Surface tension of functionalized MWCNT-based nanofluids in water and commercial propylene-glycol mixture

Abstract

To cite this version:Nawal Berrada, Samah Hamze, Alexandre Desforges, Jaafar Ghanbaja, Jérôme Gleize, et al.. Surface tension of functionalized MWCNT-based nanofluids in water and commercial propylene-glycol mixture. Abstract:Nanofluids which consist of the addition of nanoparticles in a base fluid are envisaged for a large domain of applications. For many of them, the surface tension (ST) behavior of the prepared nanofluids is a key parameter to exploit their thermophysical properties. Due to their remarkable properties, carbon nanotubes (CNTs) are commonly used to develop nanofluids. However, the evolution of the ST of CNT-based nanofluids is still far from being understood and predictable.In the present work, two base fluids were used: water and a commercial mixture of propyleneglycol/water (around 40:60 wt.%). The impact of the used multi-walled CNT (MWCNT) addition, MWCNT concentration (0.001 and 0.1 wt.%) and temperature variation (273.15-333.15 K) on the density and ST evolution for the two kinds of CNT-based nanofluids is studied. The 2 chemically modified MWCNTs are assumed to bear both localized hydrophilic areas due to grafted functional groups and remaining hydrophobic surfaces. The found difference in ST behavior between the two types of nanofluids is explained in light with the involved interfaces in each nanofluid. ST evolution is found to strongly depend on the CNT surface properties.

Volumetric Properties and Surface Tension of Few-Layer Graphene Nanofluids Based on a Commercial Heat Transfer Fluid

“…The CMC is here achieved regardless of the surfactant content and can explain this result. Figure 5 shows a decrease in ST for both base fluids and nanofluids with rising temperature, as expected [23,42], for the three surfactants Triton X-100, Pluronic ® P-123 and Gum Arabic, respectively. The reduction rate of ST for Tyfocor ® LS alone in the tested temperature range is equal to 12.6%.…”

“…In the following, each reported ST value was calculated from the average of at least 10 measurements. ST of distilled water was measured in the 283.15-333.15 K temperature range [42]. The uncertainty with this equipment is low and an AAD of 1.1% was obtained between the experimental data of water and reference data in this temperature range [45].…”

“…The experimental density values were correlated to Equation (1) [38,42,49] to obtain the density values for all samples below 288.15 and above 313.15 K.…”

“…Here, nanofluids were prepared with few-layer graphene (FLG). Tyfocor ® LS, a commercial fluid which is a mixture of propylene-glycol/water (around 40:60 wt%) was used as base fluid [42,43] and three different surfactants (Triton X-100, Pluronic ® P-123 and Gum Arabic) were used to help in the dispersion and stabilization of FLG in the base fluid and to counterbalance hydrophobic attractive forces. The concentrations of nanoparticles in these nanofluids were 0.05, 0.1, 0.25 and 0.5 wt.%.…”

NePCM Based on Silver Dispersions in Poly(Ethylene Glycol) as a Stable Solution for Thermal Storage

“…Reported results were calculated from the study of at least three different drops (with a minimum of 10 recordings each). Necessary density values were experimentally obtained in this work at 288.15, 298.15, and 308.15 K while predicted values, at 318.15 and 328.15 K, were obtained by a second-order polynomial fitting based on the temperature dependence of PEG400 densities measured in Marcos et al [30] and the influence of adding PVP-capped Ag nanoparticles on this physical property determined in the present study, following a procedure similar to that used by Berrada et al [68]. Experimental uncertainty of surface tension measurements was previously estimated to be better than 1% [24].…”