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The Development of Superhydrophobic PVA Sponge, Using HDTMS and HMDS, for the Separation of an Oil–Water Mixture with a Very High Separation Efficiency

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Anup Kumar Bairagi
Anup Kumar Bairagi
Anup Kumar Bairagi
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Soumya Sanjeeb Mohapatra
Soumya Sanjeeb Mohapatra
Soumya Sanjeeb Mohapatra
  • This person is not on ResearchGate, or hasn't claimed this research yet.
Abanti Sahoo at National Institute of Technology Rourkela
Abanti Sahoo
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Abstract and Figures

The marine natural ecosystem suffers substantial damage from industrial oily wastes. Various mechanisms such as adsorption, aeration, sedimentation, screening, disinfection, and chemical oxidation have been proposed in the literature to treat oily waste water. The suggested approach to the aforementioned treatment comes at a significant expense. Therefore, in this work, a low-cost, recyclable sponge that is kind to the environment and has a high level of super hydrophobicity and oleophilic properties was designed to extract oil from wastewater. Titanium dioxide, carbon soot, and hexadecytrimethoxysilane (HDTMS) were employed as the coating materials to create superhydrophobic surfaces. For the post-coating analysis, the contact angle of oil and water, FTIR of coatings, and SEM of different coated PVA sponges were studied. The oil absorption capacity and changes in the contact angles between oil and water droplets over time were both examined in order to assess the coatings’ effectiveness. With a 151° water contact angle, HDTMS-coated sponge proven to be more effective at separating oil from water. According to the impact mapping results, a hydrophobic surface initially achieves no slip condition before slip condition is recognized. The relationship between viscous force and capillary force (VF/CF) is seen as the defining factors for super-hydrophobic properties, according to the examination of droplet dynamics. The VF/CF ratio must be lower than 2.9 × 10⁻⁴ in order to achieve superhydrophobicity features. Additionally, the HDTMS sponge’s 99.9% oil absorption capacity was discovered. Moreover, the impact of oil characteristics on the capacity for absorption has been studied. The mechanism and thermal stability have also been covered in addition to the aforementioned.
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Vol.: (0123456789)
1 3
Water Air Soil Pollut (2023) 234:298
https://doi.org/10.1007/s11270-023-06292-x
The Development ofSuperhydrophobic PVA Sponge, Using
HDTMS andHMDS, fortheSeparation ofanOil–Water
Mixture withaVery High Separation Efficiency
The VF/CF ratio must be lower than 2.9 × 10−4 in
order to achieve superhydrophobicity features. Addi-
tionally, the HDTMS sponge’s 99.9% oil absorption
capacity was discovered. Moreover, the impact of oil
characteristics on the capacity for absorption has been
studied. The mechanism and thermal stability have
also been covered in addition to the aforementioned.
Keywords Contact angle· Superhydrophobicity·
Oil–water separation· Thermal stability
Nomenclature
Subscripts
Mf
Weights of the sponge after oil
absorption
Mi
Weights of the sponge before oil
absorption
Q Absorption capacity gm/gm
η Oil–water separation efficiency
CF Capillary force, N
VF Viscous force, N
Acronyms CS Carbon soot
PVA Polyvinyl alcohol
HDTMS Hexadecyltrimethoxysilane
HMDS Hexamethyldisilazane
FTIR Fourier transform infrared
spectroscopy
SEM Scanning electron microscope
1 Introduction
Wastewater from chemical industries contains heavy
metals, organic and inorganic materials, fertilizer,
Abstract The marine natural ecosystem suffers sub-
stantial damage from industrial oily wastes. Various
mechanisms such as adsorption, aeration, sedimen-
tation, screening, disinfection, and chemical oxida-
tion have been proposed in the literature to treat oily
waste water. The suggested approach to the afore-
mentioned treatment comes at a significant expense.
Therefore, in this work, a low-cost, recyclable sponge
that is kind to the environment and has a high level
of super hydrophobicity and oleophilic properties was
designed to extract oil from wastewater. Titanium
dioxide, carbon soot, and hexadecytrimethoxysilane
(HDTMS) were employed as the coating materials
to create superhydrophobic surfaces. For the post-
coating analysis, the contact angle of oil and water,
FTIR of coatings, and SEM of different coated PVA
sponges were studied. The oil absorption capacity
and changes in the contact angles between oil and
water droplets over time were both examined in order
to assess the coatings’ effectiveness. With a 151°
water contact angle, HDTMS-coated sponge proven
to be more effective at separating oil from water.
According to the impact mapping results, a hydropho-
bic surface initially achieves no slip condition before
slip condition is recognized. The relationship between
viscous force and capillary force (VF/CF) is seen as
the defining factors for super-hydrophobic properties,
according to the examination of droplet dynamics.
A.K.Bairagi· S.S.Mohapatra(*)· A.Sahoo
Department ofChemical Engineering, NIT Rourkela,
Rourkela769008, India
e-mail: mohapatras@nitrkl.ac.in
AnupKumarBairagi·SoumyaSanjeebMohapatra · AbantiSahoo
Received: 9 January 2023 / Accepted: 4 April 2023 / Published online: 26 April 2023
© The Author(s), under exclusive licence to Springer Nature Switzerland AG 2023
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... This is because the functional groups on the GO surface can react with the Si-OH groups hydrolyzing from the HMDS by forming the hydrogen or -C-O-Si(CH 3 ) 3 covalent bonds [59,60]. Results are also confirmed by the XPS spectra, where the intensity of peak at 286.0 eV corresponding to the C-O group is significantly decreased in the C1s XPS spectra of PFS@GO@HMDS compared with that of PFS@GO (Figs. 2i and S2) [61][62][63]. The possible chemical bonding mechanism among plant fiber, GO, and HMDS is schematically shown in Fig. 1b. ...
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