Thermal and rheological properties of magnetic nanofluids: Recent advances and future directions

Correlating the Dipolar Interactions Induced Magneto‐Viscoelasticity and Thermal Conductivity Enhancements in Nanomagnetic Fluids

“…The lower concentrations of MNPs do not contribute significantly to the TC enhancement, while high concentrations result in the formation of thick MNP clusters, which decrease TC. [40,70] Therefore, selecting an optimal MNP concentration is critical for maximizing the TC of NMFs. Additionally, the size of the MNPs affects the TC, with smaller MNPs having a higher TC due to their larger surface area-tovolume ratio, which enhances interparticle interactions and heat transfer.…”

“…Several models have been developed to comprehend the rheology and TC of NMFs under the influence of both static and dynamic magnetic fields. [40,[68][69][70] These models provide a close approximation of the TC, yet a precise theoretical model for NMFs is yet to be established that explains the dependence of TC with different influencing factors. A theoretical model developed by Angbo Fang for a consistent hydrodynamic theory for NMFs takes into account various attributes of actual NMFs, including strong interactions between SPM NPs, high concentration, and polydispersity.…”

“…TC enhancement in NMFs is due to the alignment of MNPs' in the applied field direction, forming a bridge for thermal energy transport via phonon and thermo‐magnetic convection. [ 40 ] Despite numerous studies, it is still ambiguous if TC gain in NMFs aligns with Maxwell's effective medium theory (EMT). [ 41 ] Numerous theories have been proposed to explain the enhanced TC of NMFs, encompassing liquid layering surrounding NPs surfaces, ballistic phonon transport, microconvection from Brownian motion, and NPs aggregation.…”

“…[ 59,65 ] The formation of chain‐like structures by MNPs along the magnetic‐field orientation is consistent with the absence of such chain configurations along the temperature gradient perpendicular to the magnetic field. [ 40 ] However, many published experimental results do not demonstrate consistency in the degree of TC enhancement, supporting the hypothesis that particle alignment in the field is responsible for NMF TC enhancement. [ 66,67 ] Thus, an appropriate model that captures particle‐particle accumulation development could be critical in predicting TC.…”

A green, robust, and versatile BN nanosheet unidirectional aerogel encapsulated phase change material for effective thermal management of electronics and solar-thermoelectric conversion

“…7 Thermal conduction technology relies on metal heat sinks or high-thermal-conductivity materials to dissipate the generated heat from one area to another. 8 However, heat that does not disappear can still lead to thermal runaway and harm operators. These problems can be avoided by heat flux manipulation strategies using phase change materials (PCMs).…”