Limits...
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.


XRD patterns of several samples: (a) O, O-di-n-cetyldithiophosphate and surface-modified Cu products with molar ratios of P to Cu of (b) 1:2; (c) 1:5; and (d) 1:10.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3211464&req=5

Figure 1: XRD patterns of several samples: (a) O, O-di-n-cetyldithiophosphate and surface-modified Cu products with molar ratios of P to Cu of (b) 1:2; (c) 1:5; and (d) 1:10.

Mentions: Depending on the concentration of the ligand (O, O-di-n-cetyldithiophosphate), different generated products of surface-modified Cu nanoparticles have been obtained. The XRD patterns of several samples are shown in Figure 1. Figure 1a gives the powder XRD pattern of the O, O-di-n-cetyldithiophosphate. Figure 1b, c, d gives those of the products with molar ratios of P to Cu of 1:2, 1:5, and 1:10, respectively. The XRD pattern with P:Cu of 1:2 (Figure 1b) or 1:10 (Figure 1d) only exhibits the peaks of ligand or Cu, respectively. The XRD pattern shown in Figure 1c gives three characteristic peaks which can be indexed as face-centered cubic (fcc) structure Cu (111), (200), and (220). No visible XRD peaks arising from the impurity phase such as CuO and Cu2O are found. It is difficult for the formation of the core of Cu in the reaction solution when the ratio of ligand is too high. However, the ligand is not sufficient to modify the Cu particles produced in the reduction process, when the ratio of the ligand is too low. Therefore, the resultant product with P:Cu molar ratio of 1:5 is appropriate for preparing nanofluids. The characterizations and studies discussed in this section are focused on this composition.


Preparation and properties of copper-oil-based nanofluids.

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

XRD patterns of several samples: (a) O, O-di-n-cetyldithiophosphate and surface-modified Cu products with molar ratios of P to Cu of (b) 1:2; (c) 1:5; and (d) 1:10.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 1: XRD patterns of several samples: (a) O, O-di-n-cetyldithiophosphate and surface-modified Cu products with molar ratios of P to Cu of (b) 1:2; (c) 1:5; and (d) 1:10.
Mentions: Depending on the concentration of the ligand (O, O-di-n-cetyldithiophosphate), different generated products of surface-modified Cu nanoparticles have been obtained. The XRD patterns of several samples are shown in Figure 1. Figure 1a gives the powder XRD pattern of the O, O-di-n-cetyldithiophosphate. Figure 1b, c, d gives those of the products with molar ratios of P to Cu of 1:2, 1:5, and 1:10, respectively. The XRD pattern with P:Cu of 1:2 (Figure 1b) or 1:10 (Figure 1d) only exhibits the peaks of ligand or Cu, respectively. The XRD pattern shown in Figure 1c gives three characteristic peaks which can be indexed as face-centered cubic (fcc) structure Cu (111), (200), and (220). No visible XRD peaks arising from the impurity phase such as CuO and Cu2O are found. It is difficult for the formation of the core of Cu in the reaction solution when the ratio of ligand is too high. However, the ligand is not sufficient to modify the Cu particles produced in the reduction process, when the ratio of the ligand is too low. Therefore, the resultant product with P:Cu molar ratio of 1:5 is appropriate for preparing nanofluids. The characterizations and studies discussed in this section are focused on this composition.

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.