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.

The combination of exceptional functionalities offered by 3D graphene‐based macrostructures (GBMs) has attracted tremendous interest. 2D graphene nanosheets have a high chemical stability, high surface area and customizable porosity, which was extensively researched for a variety of applications including CO2 adsorption, water treatment, batteries, sensors, catalysis, etc. Recently, 3D GBMs have been successfully achieved through few approaches, including direct and non‐direct self‐assembly methods. In this review, the possible routes used to prepare both 2D graphene and interconnected 3D GBMs are described and analyzed regarding the involved chemistry of each 2D/3D graphene system. Improvement of the accessible surface of 3D GBMs where the interface exchanges are occurring is of great importance. A better control of the chemical mechanisms involved in the self‐assembly mechanism itself at the nanometer scale is certainly the key for a future research breakthrough regarding 3D GBMs.