Effect of water/carbon interaction strength on interfacial thermal resistance and the surrounding molecular nanolayer of CNT and graphene flake

Abstract

Heat transfer at the liquid/solid interface, especially at the nanoscale, has enormous importance in nanofluids. This study investigates liquid/solid interfacial thermal resistance and structure of the formed molecular nanolayer around a carbon-based nanoparticle. Employing non-equilibrium molecular dynamics simulation and thermal relaxation method, the nanofluid systems with different nanoparticle diameters and different surface wettability were investigated. Simulation results show that carbon nanotubes (CNTs) with a smaller diameter attract more value of the base fluid and lead to a reduced Kapitza resistance. It was found that the thickness of the nanolayer around the nanoparticle is independent of the water/carbon interaction strength. Also, the value of the Kapitza resistance decreases with increasing the interaction strength. Ultimately, a correlation was proposed for the thermal resistance of CNT/water and graphene/water nanofluids in terms of wettability intensity of nanoparticle surface.The proposed correlation in addition to fitting to simulation results can cover the physical conditions of the system.Corresponding authors: * Rajabpour@eng.ikiu.ac.ir † s_sadodin@semnan.ac.ir

Universal relation between the density and the viscosity of dispersions of nanoparticles and stabilized emulsions

“…of the order of 0.9 nm. As for the CNT -distilled-water nanofluid, molecular dynamics [64] predicts a density attaining the mean value of that of water outside a layer thickness of 1.2 nm. For a graphene -water nanofluid the same molecular dynamics study shows a value of 0.9 nm [64], confirmed by potential-energy profiles [65].…”

“…As for the CNT -distilled-water nanofluid, molecular dynamics [64] predicts a density attaining the mean value of that of water outside a layer thickness of 1.2 nm. For a graphene -water nanofluid the same molecular dynamics study shows a value of 0.9 nm [64], confirmed by potential-energy profiles [65]. Neglecting the effect of inner graphite layers, we assume that the same layer thickness would occur for the graphite -water nanodispersion, i.e.…”

Nanoconfinement Effects on the Kapitza Resistance at Water–CNT Interfaces

“…The transport of water through CNTs has drawn significant attention due to their broad range of applications such as water desalination, drug delivery, hydrogen storage, etc. − In addition to that, the higher Kapitza resistance between water and CNTs can be utilized for effectively transporting liquids at temperatures higher/lower than the ambient temperatures in future nanoscale devices for heating/cooling purposes at specific locations. Studies based on Kapitza resistance in CNT systems were mostly focused on nanocomposites and CNT-based bulk nanofluid systems. − However, studies on the nanoconfinement effect on Kapitza resistance in systems with water filled inside a CNT and molecular dynamics methods to compute the Kapitza resistance inside such cylindrical nanoconfinement systems are seldom reported to the best of the authors’ knowledge.…”

“…It shows that a better vibrational coupling between water and CNT at higher diameters, which increases the interface heat transfer, leads to a reduced Kapitza resistance. Jabbari et al 9 reported an increase in the Kapitza resistance with an increase in the CNT diameter in a water−CNT nanofluid system, where the water is outside the CNT. This can also be explained in terms of the area density factor.…”

Thermal Conductivity of Detonation Nanodiamond Hydrogels and Hydrosols by Direct Heat Flux Measurements

“…In addition, it was shown that the local thermal conductivity of the aqueous shell adjacent to the nanoparticle is approximately 50% higher than in volumetric water [ 57 ]. The calculations were made for metal particles [ 56 , 57 ] and systems containing graphene (4∙10 −8 m 2 K W −1 ) [ 55 , 58 ] and carbon nanotubes [ 59 ].…”