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The Role of Surfactants in the Stability of NiO Nanofluids: An Experimental and DFT Study
Author(s) -
SánchezCoronilla Antonio,
Navas Javier,
Aguilar Teresa,
Martín Elisa I.,
Gallardo Juan Jesús,
GómezVillarejo Mr. Roberto,
CarrilloBerdugo Mr. Iván,
Alcántara Rodrigo,
FernándezLorenzo Concha,
MartínCalleja Joaquín
Publication year - 2017
Publication title -
chemphyschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.016
H-Index - 140
eISSN - 1439-7641
pISSN - 1439-4235
DOI - 10.1002/cphc.201601161
Subject(s) - nanofluid , non blocking i/o , pulmonary surfactant , dynamic light scattering , chemical engineering , eutectic system , materials science , hydrogen bond , chemistry , interaction energy , nanoparticle , molecule , chemical physics , nanotechnology , organic chemistry , alloy , engineering , catalysis
This study shows an analysis of the stability of nanofluids based on a eutectic mixture of diphenyl oxide and biphenyl, which is used as a heat transfer fluid (HTF) in concentrating solar energy, and NiO nanoparticles. Two surfactants are used to analyse the stability of the nanofluids: benzalkonium chloride (BAC) and 1‐octadecanethiol (ODT). From an experimental perspective, the stability is analysed by means of UV/Vis spectroscopy, particle size measurements through the dynamic light‐scattering technique, and ζ ‐potential measurements. The results show that the stability of the nanofluids improves with the use of BAC. DFT calculations are performed to understand the role played by the surfactants. The interaction of the surfactants with both the fluid and the NiO (100) surface is studied. Quantum theory of atoms in molecules (QTAIM) analysis shows that hydrogen bridge interactions favour the stability of the fluid–surfactant mixture. The more stabilising NiO–surfactant interaction involves the Ni−H interaction of the −SH and −CH 3 groups of ODT and BAC. Also, nanofluids with BAC are favoured over those with ODT, which is in agreement with experimental results. The structural and electronic effects of incorporating the surfactant onto the NiO (100) surface are shown by using electron localisation function analysis, the non‐covalent interaction index and projected density of states.