the effect of adding nanoclay, bentonite, and nanosilica on the gel strength problem associated with the current field formulation of calcium carbonate water-based drilling fluids, and (3) optimize the concentration of bentonite, nanosilica, and nanoclay in the drilling fluid. The concentration of bentonite, nanoclay, and nanosilica was varied from 1 wt% to 10 wt%. Rheological properties results confirmed that the gel strength of the calcium carbonate water-based drilling fluid reached zero lb/100ft2 by increasing the temperature to 200 °F (93.33 °C). This issue was solved by adding different concentrations of bentonite, nanoclay, and nanosilica. At low bentonite concentrations (3.33 wt%), the gel strength still reduced with time. At high bentonite concentrations (10 wt%), the gel strength increased with time. The optimum concentration of bentonite was 6.66 wt%, which yielded a flat rheology profile of the gel strength. These results confirmed that the rheological properties of the water-based drilling fluid were optimized by using bentonite. Similarly, 7.5 wt% nanosilica showed the optimum performance. Nanoclay was not effective in improving the rheological properties of the calcium carbonate drilling fluid.► Cite this publication as follows:
Elkatatny S, Kamal MS, Alakbari F, Mahmoud M: Optimizing the Rheological Properties of Water-based Drilling Fluid Using Clays and Nanoparticles for Drilling Horizontal and Multi-Lateral Wells, Appl. Rheol. 28 (2018) 43606.
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