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Preparation and properties of copper-oil-based nanofluids.

Li D, Xie W, Fang W - Nanoscale Res Lett (2011)

Bottom Line: The effects of adding Cu nanoparticles on the thermal oxidation stability of the fluids were investigated by measuring the hydroperoxide concentration in the Cu/kerosene nanofluids.The hydroperoxide concentrations are observed to be clearly lower in the Cu nanofluids than in their base fluids.Appropriate amounts of metal nanoparticles added in a hydrocarbon fuel can enhance the thermal oxidation stability.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry and Chemical Engineering, Weifang University, Weifang 261061, China. danli830109@163.com.

ABSTRACT
In this study, the lipophilic Cu nanoparticles were synthesized by surface modification method to improve their dispersion stability in hydrophobic organic media. The oil-based nanofluids were prepared with the lipophilic Cu nanoparticles. The transport properties, viscosity, and thermal conductivity of the nanofluids have been measured. The viscosities and thermal conductivities of the nanofluids with the surface-modified nanoparticles have higher values than the base fluids do. The composition has more significant effects on the thermal conductivity than on the viscosity. It is valuable to prepare an appropriate oil-based nanofluid for enhancing the heat-transfer capacity of a hydrophobic system. The effects of adding Cu nanoparticles on the thermal oxidation stability of the fluids were investigated by measuring the hydroperoxide concentration in the Cu/kerosene nanofluids. The hydroperoxide concentrations are observed to be clearly lower in the Cu nanofluids than in their base fluids. Appropriate amounts of metal nanoparticles added in a hydrocarbon fuel can enhance the thermal oxidation stability.

No MeSH data available.


Thermal conductivity of nanofluids: (a) Variation of thermal conductivity of nanofluids at 25°C with mass fraction of nanoparticles; (b) variation of thermal conductivity with temperature for Cu/kerosene-based nanofluids.
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Figure 6: Thermal conductivity of nanofluids: (a) Variation of thermal conductivity of nanofluids at 25°C with mass fraction of nanoparticles; (b) variation of thermal conductivity with temperature for Cu/kerosene-based nanofluids.

Mentions: Thermal conductivities of the nanofluids for different fluid-based nanofluids as a function of mass fraction of nanoparticles at 25°C are represented in Figure 6a. It can be seen that the thermal conductivity of Cu nanofluid increases with increasing mass fraction of nanoparticles for different fluid-based nanofluids. The relationship between the thermal conductivity enhancement and the mass fraction is nonlinear. The temperature effects on the enhancement of effective thermal conductivity are investigated by measuring the thermal conductivities of Cu/kerosene-based nanofluids at different temperatures, as shown in Figure 6b. It demonstrates that the thermal conductivities of the oil-based nanofluids increase clearly with the fluid temperature. The thermal conductivity of kerosene-based nanofluid increases by about 10, 13, and 14.6% with 1.0% (mass fraction) Cu nanoparticles at 25, 40, and 50°C, respectively. As the heat transfer in solid-liquid suspension occurs at the particle-fluid interface [18], an increase of the interfacial area can lead to efficient heat-transfer properties. Because the modified layers cap the copper cores and the metal surfaces do not directly contact with the base fluid, the surface-modified Cu nanoparticles are less effective than the uncoated Cu particles as far as the thermal-conductivity enhancement is concerned.


Preparation and properties of copper-oil-based nanofluids.

Li D, Xie W, Fang W - Nanoscale Res Lett (2011)

Thermal conductivity of nanofluids: (a) Variation of thermal conductivity of nanofluids at 25°C with mass fraction of nanoparticles; (b) variation of thermal conductivity with temperature for Cu/kerosene-based nanofluids.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211464&req=5

Figure 6: Thermal conductivity of nanofluids: (a) Variation of thermal conductivity of nanofluids at 25°C with mass fraction of nanoparticles; (b) variation of thermal conductivity with temperature for Cu/kerosene-based nanofluids.
Mentions: Thermal conductivities of the nanofluids for different fluid-based nanofluids as a function of mass fraction of nanoparticles at 25°C are represented in Figure 6a. It can be seen that the thermal conductivity of Cu nanofluid increases with increasing mass fraction of nanoparticles for different fluid-based nanofluids. The relationship between the thermal conductivity enhancement and the mass fraction is nonlinear. The temperature effects on the enhancement of effective thermal conductivity are investigated by measuring the thermal conductivities of Cu/kerosene-based nanofluids at different temperatures, as shown in Figure 6b. It demonstrates that the thermal conductivities of the oil-based nanofluids increase clearly with the fluid temperature. The thermal conductivity of kerosene-based nanofluid increases by about 10, 13, and 14.6% with 1.0% (mass fraction) Cu nanoparticles at 25, 40, and 50°C, respectively. As the heat transfer in solid-liquid suspension occurs at the particle-fluid interface [18], an increase of the interfacial area can lead to efficient heat-transfer properties. Because the modified layers cap the copper cores and the metal surfaces do not directly contact with the base fluid, the surface-modified Cu nanoparticles are less effective than the uncoated Cu particles as far as the thermal-conductivity enhancement is concerned.

Bottom Line: The effects of adding Cu nanoparticles on the thermal oxidation stability of the fluids were investigated by measuring the hydroperoxide concentration in the Cu/kerosene nanofluids.The hydroperoxide concentrations are observed to be clearly lower in the Cu nanofluids than in their base fluids.Appropriate amounts of metal nanoparticles added in a hydrocarbon fuel can enhance the thermal oxidation stability.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Chemistry and Chemical Engineering, Weifang University, Weifang 261061, China. danli830109@163.com.

ABSTRACT
In this study, the lipophilic Cu nanoparticles were synthesized by surface modification method to improve their dispersion stability in hydrophobic organic media. The oil-based nanofluids were prepared with the lipophilic Cu nanoparticles. The transport properties, viscosity, and thermal conductivity of the nanofluids have been measured. The viscosities and thermal conductivities of the nanofluids with the surface-modified nanoparticles have higher values than the base fluids do. The composition has more significant effects on the thermal conductivity than on the viscosity. It is valuable to prepare an appropriate oil-based nanofluid for enhancing the heat-transfer capacity of a hydrophobic system. The effects of adding Cu nanoparticles on the thermal oxidation stability of the fluids were investigated by measuring the hydroperoxide concentration in the Cu/kerosene nanofluids. The hydroperoxide concentrations are observed to be clearly lower in the Cu nanofluids than in their base fluids. Appropriate amounts of metal nanoparticles added in a hydrocarbon fuel can enhance the thermal oxidation stability.

No MeSH data available.