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LIu, Dean-Mo

doi:10.1023/a:1004885432221

Cited by 177 publications

(35 citation statements)

References 11 publications

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“…Ideal structures like hexagonal close packing are unlikely to be the final packing structure for colloidal particles of a nonspherical, irregular shape. Several authors [11,[30][31][32] have arrived at a value between 0.5 and 0.55 as the maximum packing fraction in suspensions of colloidal particles and a value of 0.5 was chosen for φ m . It was also found that changing this value did not have a significant effect on the final results.…”

Section: Shear Modulus and Particle Interactionsmentioning

confidence: 99%

Shear modulus of colloidal suspensions: Comparing experiments with theory

Eriksson

Pajari

Rosenholm

2009

Journal of Colloid and Interface Science

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Section: Shear Modulus and Particle Interactionsmentioning

confidence: 99%

Shear modulus of colloidal suspensions: Comparing experiments with theory

Eriksson

Pajari

Rosenholm

2009

Journal of Colloid and Interface Science

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“…[26][27][28][29][30][31] Past work has shown that the steady shear viscosity ( , ) of nanofluids typically decreases with increasing temperature at a fixed shear rate. [32][33][34][35][36][37] Although the viscosity of suspensions has been extensively studied in the literature, 21,[37][38][39][40][41][42] there have been few studies that focus on thermal effects on the macroscopic suspension viscosity when the volume loadings pass from the dilute regime into the percolated regime. In this work, we measure the thermal conductivity and viscosity of graphite suspensions as a function of temperature and volume fraction, focusing on the percolation behavior.…”

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confidence: 99%

Viscosity and Thermal Conductivity of Stable Graphite Suspensions Near Percolation

Wang

Marconnet

et al. 2014

Nano Lett.

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Abstract:Nanofluids have received much attention due, in part, to the range of properties possible with different combinations of nanoparticles and base fluids. In this work, we measure the viscosity of suspensions of graphite particles in ethylene glycol as a function of the volume fraction, shear rate, and temperature below and above the percolation threshold. We also measure and contrast the trends observed in the viscosity with increasing volume fraction to the thermal conductivity behavior of the same suspensions: above the percolation threshold, the slope that describes the rate of thermal conductivity enhancement with concentration reduces compared to below the percolation threshold, whereas that of the viscosity enhancement * These authors contributed equally to this work. † Corresponding author: gchen2@mit.edu 2 increases. While the thermal conductivity enhancement is independent of temperature, the viscosity changes show a strong dependence on temperature and exhibit different trends with respect to the temperature at different shear rates above the percolation threshold. Interpretation of the experimental observations is provided within the framework of Stokesian dynamics simulations of the suspension microstructure, and suggest that although diffusive contributions are not important for the observed thermal conductivity enhancement, they are important for understanding the variations in the viscosity with changes of temperature and shear rate above the percolation threshold. The experimental results can be collapsed to a single master curve through calculation of a single dimensionless parameter (a Péclet number based on the rotary diffusivity of the graphite particles). The viscosity of the graphite dispersion at room temperature is measured using a controlled stress rheometer (TA Instruments AR-G2) with a coneand-plate geometry. The viscosity results show good repeatability; during repeated measurements with the same suspension the viscosity curves coincide with each other with standard deviation less than 2%. Two key trends of viscosity with shear rate are evident in Fig. 2. First, the viscosity of the graphite suspension increases as the volume fraction increases. Second, the graphite suspension exhibits non-Newtonian behavior. Specifically, the 6 viscosity decreases with increasing shear rate (i.e. the dispersion is shear thinning), and the level of shear thinning increases for higher volume fractions. This is likely due to the graphite clusters and flakes preferentially realigning themselves along the flow direction under the application of an imposed shear stress. This structural reorganization reduces particle-particle interactions and, thus, reduces the viscosity.In a previous paper, 17 some of the present authors observed that the thermal conductivity of graphite suspensions increases more rapidly with concentration below the percolation threshold than above percolation. To further study this effect, we measured the thermal conductivity of the samples (following a similar preparation proto...

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“…This behavior is considered a special case of the Herschel–Bulkey model where K and n are structure‐dependent parameters that can be determined experimentally . Figure shows the shear stress vs. shear rate dependence of the PEEK colloidal suspensions with different solids content.…”

Section: Resultsmentioning

confidence: 99%

Characterization of polyetheretherketone particle suspensions for electrophoretic deposition

Clavijo¹,

Membrives²,

Boccaccını

et al. 2014

J of Applied Polymer Sci

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Suspensions of polyetheretherketone (PEEK) using mixture of ethanol and isopropanol as solvent were prepared to carry out PEEK electrophoretic deposition (EPD). The rheological behavior and suspension structure of PEEK particles dispersed in co‐solvents were investigated over a range of pH values (1–10) and shear rates (γ = 101−3 × 102 s−1). These PEEK suspensions generally exhibited a pseudoplastic flow behavior, indicating the occurrence of particle aggregation in the liquid medium. The maximum solids fraction (ϕm) showed an estimated value of ϕm = 2.9 wt %. Using a suspension with 3 wt % PEEK concentration, PEEK coatings on stainless steel substrates were obtained by EPD at constant voltage condition. The influence of the electrolyte conductivity on PEEK EPD from ethanol–isopropanol suspensions was studied. Experimental results showed that high‐conductivity ethanol‐based suspensions yield non‐uniform deposits, while low‐conductivity suspensions resulted in uniform coatings. The difference in the deposition behavior is due to the different pH of the suspensions and the relationship of pH with suspension conductivity. pH = 8 was the optimal value for this system in terms of deposition results. The surfaces of EPD PEEK coatings were homogenous and a qualitatively good adhesion between the PEEK deposits and the substrate was confirmed. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40953.

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Cited by 177 publications

References 11 publications

Shear modulus of colloidal suspensions: Comparing experiments with theory

Shear modulus of colloidal suspensions: Comparing experiments with theory

Viscosity and Thermal Conductivity of Stable Graphite Suspensions Near Percolation

Characterization of polyetheretherketone particle suspensions for electrophoretic deposition

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