TITLE:
Facile Preparation of Fluoroalkyl End-Capped Vinyltrimethoxysilane Oligomer/Sand Composites Possessing Superoleophilic/Superhydrophobic Characteristic: Application to Oil/Water Separation and Selective Removal of Fluorinated Aromatic Compounds from Aqueous Methanol Solution
AUTHORS:
Hideo Sawada, Kako Tono, Katsumi Yamashita
KEYWORDS:
Fluorinated Oligomeric Composite, Micro-Sized Ottawa Sand Particle, Superoleophilic/Superhydrophobic Property, Smooth Separation of Oil and Water, Selective Removal of Fluorinated Aromatic Compound
JOURNAL NAME:
Open Journal of Composite Materials,
Vol.12 No.1,
January
30,
2022
ABSTRACT: Fluoroalkyl
end-capped vinyltrimethoxysilane oligomer
[RF-(CH2-CHSi(OMe)3)n-RF: n = 2, 3, RF = CF(CF3)OC3F7:
RF-(VM)n-RF], was applied to the facile
preparation of the corresponding oligomer/sand (Ottawa sand: OS) composites [RF-(VM-SiO3/2)n-RF/OS]
through the sol-gel reaction of the oligomer in the presence of
micro-sized OS particles (590 - 840 μm)
under alkaline conditions at room temperature. FE-SEM (Field Emission Scanning
Electron Micrograph) images showed that the obtained composites consist of the
RF-(VM-SiO3/2)n-RF oligomeric nanoparticles and the micro-sized OS
particles. Interestingly, the RF-(VM-SiO3/2)n-RF/OS
composites thus obtained can provide
the superoleophilic/superhydrophobic characteristic on the composite
surface, applying to the separation of not only the mixture of oil/water but
also the W/O emulsion to isolate the transparent colorless oil. The fluorinated
oligomeric OS composites were also found to be applicable to the selective
removal of fluorinated aromatic compounds from an aqueous methanol solution. Especially, it was
demonstrated that the fluorinated OS composites can supply a higher efficient
and smooth separation ability for the separation of the mixture of oil and water than that of the corresponding
fluorinated micro-sized controlled silica gel (μ-SiO2) composites
(average particle size: 9.5 μm), which were prepared under similar conditions.
In addition to the separation of oil/water, the fluorinated OS composites
provided higher and more selective removal ability for the fluorinated aromatic compounds from
aqueous solutions than that of the μ-SiO2 composites.