Enhanced of the R6G thermal diffusivity on aggregated small gold particles

Abstract

R6G dye with gold nanoparticles was prepared in water solution. Using a thermal lens experimental setup, the thermal diffusivity of R6G in presence of gold nanoparticles with Au different concentration was measured. The results show that, the thermal diffusivity of R6G dye mixed with gold nanoparticles increases with the increase of particle metallic concentration, enhancing the thermal diffusivity in the solution. The thermal diffusivity of the samples was studied for a constant concentration of R6G dye 0.1 g/L. The diffusivities were obtained by using the thermal lens aberrant model with lasers arranged in the mismatched mode. The characteristic time constant of the transient thermal lens was obtained by fitting the theoretical expression, for transient thermal lens, to the experimental data. UV-Vis spectroscopy and TEM were used to characterize the R6G dye gold nanoparticles.

Charge and Heat Transfer Mechanism in Directly Coupled CdSe–Metal Nanohybrids

“…It is also suggested that clustering of metal NPs can significantly affect the total heat generation and diffusion and vary the thermal diffusivity of CdSe-Au/ CdSe-Ag complexes. Most studies based on measurement of thermal diffusivity of metal nanofluids using TL studies 19,20,27,32,33 have reported enhancement of thermal diffusivity with metal nanoparticles in a dye colloidal system. Herein, we report the heat and charge transport mechanism of QD-metal nanohybrids which can be optimized using the properties of the QDs and metal.…”

Heat Transfer Enhanced in Water Containing TiO₂ Nanospheres

“…A schematic diagram of the used TL experimental setup is given in Ref [10]. From TL theory, the time evolution of the probe beam intensity I(t) at the detector is given [7]: Here I(0) is the initial intensity when t or θ is zero, P e is the excitation beam power (40 mW), A e is the absorption coefficient (cm -1 ), l 0 is the sample thickness, λ p is the probe beam wavelength (630 nm), dn/dT is the refractive index change of the sample with temperature (K -1 ), Z c = πω 2 0p /λ is the confocal distance (cm ), Z 1 is the distance of the probe beam waist to the sample, D = κ / (ρ c) is the thermal diffusivity of the sample (cm 2 s -1 ), where κ, ρ and c are the thermal conductivity (J s -1 cm -1 K -1 ), density (g cm -3 )and the specific heat of the sample (J g -1 K -1 ) respectively.…”

Estudo das propriedades termo-óticas de nanofluido de CdSe em soluções com nanobastões de Au

“…Pretende-se através do espectro de luminescência, tanto em função do tamanho do ponto quântico quanto em função da concentração do nanobastões, entender a interação resultante da combinação desses nanomaterais. Além disso, pretende-se estudar o comportamento da difusividade térmica que é conhecido por apresentar uma dependência com a concentração dos nanocompostos [4,10]. A importância deste estudo está no fato de que há muito poucos trabalhos na literatura que relataram o efeito do tamanho das nanopartículas nas propriedades de transporte térmico em nanofluídos [4].…”