scholarly journals Effects of Surface Microstructures on Superhydrophobic Properties and Oil-Water Separation Efficiency

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 69 ◽  
Author(s):  
Yangyang Chen ◽  
Shengke Yang ◽  
Qian Zhang ◽  
Dan Zhang ◽  
Chunyan Yang ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Contact Angles ◽  
Water Contact ◽  
Water Separation ◽  
Cone Morphology ◽  
Truncated Cone ◽  
Oil Water Separation ◽  
Receding Contact ◽  
Oil Water ◽  
Pressure Resistance

In order to explore the effects of microstructures of membranes on superhydrophobic properties, it is critical, though, challenging, to study microstructures with different morphologies. In this work, a combination of chemical etching and oxidation was used and some copper meshes were selected for grinding. Two superhydrophobic morphologies could be successfully prepared for oil-water separation: a parabolic morphology and a truncated cone morphology. The surface morphology, chemical composition, and wettability were characterized. The results indicated that the water contact angle and the advancing and receding contact angles of the parabolic morphology were 153.6°, 154.6 ± 1.1°, and 151.5 ± 1.8°, respectively. The water contact angle and the advancing and receding contact angles of the truncated cone morphology were 121.8°, 122.7 ± 1.6°, and 119.6 ± 2.7°, respectively. The separation efficiency of the parabolic morphology for different oil-water mixtures was 97.5%, 97.2%, and 91%. The separation efficiency of the truncated cone morphology was 93.2%, 92%, and 89%. In addition, the values of the deepest heights of pressure resistance of the parabolic and truncated cone morphologies were 21.4 cm of water and 19.6 cm of water, respectively. This shows that the parabolic morphology had good separation efficiency, pressure resistance, and superhydrophobic ability compared with the truncated cone morphology. It illustrates that microstructure is one of the main factors affecting superhydrophobic properties.

scholarly journals Facile Fabrication of Magnetic, Durable and Superhydrophobic Cotton for Efficient Oil/Water Separation

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 442 ◽  
Author(s):  
Mingguang Yu ◽  
Qing Wang ◽  
Wenxin Yang ◽  
Yonghang Xu ◽  
Min Zhang ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Water Repellency ◽  
Cotton Fabrics ◽  
Ammonia Solution ◽  
Hot Water ◽  
Water Contact ◽  
Water Separation ◽  
Efficient Strategy ◽  
Oil Water Separation ◽  
Oil Water

In this paper, we present a facile and efficient strategy for the fabrication of magnetic, durable, and superhydrophobic cotton for oil/water separation. The superhydrophobic cotton functionalized with Fe3O4 magnetic nanoparticles was prepared via the in situ coprecipitation of Fe2+/Fe3+ ions under ammonia solution on cotton fabrics using polyvinylpyrrolidone (PVP) as a coupling agent and hydrophobic treatment with tridecafluorooctyl triethoxysilane (FAS) in sequence. The as-prepared cotton demonstrated excellent superhydrophobicity with a water contact angle of 155.6° ± 1.2° and good magnetic responsiveness. Under the control of the external magnetic field, the cotton fabrics could be easily controlled to absorb the oil from water as oil absorbents, showing high oil/water separation efficiency, even in hot water. Moreover, the cotton demonstrated remarkable mechanical durable properties, being strongly friction-resistant against sandpaper and finger wipe, while maintaining its water repellency. This study developed a novel and efficient strategy for the construction of magnetic, durable, and superhydrophobic biomass-based adsorbent for oil/water separation, which can be easily scaled up for practical oil absorption.

scholarly journals Preparation of Parabolic Superhydrophobic Material for Oil-Water Separation

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1914 ◽  
Author(s):  
Xiaoying Qiao ◽  
Chunyan Yang ◽  
Qian Zhang ◽  
Shengke Yang ◽  
Yangyang Chen ◽  
...  
Keyword(s):  
Contact Angle ◽  
Carbon Tetrachloride ◽  
Separation Efficiency ◽  
Contact Angles ◽  
Engine Oil ◽  
Water Droplets ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water ◽  
Copper Mesh

In order to prepare parabolic superhydrophobic materials, copper meshes were used as the substrate and ultrasonic etching and oxidative corrosion were carried out with FeCl3 solution and H2O2 solution, respectively, and then the surface was modified with stearic acid (SA). The topological structure and surface wettability of the prepared mesh were characterized by fluorescence microscope, scanning electron microscopy and contact angle measurement. Finally, the as-prepared copper meshes were applied to oil-water separation. The results showed that the micro-nano-mastoid structure on the surface of the copper mesh was flaky bulges, forming a rough structure similar to a paraboloid. When the oxidative corrosion time of H2O2 was 1 min, it is more beneficial to increase the hydrophobicity of the surface of the copper mesh and increase the contact angle of water droplets on the surface of the membrane. Additionally, based on superhydrophobic materials of the parabolic copper mesh, the static contact angles of the water droplets, engine oil and carbon tetrachloride with the surface were approximately 153.6°, 5° and 0.1°, respectively and the sliding angle of the water droplets with the surface were approximately 4.9°. The parabolic membrane was applied to discuss the separation efficiency of different oils with deionized water and the separation efficiency was obtained as benzene > carbon tetrachloride > oil > machine oil. Therefore, based on the research, the parabolic superhydrophobic material has good efficiency of oil-water separation.

Facile fabrication of superhydrophobic filter paper with improved durability and water repellency

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Lizheng Sha ◽  
Chao Ma ◽  
Huifang Zhao ◽  
Supeng Qiu ◽  
Zhongyu Yan ◽  
...  
Keyword(s):  
Filter Paper ◽  
Separation Efficiency ◽  
Cellulose Nanofibrils ◽  
Water Repellency ◽  
Step Method ◽  
Water Contact ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water ◽  
Self Cleaning

Abstract Superhydrophobic surfaces have high potential in self-cleaning and oil-water separation applications. We developed a three-step method for the preparation of superhydrophobic filter paper. It involved citric acid (CA) pretreatment to activate cellulose fibers, coating with cellulose nanofibrils/functionalized silica (CNFs/m-SiO2) slurry to increase surface roughness, and grafting of hexadecyltrimethoxysilane (HDTMS) to enhance water resistance. The water contact angle (WCA) and siding angle (SA) of the prepared filter paper reached 151.5° and 7.5°, respectively. The results showed that, compared to the coated filter paper without the added CNFs, the coated paper with CNFs had higher retention of m-SiO2, thus roughness required for superhydrophobic surface was achieved. Further test under frequent abrasion and acid or alkali conditions showed that CA pretreatment improved the durability of superhydrophobic filter paper due to chemical crosslinking between the modified substrate and m-SiO2. Besides, the prepared superhydrophobic filter paper had outstanding self-cleaning property and high oil-water separation efficiency for various oil-water mixtures. Therefore, it is expected to be used for the treatment of oily wastewater.

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 Synthesis of a Superhydrophobic Polyvinyl Alcohol Sponge Using Water as the Only Solvent for Continuous Oil-Water Separation

2019 ◽  
Vol 2019 ◽  
pp. 1-8
Author(s):  
Junyong Chen ◽  
Junhui Xiang ◽  
Xian Yue ◽  
Huaxin Li ◽  
Xianbo Yu
Keyword(s):  
Contact Angle ◽  
Polyvinyl Alcohol ◽  
Separation Efficiency ◽  
Water Contact ◽  
Water Separation ◽  
Long Term Stability ◽  
Static Water ◽  
Oil Water Separation ◽  
Oil Water

Few cases of hydrophobic materials synthesized in water have been reported. In this work, water, as the only solvent, is used to prepare a superhydrophobic sponge via a facile and environment-friendly route. The as-prepared sponge, namely silylated polyvinyl alcohol (PVA) sponge, exhibits superhydrophobic and superoleophilic characters. It has the static water contact angle (WCA) of 152 ± 1 and the static oil contact angle (OCA) of 0°, which can lead to excellent selectivity for oil-water separation. Besides, the methyltriethoxysilane (MTES) can form a stable mixed structure with the PVA skeleton, resulting in the rare shedding of polymethylsiloxane nanoparticles and the long-term stability for oil-water separation. Furthermore, the silylated sponge shows a high separation efficiency (>99.6%), removing oil up to 6200∼14000 times of its own mass. The findings demonstrated that the silylated superhydrophobic sponge can be a promising candidate in water treatment application.

scholarly journals Environment-Friendly and Two-Component Method for Fabrication of Highly Hydrophobic Wood Using Poly(methylhydrogen)siloxane

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 124
Author(s):  
Jie Gao ◽  
Wensheng Lin ◽  
Shumin Lin ◽  
Xinxiang Zhang ◽  
Wenbin Yang ◽  
...  
Keyword(s):  
Cross Sections ◽  
Contact Angles ◽  
Practical Application ◽  
Water Contact ◽  
Water Separation ◽  
Environment Friendly ◽  
Two Component ◽  
Oil Water Separation ◽  
Oil Water ◽  
Highly Hydrophobic

Practical application of wood remains a great challenge because of its highly hydrophilic property. In this work, highly hydrophobic wood was produced using an environment-friendly and two-component package method. Poly(methylhydrogen)siloxane (PMHS) and inhibitor played the key role in the hydrophobicity of wood and the assembly process. The two-component package mechanism was discussed in detail. As a result, the water contact angles of the modified wood surface for the radial and cross sections were 139.5° and 152.9°, respectively, which provided the resultant wood high hydrophobicity and dimensional stability. The two-component package method afforded the wood good anti-fouling property and UV-resistance. In addition, the two-component package method could also be applied in functionalization of filter paper for oil/water separation.

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 Dodecyl Mercaptan Functionalized Copper Mesh for Water Repellence and Oil-water Separation

2021 ◽  
Vol 18 (4) ◽  
pp. 887-899
Author(s):  
Yanling Tian ◽  
Jiekai Feng ◽  
Zexin Cai ◽  
Jiaqi Chao ◽  
Dawei Zhang ◽  
...  
Keyword(s):  
Separation Efficiency ◽  
Synthesis Process ◽  
Water Separation ◽  
Oil Water Separation ◽  
One Step ◽  
Oil Water ◽  
Water Repellence ◽  
Copper Mesh ◽  
Dodecyl Mercaptan

AbstractReckless discharge of industrial wastewater and domestic sewage as well as frequent leakage of crude oil have caused serious environmental problems and posed severe threat to human survival. Various nature inspired superhy-drophobic surfaces have been successfully applied in oily water remediation. However, further improvements are still urgently needed for practical application in terms of facile synthesis process and long-term durability towards harsh environment. Herein, we propose a simple one-step dodecyl mercaptan functionalization method to fabricate Super-hydrophobic-Superoleophilic Copper Mesh (SSCM). The prepared SSCM possesses excellent water repellence and oil affinity, enabling it to successfully separate various oil-water mixtures with high separation efficiency (e.g., > 99% for hexadecane-water mixture). The SSCM retains high separating ability when hot water and strong corrosive aqueous solutions are used to simulate oil-water mixtures, indicating remarkable chemical durability of the dodecyl mercaptan functionalized copper mesh. Additionally, the efficiency can be well maintained during 50 cycles of separation, and the water repellence is even stable after storage in air for 120 days, demonstrating the reusability and long-term stability of the SSCM. Furthermore, the functionalized mesh also shows good mechanical robustness towards abrasion by sandpaper, and oil-water separation efficiency of > 96% can be obtained after 10 cycles of abrasion. The reported one-step dodecyl mercaptan functionalization could be a simple method for increasing the water repellence of copper mesh, and thereby be a great candidate for treating large-scale oily wastewater in harsh environments.

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.

Design and fabrication of polydopamine based superhydrophobic fabrics for efficient oil-water separation

Soft Matter ◽  
2021 ◽  
Author(s):  
Jixi Zhang ◽  
Ligui Zhang ◽  
Xiao Gong
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Sol Gel ◽  
High Water ◽  
Water Contact ◽  
Water Separation ◽  
Oil Water Separation ◽  
Oil Water ◽  
Fabric Surface

In this work, we prepare a PDMS-SiO2-PDA@fabric with high water contact angle (WCA=155o). Combining dopamine self-polymerization and sol-gel method, SiO2 is in situ grown on a PDA-modified fabric surface to...

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