Preparation of Hydrophobic Octadecylphosphonic Acid-Coated Magnetite Nanoparticles for the Demulsification of n-Hexane-in-Water Nanoemulsions
To design more environmentally friendly, economical, and efficient demulsifiers for oily wastewater treatment, hydrophobic octadecylphosphonic acid (ODPA)-modified Fe O nanoparticles (referred to as Fe O @ODPA) were prepared by condensation of hydroxyl groups between ODPA and Fe O nanoparticles usin...
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Published in | Materials Vol. 16; no. 15; p. 5367 |
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Main Authors | , , , , |
Format | Journal Article |
Language | English |
Published |
Switzerland
MDPI AG
31.07.2023
MDPI |
Subjects | |
Online Access | Get full text |
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Summary: | To design more environmentally friendly, economical, and efficient demulsifiers for oily wastewater treatment, hydrophobic octadecylphosphonic acid (ODPA)-modified Fe
O
nanoparticles (referred to as Fe
O
@ODPA) were prepared by condensation of hydroxyl groups between ODPA and Fe
O
nanoparticles using the co-precipitation method. The prepared magnetite nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric/differential thermogravimetric (TG/DTG) analysis. The water contact angles (
) of Fe
O
@ODPA nanoparticles were more than 120°, indicating hydrophobic nature, and the diameter of the obtained spherical-shaped magnetite nanoparticles was 12-15 nm. The ODPA coating amount (
) (coating weight per gram Fe
O
) and specific surface area (
) of Fe
O
@ODPA were 0.124-0.144 g·g
and 78.65-91.01 m
·g
, respectively. To evaluate the demulsification ability, stability, and reusability, the magnetite nanoparticles were used to demulsify an n-hexane-in-water nanoemulsion. The effects of the magnetite nanoparticle dosage (
), pH value of nanoemulsion, and NaCl or CaCl
electrolytes on the demulsification efficiency (
) were investigated. The
of Fe
O
@ODPA samples was found to be higher than that of bare Fe
O
samples (S0, ST, and SN) under all
values. With the increase in
, the
of Fe
O
@ODPA samples initially increased and then approached equilibrium value at Cs = 80.0 g·L
. A maximum
of ~93% was achieved at
= 100.0 g·L
for the Fe
O
@ODPA sample S2. The pH and two electrolytes had a minor effect on
The Fe
O
@ODPA nanoparticles maintained high
even after being reused for demulsification 11 times. This indicates that the hydrophobic Fe
O
@ODPA samples can be used as an effective magnetite demulsifer for oil-in-water nanoemulsions. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 1996-1944 1996-1944 |
DOI: | 10.3390/ma16155367 |