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Enhanced Evaporation Strength through Fast Water Permeation in Graphene-Oxide Deposition.

Tong WL, Ong WJ, Chai SP, Tan MK, Hung YM - Sci Rep (2015)

Bottom Line: The capillary force attributed to the frictionless interaction between the atomically smooth, hydrophobic carbon structures and the well-ordered hydrogen bonds of water molecules is sufficiently strong to overcome the gravitational force.As a result, a thin water film is formed on the GO deposited layers, inducing filmwise evaporation which is more effective than its interfacial counterpart, appreciably enhanced the overall performance of TPCT.This study paves the way for a promising start of employing the fast water permeation property of GO in thermal applications.

View Article: PubMed Central - PubMed

Affiliation: Mechanical Engineering Discipline, School of Engineering, Monash University, 47500 Bandar Sunway, Malaysia.

ABSTRACT
The unique characteristic of fast water permeation in laminated graphene oxide (GO) sheets has facilitated the development of ultrathin and ultrafast nanofiltration membranes. Here we report the application of fast water permeation property of immersed GO deposition for enhancing the performance of a GO/water nanofluid charged two-phase closed thermosyphon (TPCT). By benchmarking its performance against a silver oxide/water nanofluid charged TPCT, the enhancement of evaporation strength is found to be essentially attributed to the fast water permeation property of GO deposition instead of the enhanced surface wettability of the deposited layer. The expansion of interlayer distance between the graphitic planes of GO deposited layer enables intercalation of bilayer water for fast water permeation. The capillary force attributed to the frictionless interaction between the atomically smooth, hydrophobic carbon structures and the well-ordered hydrogen bonds of water molecules is sufficiently strong to overcome the gravitational force. As a result, a thin water film is formed on the GO deposited layers, inducing filmwise evaporation which is more effective than its interfacial counterpart, appreciably enhanced the overall performance of TPCT. This study paves the way for a promising start of employing the fast water permeation property of GO in thermal applications.

No MeSH data available.


Variations of ΔT reduction ratio, ψ = (ΔTnf − ΔTo)/ΔTnf, of GO and SO nanofluids charged TPCTs as a function of , with the nanofluid concentration being a parameter.
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f3: Variations of ΔT reduction ratio, ψ = (ΔTnf − ΔTo)/ΔTnf, of GO and SO nanofluids charged TPCTs as a function of , with the nanofluid concentration being a parameter.

Mentions: The temperature difference, ΔT = Tevap − Tcond, manifests itself as a convenient indicator in quantifying the heat transport rate along the axial direction. In accordance with the Fourier’s law of heat conduction, under the same heat transfer rate, smaller ΔT indicates higher heat transport capability of the specimen. A low ΔT infers a low thermal resistance across the evaporator and condenser sections. We observe that ΔT of a GO-nanofluid charged TPCT is lower than that of a DI water charged TPCT. Figure 3 shows the variations of ΔT reduction ratio, ψ = (ΔTnf − ΔTo)/ΔTnf, of GO and SO nanofluids charged TPCTs as a function of , with the nanofluid concentration being a parameter. Here, ΔTo is the temperature difference of the base fluid (DI water) charged TPCT, ΔTnf is the temperature difference of the nanofluid charged TPCT, and ψ is regarded as a comparison of the change in ΔT of nanofluid charged TPCT with ΔT of a base fluid charged TPCT, indicating an enhancement in the performance of a nanofluid charged TPCT. The GO nanofluids charged TPCTs have higher ΔT reduction ratios than that of SO nanofluids charged TPCTs. At a very high concentration of SO (0.5 wt%), the performance of TPCT is comparable with that of 0.1 wt% GO nanofluid charged TPCT. This shows that the GO nanofluid TPCTs outperform the SO nanofluid ones. For GO nanofluid TPCTs charged with higher concentrations (0.05 wt%, 0.075 wt% and 0.1 wt%), we observe that ψ decreases with increasing at low and starts to increase when exceeds 6.5 W. This indicates that the GO nanofluid TPCTs perform better at a higher heat input, which will be discussed later.


Enhanced Evaporation Strength through Fast Water Permeation in Graphene-Oxide Deposition.

Tong WL, Ong WJ, Chai SP, Tan MK, Hung YM - Sci Rep (2015)

Variations of ΔT reduction ratio, ψ = (ΔTnf − ΔTo)/ΔTnf, of GO and SO nanofluids charged TPCTs as a function of , with the nanofluid concentration being a parameter.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4477327&req=5

f3: Variations of ΔT reduction ratio, ψ = (ΔTnf − ΔTo)/ΔTnf, of GO and SO nanofluids charged TPCTs as a function of , with the nanofluid concentration being a parameter.
Mentions: The temperature difference, ΔT = Tevap − Tcond, manifests itself as a convenient indicator in quantifying the heat transport rate along the axial direction. In accordance with the Fourier’s law of heat conduction, under the same heat transfer rate, smaller ΔT indicates higher heat transport capability of the specimen. A low ΔT infers a low thermal resistance across the evaporator and condenser sections. We observe that ΔT of a GO-nanofluid charged TPCT is lower than that of a DI water charged TPCT. Figure 3 shows the variations of ΔT reduction ratio, ψ = (ΔTnf − ΔTo)/ΔTnf, of GO and SO nanofluids charged TPCTs as a function of , with the nanofluid concentration being a parameter. Here, ΔTo is the temperature difference of the base fluid (DI water) charged TPCT, ΔTnf is the temperature difference of the nanofluid charged TPCT, and ψ is regarded as a comparison of the change in ΔT of nanofluid charged TPCT with ΔT of a base fluid charged TPCT, indicating an enhancement in the performance of a nanofluid charged TPCT. The GO nanofluids charged TPCTs have higher ΔT reduction ratios than that of SO nanofluids charged TPCTs. At a very high concentration of SO (0.5 wt%), the performance of TPCT is comparable with that of 0.1 wt% GO nanofluid charged TPCT. This shows that the GO nanofluid TPCTs outperform the SO nanofluid ones. For GO nanofluid TPCTs charged with higher concentrations (0.05 wt%, 0.075 wt% and 0.1 wt%), we observe that ψ decreases with increasing at low and starts to increase when exceeds 6.5 W. This indicates that the GO nanofluid TPCTs perform better at a higher heat input, which will be discussed later.

Bottom Line: The capillary force attributed to the frictionless interaction between the atomically smooth, hydrophobic carbon structures and the well-ordered hydrogen bonds of water molecules is sufficiently strong to overcome the gravitational force.As a result, a thin water film is formed on the GO deposited layers, inducing filmwise evaporation which is more effective than its interfacial counterpart, appreciably enhanced the overall performance of TPCT.This study paves the way for a promising start of employing the fast water permeation property of GO in thermal applications.

View Article: PubMed Central - PubMed

Affiliation: Mechanical Engineering Discipline, School of Engineering, Monash University, 47500 Bandar Sunway, Malaysia.

ABSTRACT
The unique characteristic of fast water permeation in laminated graphene oxide (GO) sheets has facilitated the development of ultrathin and ultrafast nanofiltration membranes. Here we report the application of fast water permeation property of immersed GO deposition for enhancing the performance of a GO/water nanofluid charged two-phase closed thermosyphon (TPCT). By benchmarking its performance against a silver oxide/water nanofluid charged TPCT, the enhancement of evaporation strength is found to be essentially attributed to the fast water permeation property of GO deposition instead of the enhanced surface wettability of the deposited layer. The expansion of interlayer distance between the graphitic planes of GO deposited layer enables intercalation of bilayer water for fast water permeation. The capillary force attributed to the frictionless interaction between the atomically smooth, hydrophobic carbon structures and the well-ordered hydrogen bonds of water molecules is sufficiently strong to overcome the gravitational force. As a result, a thin water film is formed on the GO deposited layers, inducing filmwise evaporation which is more effective than its interfacial counterpart, appreciably enhanced the overall performance of TPCT. This study paves the way for a promising start of employing the fast water permeation property of GO in thermal applications.

No MeSH data available.