Highly Thermo-Conductive Three-Dimensional Graphene Aqueous Medium

Abstract

Highly thermo-conductive aqueous medium is a crucial premise to demonstrate high-performance thermal-related applications. Graphene has the diamond comparable thermal conductivity, while the intrinsic two-dimensional reality will result in strong anisotropic thermal conductivity and wrinkles or even crumples that significantly sacrifices its inherent properties in practical applications. One strategy to overcome this is to use three-dimensional (3D) architecture of graphene. Herein, 3D graphene structure with covalent-bonding nanofins (3D-GS-CBF) is proposed, which is then used as the filler to demonstrate effective aqueous medium. The thermal conductivity and thermal conductivity enhancement efficiency of 3D-GS-CBF (0.26 vol%) aqueous medium can be as high as 2.61 W m−1 K−1 and 1300%, respectively, around six times larger than highest value of the existed aqueous mediums. Meanwhile, 3D-GS-CBF can be stable in the solution even after 6 months, addressing the instability issues of conventional graphene networks. A multiscale modeling including non-equilibrium molecular dynamics simulations and heat conduction model is applied to interpret experimental results. 3D-GS-CBF aqueous medium can largely improve the solar vapor evaporation rate (by 1.5 times) that are even comparable to the interfacial heating system; meanwhile, its cooling performance is also superior to commercial coolant in thermal management applications.

Cooling performance in a minichannel heat sink with different triangular pin-fins configurations

“…Therefore, many techniques are used to interfere with the growth of the boundary layer and enhance the cooling performance of the heat sink (Liu et al, 2022;Tian et al, 2022). Nanofluids, like threedimensional graphene nanofluid, were used as coolant media to change the fluid physical parameters, which was widely used in the cooling process of chips (Bo et al, 2020). In addition, changing the geometry, using vortex generation structure, and performing flow disruption are very effective ways (Zheng et al, 2022a).…”

High‐performance and wide relative humidity passive evaporative cooling utilizing atmospheric water

“…Moreover, the power systems for conventional cooling technologies are supplied mainly by fossil fuel‐based thermal power plants, which are the main source of anthropogenic carbon emissions. Consequently, developing high‐efficiency, environmentally friendly, and sustainable cooling strategies have become attractive for improving the working efficiency of buildings, data centers, and photovoltaics (PVs), and reducing carbon emissions, while meeting ever‐increasing energy demands 15,17–19 …”

“…Consequently, developing highefficiency, environmentally friendly, and sustainable cooling strategies have become attractive for improving the working efficiency of buildings, data centers, and photovoltaics (PVs), and reducing carbon emissions, while meeting ever-increasing energy demands. 15,[17][18][19] Evaporative cooling based on the liquid-vapor phase change of water 20,21 is a promising alternative to air conditioners owing to its super high enthalpy, that is, ~2450 J/g. For example, a technique used worldwide to cool high-temperature roads is spraying water for surface cooling.…”

A Fast-Responding Electro-Activated Shape Memory Polymer Composite with Embedded 3D Interconnected Graphene Foam

“…Compared to graphene powders, graphene foams (GFs) have higher conductivity [ 25 , 26 , 27 ], more uniform distribution, and higher porosity [ 28 ]. However, seldom have studies been reported on electro-activated SMPs embedding chemical vapor-deposited graphene foams (CVD-GFs).…”