scholarly journals Polydopamine Induced Wettability Switching of Cellulose Nanofibers/n-Dodecanethiol Composite Aerogels

2022 ◽  
Vol 2022 ◽  
pp. 1-9
Author(s):  
Runan Gao ◽  
Ying Shang ◽  
Peng Jiao ◽  
Yue Jiao ◽  
Jian Li ◽  
...  
Keyword(s):  
Cellulose Nanofibers ◽  
Absorption Capacity ◽  
Water Mixture ◽  
The Novel ◽  
Water Contact ◽  
Water Separation ◽  
Composite Aerogel ◽  
Composite Aerogels ◽  
Oil Water Separation ◽  
Oil Water

The novel wettability switchable cellulose nanofiber- (CNF-) based aerogel was conveniently prepared by polydopamine mediated composition of CNF and n-dodecanethiol. The wettability of aerogels can be controlled by adjusting the PDA and n-dodecanethiol loading content, which leads to a variation of water contact angle from 0-149°. The PDA was coated on cellulose nanofibers via hydrogen bonds and then n-dodecanethiol was anchored onto the scaffolds by Michael addition reaction, which was revealed by XPS and FTIR spectra. The composite aerogel can selectively absorb a series of oily liquids from the oil/water mixture, with the maximum absorption capacity of 68 g/g. This work presented a facile strategy to prepare wettability switchable CNF-based heterogenous aerogel and exhibited the potential of the composite aerogel for oil/water separation.

scholarly journals Complex Aerogels Generated from Nano-Polysaccharides and Its Derivatives for Oil–Water Separation

Polymers ◽  
2019 ◽  
Vol 11 (10) ◽  
pp. 1593 ◽  
Author(s):  
Hajo Yagoub ◽  
Liping Zhu ◽  
Mahmoud H. M. A. Shibraen ◽  
Ali A. Altam ◽  
Dafaalla M. D. Babiker ◽  
...  
Keyword(s):  
Guar Gum ◽  
Corn Oil ◽  
Cellulose Nanofibers ◽  
Aqueous Media ◽  
Three Dimensional ◽  
Absorption Capacity ◽  
Water Contact ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water

The complex aerogel generated from nano-polysaccharides, chitin nanocrystals (ChiNC) and TEMPO-oxidized cellulose nanofibers (TCNF), and its derivative cationic guar gum (CGG) is successfully prepared via a facile freeze-drying method with glutaraldehyde (GA) as cross-linkers. The complexation of ChiNC, TCNF, and CGG is shown to be helpful in creating a porous structure in the three-dimensional aerogel, which creates within the aerogel with large pore volume and excellent compressive properties. The ChiNC/TCNF/CGG aerogel is then modified with methyltrichlorosilane (MTCS) to obtain superhydrophobicity/superoleophilicity and used for oil–water separation. The successful modification is demonstrated through FTIR, XPS, and surface wettability studies. A water contact angle of 155° on the aerogel surface and 150° on the surface of the inside part of aerogel are obtained for the MTCS-modified ChiNC/TCNF/CGG aerogel, resulting in its effective absorption of corn oil and organic solvents (toluene, n-hexane, and trichloromethane) from both beneath and at the surface of water with excellent absorption capacity (i.e., 21.9 g/g for trichloromethane). More importantly, the modified aerogel can be used to continuously separate oil from water with the assistance of a vacuum setup and maintains a high absorption capacity after being used for 10 cycles. The as-prepared superhydrophobic/superoleophilic ChiNC/TCNF/CGG aerogel can be used as a promising absorbent material for the removal of oil from aqueous media.

scholarly journals Preparation and Characterization of Tris(trimethylsiloxy)silyl Modified Polyurethane Acrylates and Their Application in Textile Treatment

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1629
Author(s):  
Xuecheng Yu ◽  
Ying Xiong ◽  
Zhen Li ◽  
Hongding Tang
Keyword(s):  
Microphase Separation ◽  
Triethylene Glycol ◽  
Absorption Capacity ◽  
Attenuated Total Reflection ◽  
Water Mixture ◽  
Water Contact ◽  
Water Separation ◽  
Cotton Textiles ◽  
Oil Water Separation ◽  
Oil Water

Three series of silicone modified polyurethane acrylate (SPUA) prepolymers were prepared from dicyclohexylmethane-4, 4′-diisocyanate (HMDI), PPG1000, triethylene glycol (TEG), 2-hydroxyethyl acrylate (HEA), and multi-hydroxyalkyl silicone (MI-III) with tris(trimethylsiloxy)silyl propyl side groups. Their structures were confirmed by 1H NMR, 13C NMR, and Fourier transformed infrared (FTIR) analysis, and SPUA films were obtained by UV curing. The properties of films were investigated by attenuated total reflection (ATR)-FTIR, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), water contact angle (WCA), thermogravimetric analysis (TGA), differential scanning calorimeter (DSC), water and hexane resistance, and tensile testing. The results showed that the structures and dosages of MI-III could influence the polymerization properties, surface properties, water and n-hexane resistance, and thermal and tensile properties of SPUA. For instance, the surface aggregation of tris(trimethylsiloxy)silyl propyl groups (even ~2.5 wt%) could endow SPUA films with less microphase separation, good hydrophobicity, lipophilicity, thermal stability, and mechanical properties. Interestingly, obvious regular winkles appeared on the surfaces of SPUAIII films, which are characterized by relatively high WCA values. However, relatively smooth were observed on the surfaces of SPUAIII films, which also exhibit lower water absorption ratio values. Furthermore, the ordinary cotton textiles would be transformed into hydrophobic and oleophilic textiles after treating with SPUA simply, and they were used in the oil/water separation study. Among them, consistent with water and hexane resistance analysis of SPUA films, SPUAII treated cotton textiles are characterized by relatively small liquid absorption capacity (LAC) values. Thus, phenyl groups and side-chain tris(trimethylsiloxy)silyl propyl groups are helpful to improve the hydrophobicity and lipophilicity of SPUA films. SPUAII-5 (even with 5 wt% MII) treated cotton textiles could efficiently separate the oil/water mixture, such as n-hexane, cyclohexane, or methylbenzene with water. Thus, this material has great potential in the application of hydrophobic treatment, oil/water separation, and industrial sewage emissions, among others.

scholarly journals A Robust Superhydrophobic Polyurethane Sponge Loaded with Multi-Walled Carbon Nanotubes for Efficient and Selective Oil-Water Separation

Nanomaterials ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 3344
Author(s):  
De Liu ◽  
Shiying Wang ◽  
Tao Wu ◽  
Yujiang Li
Keyword(s):  
Ionic Strength ◽  
Absorptive Capacity ◽  
Large Scale ◽  
Low Cost ◽  
Absorption Capacity ◽  
Effect Of Temperature ◽  
Water Contact ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water

The influence of different coupling agents and coupling times on the wettability of a polyurethane (PU) sponge surface were optimized. Octadecyltrichlorosilane (OTS) was selected as the optimal coupling agent to prepare the superhydrophobic sponge. The superhydrophobic sponge was prepared in one step, which has the advantages of simple operation and enhanced durability. The superhydrophobic sponge was characterized by scanning electron microscopy, Teclis Tracker tensiometry, and Fourier transform infrared (FT-IR) spectrophotometry. The water contact angle increased from 64.1° to 151.3°, exhibiting ideal superhydrophobicity. Oils and organic solvents with different viscosities and densities can be rapidly and selectively absorbed by superhydrophobic sponges, with an absorption capacity of 14.99 to 86.53 times the weight of the sponge itself, without absorbing any water. Since temperature affects the viscosity and ionic strength of oil, and influences the surface wettability of the sponges, the effect of temperature and ionic strength on the oil absorption capacity of the superhydrophobic sponges was measured, and its mechanism was elucidated. The results showed that the absorptive capacity retained more than 90% of the initial absorptive capacity after repeated use for 10 times. Low-cost, durable superhydrophobic sponges show great potential for large-scale oil-water separation.

scholarly journals Preparation and Application of Superhydrophobic Copper Mesh by Chemical Etching and In-situ Growth

2021 ◽  
Vol 9 ◽  
Author(s):  
Qilei Tong ◽  
Zhenzhong Fan ◽  
Biao Wang ◽  
Qingwang Liu ◽  
Yunhe Bo ◽  
...  
Keyword(s):  
Contact Angle ◽  
Chemical Etching ◽  
Separation Efficiency ◽  
Water Mixture ◽  
Water Contact ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water ◽  
Copper Mesh

Oily sewage and floating oil in the ocean post a huge threat to the ecological environment, therefore, developing an efficient separation for oil/water mixtures is an urgent need. Currently, superhydrophobic materials exhibit excellent oil/water separation ability. In this study, a superhydrophobic copper mesh prepared by the chemical etching method and the in-situ growth method and the performance evaluation are introduced. The oxide layer on the surface of the copper mesh is first removed by pickling, and then immersed in FeCl3 solution for chemical etching to make the surface rough, stearic acid (SA) is used for in-situ growth to reduce the surface energy, a superhydrophobic oil-water separation copper mesh is obtained. The water contact angle (WCA) of the copper mesh is more than 160°. The copper mesh is chemically stable and can effectively adsorb floating oil and separate the oil-water mixture. After several oil-water separation experiments, the oil-water separation efficiency can still be above 98%. The effects of the concentration of FeCl3 and SA on the contact angle and oil-water separation efficiency are investigated, the results show that when the concentration of FeCl3 is 2% and SA is 1.5%, the WCA and oil-water separation efficiency are the largest. The research used a simple and environmentally friendly method to prepare the oil-water separation copper mesh, which has important application significance for water quality restoration.

scholarly journals Facile Fabrication of Superhydrophobic Copper- Foam and Electrospinning Polystyrene Fiber for Combinational Oil–Water Separation

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 97 ◽  
Author(s):  
Yu-Ping Zhang ◽  
Jing-Hua Yang ◽  
Ling-Li Li ◽  
Cheng-Xing Cui ◽  
Ying Li ◽  
...  
Keyword(s):  
Interaction Mechanism ◽  
Lone Pair ◽  
Absorption Capacity ◽  
Oil Absorption ◽  
Sliding Angle ◽  
Water Contact ◽  
Water Separation ◽  
Copper Foam ◽  
Oil Water Separation ◽  
Oil Water

Membrane-based metal substrates with special surface wettability have been applied widely for oil/water separation. In this work, a series of copper foams with superhydrophobicity and superoleophilicity were chemically etched using 10 mg mL−1 FeCl3/HCl solution with consequent ultrasonication, followed by the subsequent modification of four sulfhydryl compounds. A water contact angle of 158° and a sliding angle lower than 5° were achieved for the copper foam modified using 10 mM n-octadecanethiol solution in ethanol. In addition, the interaction mechanism was initially investigated, indicating the coordination between copper atoms with vacant orbital and sulfur atoms with lone pair electrons. In addition, the polymeric fibers were electrospun through the dissolution of polystyrene in a good solvent of chlorobenzene, and a nonsolvent of dimethyl sulfoxide. Oil absorption and collection over the water surface were carried out by the miniature boat made out of copper foam, a string bag of as-spun PS fibers with high oil absorption capacity, or the porous boat embedded with the as-spun fibers, respectively. The findings might provide a simple and practical combinational method for the solution of oil spill.

scholarly journals Ultralight super-hydrophobic carbon aerogels based on cellulose nanofibers/poly(vinyl alcohol)/graphene oxide (CNFs/PVA/GO) for highly effective oil–water separation

2018 ◽  
Vol 9 ◽  
pp. 508-519 ◽  
Author(s):  
Zhaoyang Xu ◽  
Huan Zhou ◽  
Sicong Tan ◽  
Xiangdong Jiang ◽  
Weibing Wu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Vinyl Alcohol ◽  
Cellulose Nanofibers ◽  
Carbon Aerogels ◽  
Poly Vinyl Alcohol ◽  
High Porosity ◽  
Water Contact ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water

With the worsening of the oil-product pollution problem, oil–water separation has attracted increased attention in recent years. In this study, a porous three-dimensional (3D) carbon aerogel based on cellulose nanofibers (CNFs), poly(vinyl alcohol) (PVA) and graphene oxide (GO) was synthesized by a facile and green approach. The resulting CNF/PVA/GO aerogels were synthesized through an environmentally friendly freeze-drying process and then carbonized to yield CNF/PVA/GO carbon aerogels with low density (18.41 mg cm−3), high porosity (98.98%), a water contact angle of 156° (super-hydrophobic) and high oil absorption capacity (97 times its own weight). The carbonization treatment of the CNF/PVA/GO aerogel not only improved the hydrophobic properties but also enhanced the adsorption capacity and specific surface area. Given the many good performance characteristics and the facile preparation process of carbon aerogels, these materials are viable candidates for use in oil–water separation and environmental protection.

scholarly journals Fabrication of durable superhydrophobic/oleophilic cotton fabric for highly efficient oil/water separation

2020 ◽  
Author(s):  
M. E. Mohamed ◽  
B. A. Abd-El-Nabey
Keyword(s):  
Cotton Fabric ◽  
Mechanical Stability ◽  
Separation Efficiency ◽  
Silicone Oil ◽  
Absorption Capacity ◽  
Water Contact ◽  
Water Separation ◽  
Coating Method ◽  
Oil Water Separation ◽  
Oil Water

Abstract In the present work, dopamine is self-polymerized on cotton fabric by a simple deep-coating method and followed by modification with an ethanolic solution of palmitic acid: a superhydrophobic/oleophilic cotton fabric was obtained. The as-prepared cotton fabric exhibits a superhydrophobic character with a water contact angle of 157o. The absorption capacity of as-prepared superhydrophobic/oleophilic cotton fabric in n-hexane, petroleum ether, and silicone oil was determined. The results show that silicone oil has the highest absorption capacity while n-hexane has the lowest value. The absorption capacity is nearly constant even after ten cycles, indicating the efficient recyclability of the as-prepared superhydrophobic/oleophilic cotton fabric for oil separation. The as-prepared superhydrophobic/oleophilic cotton fabric shows excellent separation efficiency, high flux rate, and excellent chemical and mechanical stability.

scholarly journals Fabrication of silica/PVA-co-PE nanofiber membrane for oil/water separation

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Yuanli Chen ◽  
Hui Fan ◽  
Xinlin Zha ◽  
Wenwen Wang ◽  
Yi Wu ◽  
...  
Keyword(s):  
High Efficiency ◽  
Silicone Oil ◽  
Hydroxyl Groups ◽  
Water Mixture ◽  
Silica Nanospheres ◽  
Nanofiber Membrane ◽  
Water Separation ◽  
Oil Water Separation ◽  
Silica Nanostructures ◽  
Oil Water

AbstractHigh efficiency and anti-pollution oil/water separation membrane has been widely explored and researched. There are a large number of hydroxyl groups on the surface of silica, which has good wettability and can be used for oil-water separation membranes. Hydrophilic silica nanostructures with different morphologies were synthesized by changing templates and contents of trimethylbenzene (TMB). Here, silica nanospheres with radical pores, hollow silica nanospheres and worm-like silica nanotubes were separately sprayed on the PVA-co-PE nanofiber membrane (PM). The abundance of hydroxyl groups and porous structures on PM surfaces enabled the absorption of silica nanospheres through hydrogen bonds. Compared with different silica nanostructures, it was found that the silica/PM exhibited excellent super-hydrophilicity in air and underwater “oil-hating” properties. The PM was mass-produced in our lab through melt-extrusion-phase-separation technique. Therefore, the obtained membranes not only have excellent underwater superoleophobicity but also have a low-cost production. The prepared silica/PM composites were used to separate n-hexane/water, silicone oil/water and peanut oil water mixtures via filtration. As a result, they all exhibited efficient separation of oil/water mixture through gravity-driven filtration.

scholarly journals Carbon Nanotubes and Polydopamine Modified Poly(dimethylsiloxane) Sponges for Efficient Oil–Water Separation

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2431
Author(s):  
Wen Zhang ◽  
Juanjuan Wang ◽  
Xue Han ◽  
Lele Li ◽  
Enping Liu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Large Scale ◽  
Absorption Capacity ◽  
Potential Candidate ◽  
Hard Template ◽  
Water Separation ◽  
Industrial Oil ◽  
The Matrix ◽  
Oil Water Separation ◽  
Oil Water

In this paper, effective separation of oil from both immiscible oil–water mixtures and oil-in-water (O/W) emulsions are achieved by using poly(dimethylsiloxane)-based (PDMS-based) composite sponges. A modified hard template method using citric acid monohydrate as the hard template and dissolving it in ethanol is proposed to prepare PDMS sponge composited with carbon nanotubes (CNTs) both in the matrix and the surface. The introduction of CNTs endows the composite sponge with enhanced comprehensive properties including hydrophobicity, absorption capacity, and mechanical strength than the pure PDMS. We demonstrate the successful application of CNT-PDMS composite in efficient removal of oil from immiscible oil–water mixtures within not only a bath absorption, but also continuous separation for both static and turbulent flow conditions. This notable characteristic of the CNT-PDMS sponge enables it as a potential candidate for large-scale industrial oil–water separation. Furthermore, a polydopamine (PDA) modified CNT-PDMS is developed here, which firstly realizes the separation of O/W emulsion without continuous squeezing of the sponge. The combined superhydrophilic and superoleophilic property of PDA/CNT-PDMS is assumed to be critical in the spontaneously demulsification process.

scholarly journals Gravity-Driven Separation of Oil/Water Mixture by Porous Ceramic Membranes with Desired Surface Wettability

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 457
Author(s):  
Chunlei Ren ◽  
Wufeng Chen ◽  
Chusheng Chen ◽  
Louis Winnubst ◽  
Lifeng Yan
Keyword(s):  
Porous Ceramic ◽  
Ceramic Membranes ◽  
Separation Performance ◽  
Water Mixture ◽  
Alumina Membrane ◽  
Water Separation ◽  
Alumina Membranes ◽  
Oil Water Separation ◽  
Gravity Driven ◽  
Oil Water

Porous Al2O3 membranes were prepared through a phase-inversion tape casting/sintering method. The alumina membranes were embedded with finger-like pores perpendicular to the membrane surface. Bare alumina membranes are naturally hydrophilic and underwater oleophobic, while fluoroalkylsilane (FAS)-grafted membranes are hydrophobic and oleophilic. The coupling of FAS molecules on alumina surfaces was confirmed by Thermogravimetric Analysis and X-ray Photoelectron Spectroscopy measurements. The hydrophobic membranes exhibited desired thermal stability and were super durable when exposed to air. Both membranes can be used for gravity-driven oil/water separation, which is highly cost-effective. The as-calculated separation efficiency (R) was above 99% for the FAS-grafted alumina membrane. Due to the excellent oil/water separation performance and good chemical stability, the porous ceramic membranes display potential for practical applications.

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