Thermal and Physical Characterization of PEG Phase Change Materials Enhanced by Carbon-Based Nanoparticles

Cabaleiro, David; Hamze, Samah; Fal, Jacek; Marcos, Marco A.; Estellé, Patrice; Żyła, Gaweł

doi:10.3390/nano10061168

Cited by 51 publications

(16 citation statements)

References 105 publications

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“…The Analyzer was used to measure samples before and after boiling, while the tension meter was used for additional measurements of graphene oxide nanofluid with and without addition of surfactant (SDS). The differences in surface tension of fresh graphene oxide nanofluid determined by both devices were not statistically significant, in agreement with earlier reports [57,58].…”

Section: B Experimental Set-upssupporting

confidence: 92%

The effect of boiling in a thermosyphon on surface tension and contact angle of silica and graphene oxide nanofluids

Kujawska

Mulka

Hamze

et al. 2021

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Thermosyphons are heat transfer devices characterized by high efficiency due to simultaneous phase changes occurring in the evaporation-condensation cycle of working fluid. One of the most promising solutions to enhance their heat transfer capacity of the device is the use of nanofluids -suspensions of particles with at least one dimension below 100 nm. It was determined that nanofluid does not influence the work of thermosyphons condenser section and the focus should be put on the boiling process in the evaporator section. During boiling, nanoparticles tend to deposit on the heater's surface, what alters characteristics of this surface and near surface hydrodynamics. This changes the appearance of nanofluid, but the precise effect on how the deposition of particles affects the properties of nanofluid is unknown. Changes in surface tension and wettability affect boiling regimes (e.g. reduced surface tension reduces the size of departing bubbles and inhibits geysering), and efficiency of heat transfer through the device. Understanding of those parameters is crucial for the development of appropriate models describing heat transfer in thermosyphon working with nanofluids. The main goal of this study is to determine surface tension and contact angle of nanofluids based on silica nanoparticles and nano-sized graphene oxide flakes before and after the experimental boiling cycle in the thermosyphon. Results show that, in comparison with water, silica nanofluid (2 vol.%) is characterized by lower surface tension and contact angles on both analysed surfaces. After-use silica nanofluid exhibited noticeably higher averaged surface tension and smaller contact angles in comparison to the fresh working medium. The change was most likely due to the decreased concentration caused by the deposition of nanoparticles during the thermosyphon operation. Still, the differences between before-use and after-use samples were smaller than the measurement uncertainties. Before-use graphene oxide nanofluid already showed surface tension and contact angle similar to water due to low concentration of graphene flakes (0.1 g/L). Consequently, the properties of after-use graphene oxide fluid were also not much different from water. Additional measurements of surface tension for graphene oxide nanofluid with and without addition of sodium dodecyl sulfate surfactant allowed to differentiate the effects caused by graphene flakes and surfactant. The surfactant reduced the surface tension of the nanofluid, but the change was smaller than in case of surfactant addition to pure water.

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Section: B Experimental Set-upssupporting

confidence: 92%

The effect of boiling in a thermosyphon on surface tension and contact angle of silica and graphene oxide nanofluids

Kujawska

Mulka

Hamze

et al. 2021

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…Thermal conductivities of the base fluidethylene glycol and the elaborated nanofluids were measured at 298.15 K by means of a THW-L2 thermal conductivity device (Thermtest Inc., Canada) based on the transient short hot wire (THW) technique, that was already used in examination of nanofluids [36,37,38]. The THW-L2 apparatus allows obtaining direct thermal Experimental isobaric heat capacities for CB-EG nanofluids were determined by a quasi-isothermal temperature modulated differential scanning calorimetry technique.…”

Section: Methodsmentioning

confidence: 99%

Thermophysical profile of ethylene glycol based nanofluids containing two types of carbon black nanoparticles with different specific surface areas

Sobczak

Vallejo

Traciak

et al. 2021

Journal of Molecular Liquids

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The paper summarized results of experimental studies on thermophysical and electrical properties of ethylene glycol based nanofluids containing carbon black nanoparticles. Two types of nanoparticles differing in size and specific surface area were used to develop nanofluids. During examination the thermal conductivity, isobaric heat capacity, mass density, nanofluid-air surface tension, dynamic viscosity, refractive index and electrical conductivity were measured in strict controlled temperature 298.15 K. Obtained results indicate that the specific surface area have great influence on these fundamental properties of nanofluids developed with carbon nanoparticles.

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“…When the nanoparticles were mixed in the RT20 PCM, the thermal conductivities for Al 2 O 3 and CB were 0.234 and 0.344 W/mK, respectively. For RT25 NEPCMs, the thermal conductivities of Al 2 O 3 and CB were 0.242 and 0.323 W/mK [35]. This is very unusual, as typically nanoparticles increase the thermal conductivity; however, the Al 2 O 3 , when added, decreased the thermal conductivity of the nanosuspension.…”

Section: Increase In the Latent Heatmentioning

confidence: 96%

A Review of Thermal Property Enhancements of Low-Temperature Nano-Enhanced Phase Change Materials

Williams

Peterson

2021

Nanomaterials

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Phase change materials (PCMs) are of increasing interest due to their ability to absorb and store large amounts of thermal energy, with minimal temperature variations. In the phase-change process, these large amounts of thermal energy can be stored with a minimal change in temperature during both the solid/liquid and liquid/vapor phase transitions. As a result, these PCMs are experiencing increased use in applications such as solar energy heating or storage, building insulation, electronic cooling, food storage, and waste heat recovery. Low temperature, nano-enhanced phase change materials (NEPCM) are of particular interest, due to the recent increase in applications related to the shipment of cellular based materials and vaccines, both of which require precise temperature control for sustained periods of time. Information such as PCM and nanoparticle type, the effective goals, and manipulation of PCM thermal properties are assembled from the literature, evaluated, and discussed in detail, to provide an overview of NEPCMs and provide guidance for additional study. Current studies of NEPCMs are limited in scope, with the primary focus of a majority of recent investigations directed at increasing the thermal conductivity and reducing the charging and discharging times. Only a limited number of investigations have examined the issues related to increasing the latent heat to improve the thermal capacity or enhancing the stability to prevent sedimentation of the nanoparticles. In addition, this review examines several other important thermophysical parameters, including the thermal conductivity, phase transition temperature, rheological affects, and the chemical stability of NEPCMs. This is accomplished largely through comparing of the thermophysical properties of the base PCMs and their nano-enhanced counter parts and then evaluating the relative effectiveness of the various types of NEPCMs. Although there are exceptions, for a majority of conventional heat transfer fluids the thermal conductivity of the base PCM generally increases, and the latent heat decreases as the mass fraction of the nanoparticles increases, whereas trends in phase change temperature are often dependent upon the properties of the individual components. A number of recommendations for further study are made, including a better understanding of the stability of NEPCMs such that sedimentation is limited and thus capable of withstanding long-term thermal cycles without significant degradation of thermal properties, along with the identification of those factors that have the greatest overall impact and which PCM combinations might result in the most significant increases in latent heat.

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Thermal and Physical Characterization of PEG Phase Change Materials Enhanced by Carbon-Based Nanoparticles

Cited by 51 publications

References 105 publications

The effect of boiling in a thermosyphon on surface tension and contact angle of silica and graphene oxide nanofluids

The effect of boiling in a thermosyphon on surface tension and contact angle of silica and graphene oxide nanofluids

Thermophysical profile of ethylene glycol based nanofluids containing two types of carbon black nanoparticles with different specific surface areas

A Review of Thermal Property Enhancements of Low-Temperature Nano-Enhanced Phase Change Materials

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