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Enhancing Localized Evaporation through Separated Light Absorbing Centers and Scattering Centers.

Zhao D, Duan H, Yu S, Zhang Y, He J, Quan X, Tao P, Shang W, Wu J, Song C, Deng T - Sci Rep (2015)

Bottom Line: Evaporation has been considered as one of the most important phase-change processes in modern industries.Different concentrations of both the light absorbing centers and the light scattering centers were evaluated and the evaporation performance can be largely enhanced with the balance between absorbing centers and scattering centers.The findings in this study not only provide a new way to improve evaporation efficiency in plasmonic particle-based solution, but also shed lights on the design of new solar-driven localized evaporation systems.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, P.R.China.

ABSTRACT
This report investigates the enhancement of localized evaporation via separated light absorbing particles (plasmonic absorbers) and scattering particles (polystyrene nanoparticles). Evaporation has been considered as one of the most important phase-change processes in modern industries. To improve the efficiency of evaporation, one of the most feasible methods is to localize heat at the top water layer rather than heating the bulk water. In this work, the mixture of purely light absorptive plasmonic nanostructures such as gold nanoparticles and purely scattering particles (polystyrene nanoparticles) are employed to confine the incident light at the top of the solution and convert light to heat. Different concentrations of both the light absorbing centers and the light scattering centers were evaluated and the evaporation performance can be largely enhanced with the balance between absorbing centers and scattering centers. The findings in this study not only provide a new way to improve evaporation efficiency in plasmonic particle-based solution, but also shed lights on the design of new solar-driven localized evaporation systems.

No MeSH data available.


Related in: MedlinePlus

Evaporation performance of 10-nm (a) 50-nm (b) 100-nm (c) aqueous AuNP solution with different concentration under the illumination of 532-nm laser light with the power density of 35.36 W/cm2. (The insets are thermal mapping images taken from IR camera).
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f3: Evaporation performance of 10-nm (a) 50-nm (b) 100-nm (c) aqueous AuNP solution with different concentration under the illumination of 532-nm laser light with the power density of 35.36 W/cm2. (The insets are thermal mapping images taken from IR camera).

Mentions: Solutions of AuNPs of various sizes were fabricated via seed-mediated growth method27. Fig. 2a–c shows the synthesized AuNPs with expected diameters (see Methods for synthetic details). To characterize the performance of AuNP-based evaporation system, evaporation rates have been plotted as a function of the concentration of AuNPs with different sizes under the same 532-nm green laser illumination with the power density of 35.36 W/cm2. The AuNPs were stabilized by citrate, and were relatively stable with no noticeable agglomeration during the evaporation experiments (Table S1).As shown in Fig. 3, the evaporation rate of 10-nm AuNP solution rises steeply at the initial stage and reaches its steady state or plateau after its concentration falls on the saturation zone. Figure 3b,c also show similar behavior for the 50-nm and 100-nm AuNP solution. We attributed this saturation mostly to the intense light absorption of highly concentrated AuNPs at the top portion of solution and the plasmonic-induced heat is localized. To further support our hypothesis, IR thermal mappings are included in the same plot to show the temperature distribution within AuNP solutions. As shown in the inserted IR images of Fig. 3a, the temperature is uniformly distributed over the most diluted 10-nm AuNP solution and shows no sign of localization. On the contrary, after the concentration increased by thirty-fold and fell into the saturation zone, the surface temperature jumped by 24 °C and the bottom of the 10-nm AuNP solution remained cool. The thermal diffusion to bulk water was impeded and only a small portion of the overall volume of the solution was heated. The same case also occurs for the 50-nm and 100-nm AuNP solution (Fig. 3b,c).


Enhancing Localized Evaporation through Separated Light Absorbing Centers and Scattering Centers.

Zhao D, Duan H, Yu S, Zhang Y, He J, Quan X, Tao P, Shang W, Wu J, Song C, Deng T - Sci Rep (2015)

Evaporation performance of 10-nm (a) 50-nm (b) 100-nm (c) aqueous AuNP solution with different concentration under the illumination of 532-nm laser light with the power density of 35.36 W/cm2. (The insets are thermal mapping images taken from IR camera).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4660318&req=5

f3: Evaporation performance of 10-nm (a) 50-nm (b) 100-nm (c) aqueous AuNP solution with different concentration under the illumination of 532-nm laser light with the power density of 35.36 W/cm2. (The insets are thermal mapping images taken from IR camera).
Mentions: Solutions of AuNPs of various sizes were fabricated via seed-mediated growth method27. Fig. 2a–c shows the synthesized AuNPs with expected diameters (see Methods for synthetic details). To characterize the performance of AuNP-based evaporation system, evaporation rates have been plotted as a function of the concentration of AuNPs with different sizes under the same 532-nm green laser illumination with the power density of 35.36 W/cm2. The AuNPs were stabilized by citrate, and were relatively stable with no noticeable agglomeration during the evaporation experiments (Table S1).As shown in Fig. 3, the evaporation rate of 10-nm AuNP solution rises steeply at the initial stage and reaches its steady state or plateau after its concentration falls on the saturation zone. Figure 3b,c also show similar behavior for the 50-nm and 100-nm AuNP solution. We attributed this saturation mostly to the intense light absorption of highly concentrated AuNPs at the top portion of solution and the plasmonic-induced heat is localized. To further support our hypothesis, IR thermal mappings are included in the same plot to show the temperature distribution within AuNP solutions. As shown in the inserted IR images of Fig. 3a, the temperature is uniformly distributed over the most diluted 10-nm AuNP solution and shows no sign of localization. On the contrary, after the concentration increased by thirty-fold and fell into the saturation zone, the surface temperature jumped by 24 °C and the bottom of the 10-nm AuNP solution remained cool. The thermal diffusion to bulk water was impeded and only a small portion of the overall volume of the solution was heated. The same case also occurs for the 50-nm and 100-nm AuNP solution (Fig. 3b,c).

Bottom Line: Evaporation has been considered as one of the most important phase-change processes in modern industries.Different concentrations of both the light absorbing centers and the light scattering centers were evaluated and the evaporation performance can be largely enhanced with the balance between absorbing centers and scattering centers.The findings in this study not only provide a new way to improve evaporation efficiency in plasmonic particle-based solution, but also shed lights on the design of new solar-driven localized evaporation systems.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, 800 Dong Chuan Road, Shanghai 200240, P.R.China.

ABSTRACT
This report investigates the enhancement of localized evaporation via separated light absorbing particles (plasmonic absorbers) and scattering particles (polystyrene nanoparticles). Evaporation has been considered as one of the most important phase-change processes in modern industries. To improve the efficiency of evaporation, one of the most feasible methods is to localize heat at the top water layer rather than heating the bulk water. In this work, the mixture of purely light absorptive plasmonic nanostructures such as gold nanoparticles and purely scattering particles (polystyrene nanoparticles) are employed to confine the incident light at the top of the solution and convert light to heat. Different concentrations of both the light absorbing centers and the light scattering centers were evaluated and the evaporation performance can be largely enhanced with the balance between absorbing centers and scattering centers. The findings in this study not only provide a new way to improve evaporation efficiency in plasmonic particle-based solution, but also shed lights on the design of new solar-driven localized evaporation systems.

No MeSH data available.


Related in: MedlinePlus