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Synthesis of therminol‐graphite nanofluids and photo‐thermal conversion properties
Author(s) -
Jeong Mun Goung,
Kim Joong Bae,
Qin Caiyan,
Lee Jungchul,
Lee Bong Jae
Publication year - 2021
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.6568
Subject(s) - nanofluid , materials science , graphite , analytical chemistry (journal) , absorption (acoustics) , pulmonary surfactant , chemical engineering , nanoparticle , chromatography , chemistry , nanotechnology , composite material , engineering
Summary Therminol‐based nanofluids with graphite nanopowders (GNs) were proposed as an efficient working fluid in direct‐absorption solar collectors (DASCs), especially for elevated‐temperature applications. In this work, Therminol VP‐1/GN nanofluids (TG nanofluids) were prepared in two steps with surfactant (Triton X‐100). In the synthesis procedure, the vortex generator for coating GN with sticky surfactant ( μ = 240 mPa ⋅ s) and the ultra‐sonicator for diluting GN/Triton X‐100 mixture with Therminol VP‐1 are used. We have demonstrated excellent dispersion stability up to 4 weeks and even after heating over 100°C without any surface modification of nanoparticles. The feasibility of using the synthesized TG nanofluid as a working fluid in DASCs was experimentally demonstrated by measuring its absorption coefficient as well as by characterizing photo‐thermal conversion performance. The absorption coefficient of the TG nanofluid at 0.004 wt.% of GNs was measured to be 1.12 cm −1 , which is more than eight times enhanced from that of bare Therminol VP‐1 (ie, 0.13 cm −1 ) in the wavelengths from 350 to 1600 nm. Finally, the temperature increment of 43°C was achieved after t = 3600 s under the 5‐sun condition in the static photo‐thermal conversion experiment. Moreover, the low viscosity of TG nanofluids (only 2.2% higher than that of the bare Therminol VP‐1) supports the superiority of TG nanofluids to be applied as working fluid in DASCs.