Original Title:
Towards Nanofluids with excellent light radiation absorption
Languages of Item:
English
Creator:
Prouskas, C.
Evangelakis, G. A.
Koukou, M. K.
Konstantaras, John
Lymperis, K.
Vrachopoulos, Michail Gr.
Affiliation:
University of Ioannina, Department of Materials Science and Engineering, Ioannina, Greece
University of Ioannina, Department of Physics, Ioannina, Greece
Energy and Environmental Research Laboratory, National and Kapodistrian University of Athens, Psachna Campus, Evia, Greece
Abstract:
In this work, we report results on an innovative Carbon-based nanofluid suitable for increased
light radiation absorption [1,2]. The innovation resides on the interaction mechanisms of light
photons with the nanoparticles, focusing on photon trapping inside the nanoparticles, thus
taking advantage of their consecutive inelastic scattering [3] with their inner walls, until they
deliver most of their energy. Sizes and shapes of the nanoparticles are of major importance. A
quick estimation considering photons’ wavelengths to be captured, e.g. for visible spectrum
lengths around 560 nm or near IR, the nanoparticles’ cavities must have diameters around
600nm or more. Consequently, combinations of different sized nanoparticles are considered,
in addition to their sizes and shapes. A second important parameter is the phonons creation
(few μm), related with the nano-particles’ lengths. Also, these phonons must be able to
propagate. We adopted a low thermal conductivity liquid and a “thermal conduction path”
related with a percolation threshold that correlates with the optimum concentration of the
nanoparticles. The intrinsic nanoparticles’ thermal conductivity of the material is also
important. Preliminary experiments provided very promising results.
Main subject category:
Nuclear physics
Keywords:
nanofluids
radiation absorption
Notes:
Includes bibliographical references:
1. N. Goel, R. A. Taylor, T. Otanicar, A review of nanofluid-based direct absorption solar collectors: Design considerations and experiments with hybrid PV/Thermal and direct steam generation collectors, Renewable Energy 145 (2020) 903-913.
https://doi.org/10.1016/j.renene.2019.06.097.
2. R. A. Rasih, N. A. C. Sidik, S. Samion, Numerical Investigation of Direct Absorption Solar Collector using Nanofluids: A Review, IOP Conference Series: Materials Science and Engineering 469 (2019) 012059. https://doi.org/10.1088/1757-899X/469/1/012059.
3. A. K. Arora, M. Rajalakshmi, T. R. Ravindran, V. Sivasubramanian, Raman spectroscopy of optical phonon confinement in nanostructured materials, Journal of Raman Spectroscopy 38 (2007) 604-617. https://doi.org/10.1002/jrs.1684.
