Removal of Oily Contaminants from Water by Using the Hydrophobic Ag Nanoparticles Incorporated Dopamine Modified Cellulose Foam

The presence of oil-related contaminants in water has emerged as a severe threat to the environment. The separation of these contaminants from water has become a great challenge, and extensive efforts are being made to develop suitable, environmentally friendly materials. Highly hydrophobic materials are effective in the selective separation of oil from water. In this work, silver (Ag)-incorporated, highly hydrophobic dopamine-modified cellulose sponge was prepared by functionalizing with the range of alkyl silanes. The Ag nanoparticle-incorporated dopamine provided the appropriate roughness, whereas the alkyl component provided the low surface energy that made it selective towards oil. It was found that the alkyl groups with a longer chain length were more effective in enhancing the hydrophobicity of the Ag nanoparticle-incorporated, dopamine-modified cellulose. The developed materials were characterized by Fourier transform infrared spectroscopy (FTIR), field emission-scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), elemental mapping, and contact angle goniometry. The maximum water contact angle on the functionalized surfaces was observed at 148.4°. The surface of the C18s-Ag-DA-Cell-F showed excellent selectivity towards the oily component that rapidly permeated, and water was rejected wholly. The developed material showed a separation efficiency of 96.2% for the oil/water mixture. The C18s-Ag-DA-Cell-F material showed excellent reusability. Due to their environmentally friendly nature, excellent selectivity, and good separation efficiency, the functionalized cellulose materials can be used to separate oil and water effectively.

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

Frontiers in Chemistry ◽

10.3389/fchem.2021.737550 ◽

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.

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Superhydrophobic functionalized cellulosic paper by copper hydroxide nanorods for oils purification

Scientific Reports ◽

10.1038/s41598-021-95784-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ahmed S. Belal ◽

Jehan El Nady ◽

Azza Shokry ◽

Shaker Ebrahim ◽

Moataz Soliman ◽

...

Keyword(s):

Contact Angle ◽

Filter Paper ◽

Separation Efficiency ◽

Contact Angle Measurement ◽

Angle Measurement ◽

Absorption Capacity ◽

Morphological Properties ◽

Copper Hydroxide ◽

Immersion Method ◽

Water Contact

AbstractOily water contamination has been sighted as one of the most global environmental pollution. Herein, copper hydroxide nanorods layer was constructed onto cellulosic filter paper surface cured with polydopamine, Ag nanoparticles, and Cu NPs through immersion method. This work has been aimed to produce a superhydrophobic and superoleophilic cellulosic filter paper. The structure, crystalline, and morphological properties of these modified cellulosic filter paper were investigated. Scanning electron microscope images confirmed that the modified surface was rougher compared with the pristine surface. The contact angle measurement confirmed the hydrophobic nature of these modified surfaces with a water contact angle of 169.7°. The absorption capacity was 8.2 g/g for diesel oil and the separation efficiency was higher than 99%. It was noted that the flux in the case of low viscosity solvent as n-hexane was 9663.5 Lm−2 h−1, while for the viscous oil as diesel was 1452.7 Lm−2 h−1.

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Highly Hydrophobic Cotton Fabrics Modified by Poly(methylhydrogen)siloxane and Fluorinated Olefin: Characterization and Applications

Polymers ◽

10.3390/polym12040833 ◽

2020 ◽

Vol 12 (4) ◽

pp. 833

Author(s):

Huiping Lin ◽

Qingjian Hu ◽

Tianyu Liao ◽

Xinxiang Zhang ◽

Wenbin Yang ◽

...

Keyword(s):

Cotton Fabric ◽

Separation Efficiency ◽

Cotton Fabrics ◽

Water Contact ◽

Water Separation ◽

Oh Groups ◽

Chemical Structures ◽

Stain Resistance ◽

Oil Water Separation ◽

Highly Hydrophobic

Highly hydrophobic cotton fabrics were obtained with poly(methylhydrogen)siloxane (PMHS) and a further fluorinated olefin modification. The chemical structures and microstructures of PMHS-modified cotton fabrics were characterized, and application of the resultant cotton fabrics in stain resistance and oil–water separation was demonstrated. PMHS chains with very low surface energy were grafted onto cotton fabric by the dehydrogenation reaction between –Si–H of PMHS and –OH groups of cotton fabric at room temperature. The water contact angle of PMHS-modified cotton fabric was 141.7°, which provided the modified cotton fabric with good stain resistance to waterborne pollutants. The separation efficiency of diesel from water was higher than 92% for 20 repeatable separation cycles. A further improvement in stain resistance to oil was also demonstrated by a further addition reaction of 1H,1H,2H-perfluoro-1-decene with PMHS-modified cotton fabric.

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High Stability Performance of Superhydrophobic Modified Fluorinated Graphene Films on Copper Alloy Substrates

Advances in Materials Science and Engineering ◽

10.1155/2017/6197872 ◽

2017 ◽

Vol 2017 ◽

pp. 1-8 ◽

Cited By ~ 2

Author(s):

Rafik Abbas ◽

N. Elkhoshkhany ◽

Ahmed Hefnawy ◽

Shaker Ebrahim ◽

Aya Rahal

Keyword(s):

Contact Angle ◽

Water Contact Angle ◽

Sliding Angle ◽

Water Contact ◽

Stability Performance ◽

Graphene Films ◽

Superhydrophobic Property ◽

Self Cleaning ◽

Fluorinated Graphene ◽

Highly Hydrophobic

A stable self-cleaning superhydrophobic modified fluorinated graphene surface with micro/nanostructure was successfully fabricated on copper substrates via drop coating process. Irregularly stacked island-like multilayered fluorinated graphene nanoflakes comprised the microstructure. The fabricated films exhibited outstanding superhydrophobic property with a water contact angle 167° and water sliding angle lower than 4°. The developed superhydrophobic surface showed excellent corrosion resistance with insignificant decrease of water contact angle 166° in 3.5 wt.% NaCl solution. This stable highly hydrophobic performance of the fluorinated graphene films could be useful in self-cleaning, antifogging, corrosion resistive coatings and microfluidic devices.

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Formation and characterization of superhydrophobic and alcohol-repellent nonwovens via electrohydrodynamic atomization (electrospraying)

Journal of Industrial Textiles ◽

10.1177/1528083716639061 ◽

2016 ◽

Vol 47 (1) ◽

pp. 125-146 ◽

Cited By ~ 3

Author(s):

Mehmet Dasdemir ◽

Hatice Ibili

Keyword(s):

Contact Angle ◽

Water Contact Angle ◽

Maximum Level ◽

Solution Concentration ◽

Water Mixture ◽

Water Contact ◽

Nonwoven Fabrics ◽

Alcohol Water ◽

Electrohydrodynamic Atomization ◽

Coated Fabrics

This study focuses on the development of superhydrophobic and alcohol-repellent medical nonwoven fabrics via electrohydrodynamic atomization (electrospraying). It also compares the effectiveness of electrospraying with conventional pad-dry-cure finishing application. A commercial fluorochemical finishing agent was used to prepare fluorochemical solutions at varying concentrations (0.9–9 wt%). Electrospraying characteristics of these solutions were determined with characterizing their solution properties such as viscosity, conductivity and surface tension. After the successful applications of fluorochemical solutions on nonwoven fabrics via padding and electrospraying, wet pick-up ratios and weight gains of these fabrics were calculated. Also, water and alcohol repellencies of the coated fabrics were characterized with water contact angle and alcohol contact angle measurements. According to our findings, electrospraying application yielded less chemical consumption and higher water contact angle and alcohol contact angle results than padding. Increasing solution concentration and application time for electrospraying enhanced water contact angle values, which reached a maximum level (up to 156°) and afterwards remained almost constant depending on these variables. Thus, their limits to achieve superhydrophobic surfaces were able to be determined. Electrosprayed nonwovens were also shown to be alcohol-repellent against alcohol/water mixture of 70/30 (v/v%) whereas that was 30/70 (v/v%) for padded nonwovens. The investigation of the electrosprayed surfaces revealed a very less coating on the uppermost side of surface fibres which mostly led to the enhanced water and alcohol repellencies. One of the other important outcomes of this study is that there was no significant change on the comfort properties of nonwoven fabrics after the electrospraying application.

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Highly thermally resistant hydrophobic poly(vinyl alcohol)-silica hybrid nanofibers

Journal of the Serbian Chemical Society ◽

10.2298/jsc171121032h ◽

2018 ◽

Vol 83 (7-8) ◽

pp. 885-897

Author(s):

Ugur Hulusi ◽

Burcu Oktay ◽

Atilla Gungor ◽

Nilhan Kayaman-Apohan

Keyword(s):

Contact Angle ◽

Water Contact Angle ◽

Vinyl Alcohol ◽

Sol Gel ◽

Poly Vinyl Alcohol ◽

Water Mixture ◽

Sem Images ◽

Water Contact ◽

Hybrid Nanofibers ◽

Silica Precursor

In this paper, the preparation of hydrophobic and crosslinked poly- (vinyl alcohol)/silica organic?inorganic hybrid nanofibers via the sol?gel electrospinning method is reported. Silica was produced through the acetic acid catalyzed reaction of a silica precursor consisting of dimethyldimethoxysilane (DMDMOS), methyltrimethoxysilane (MTMS), tridecafluoro-1,1,2,2-tetrahydrooctyltriethoxysilane (FAS1313; Dynasylan? F 8261) and phenyltrimethoxysilane (PTMS; Dynasylan? 9165) in a 2-propanol?water mixture. Hybrid nanofibers were obtained by electrospinning the silica precursor and an aqueous PVA solution. Chemical, structural, thermal and surface analyses were conducted by Fourier-transform infrared spectroscopy, thermogravimetric analysis, scanning electron microscopy/energy-dispersive X-ray (SEM/EDX) and water contact angle (WCA) methods, respectively. The obtained hybrid nanofibers were insoluble in aqueous solution. SEM images displayed that highly crosslinked and porous structures were obtained and the average fiber diameters of poly(vinyl alcohol) (PVA)/silica nanocomposites were around 70 nm. A nanofiber surface with a water contact angle of 130? was achieved.

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Ecological drivers of eggshell wettability in birds

Journal of The Royal Society Interface ◽

10.1098/rsif.2021.0488 ◽

2021 ◽

Vol 18 (183) ◽

Author(s):

Marie R. G. Attard ◽

James Bowen ◽

René Corado ◽

Linnea S. Hall ◽

Robert A. Dorey ◽

...

Keyword(s):

Contact Angle ◽

Extreme Environments ◽

Bird Species ◽

Microbial Colonization ◽

Initial Contact ◽

Water Contact ◽

Diverse Range ◽

External Threats ◽

Highly Hydrophobic ◽

The Relationship

Complex and at times extreme environments have pushed many bird species to develop unique eggshell surface properties to protect the embryo from external threats. Because microbes are usually transmitted into eggs by moisture, some species have evolved hydrophobic shell surfaces that resist water absorption, while also regulating heat loss and the exchange of gases. Here, we investigate the relationship between the wettability of eggshells from 441 bird species and their life-history traits. We measured the initial contact angle between sessile water droplets and the shell surface, and how far the droplet spread. Using phylogenetic comparative methods, we show that body mass, annual temperature and eggshell maculation primarily explained variance in water contact angle across eggshells. Species nesting in warm climates were more likely to exhibit highly hydrophobic eggshells than those nesting in cold climates, potentially to reduce microbial colonization. In non-passerines, immaculate eggs were found to have more hydrophobic surfaces than maculate eggshells. Droplets spread more quickly on eggshells incubated in open nests compared to domed nests, likely to decrease heat transfer from the egg. Here, we identify clear adaptations of eggshell wettability across a diverse range of nesting environments, driven by the need to retain heat and prevent microbial adhesion.

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

Journal of Chemistry ◽

10.1155/2019/7153109 ◽

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.

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Highly Hydrophobic, Homogeneous Suspension and Resin by Graft Copolymerization Modification of Cellulose Nanocrystal (CNC)

Journal of Composites Science ◽

10.3390/jcs4040186 ◽

2020 ◽

Vol 4 (4) ◽

pp. 186

Author(s):

Zhuofan Xu ◽

Shuting Peng ◽

Guofu Zhou ◽

Xuezhu Xu

Keyword(s):

Contact Angle ◽

Liquid Crystal ◽

Surface Water ◽

Graft Copolymerization ◽

Liquid Crystal Displays ◽

Cellulose Nanocrystal ◽

Hydroxyl Groups ◽

Water Contact ◽

Characterization Methods ◽

Highly Hydrophobic

Cellulose nanocrystal (CNC) is a nanoscale colloid with superior potential for coatings, liquid crystal displays, and optoelectronics. However, to date, the presence of hydrophilicity still limits its application. Multifunction via graft copolymerization modification of CNC appears to be breaking into a new direction. In this study, we used the residual hydroxyl groups on the CNC to react with 2-bromoisobu-tyryl bromide, and the initiator was therefore anchored on the CNC surface. Through atom transfer radical polymerization (ATRP), CNC was successfully grafted to azobenzene monomer, i.e., 9-[4-[2-[4-(trifluorometh) phenyl] diazenyl] phenoxy] nonayl acrylate (FAZO). After a series of characterization methods, such as FTIR, NMR and XRD, it was found that the surface water contact angle of the CNC-PFAZO prepared by the modification was as high as 134.4°, and the high hydrophilicity of this material could be maintained for up to one month, even longer.

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Fabrication of a Simultaneous Highly Transparent and Highly Hydrophobic Fibrous Films

Applied Sciences ◽

10.3390/app11125565 ◽

2021 ◽

Vol 11 (12) ◽

pp. 5565

Author(s):

Doo-Hyeb Youn ◽

Kyu-Sung Lee ◽

Sun-Kyu Jung ◽

Mangu Kang

Keyword(s):

Surface Roughness ◽

Contact Angle ◽

Water Contact Angle ◽

Electrospun Fiber ◽

Contact Angles ◽

Light Transmittance ◽

Electrospun Fibers ◽

Water Contact ◽

Aligned Fibers ◽

Highly Hydrophobic

This paper discusses the fabrication and characterization of electrospun nanofiber scaffolds made of polystyrene (PS). The scaffolds were characterized in terms of their basis material molecular weight, fiber diameter distribution, contact angles, contact angle hysteresis, and transmittance. We propose an aligned electrospun fiber scaffold using an alignment tool (alignment jig) for the fabrication of highly hydrophobic (θW > 125°) and highly transparent (T > 80.0%) films. We fabricated the alignment jig to align the electrospun fibers parallel to each other. The correlation between the water contact angles and surface roughness of the aligned electrospun fibers was investigated. We found that the water contact angle increased as the surface roughness was increased. Therefore, the hydrophobic properties of the aligned electrospun fibers were enhanced by increasing the surface roughness. With the change in the electrospinning mode to produce aligned fibers rather than randomly distributed fibers, the transmittance of the aligned electrospun fibers increased. The increase in the porous area, leading to better light transmittance in comparison to randomly distributed light scattering through the aligned electrospun fibers increased with the fibers. Through the above investigation of electrospinning parameters, we obtained the simultaneous transparent (>80%) and hydrophobic (θW > 140°) electrospun fiber scaffold. The aligned electrospun fibers of PS had a maximum transmittance of 91.8% at the electrospinning time of 10 s. The water contact angle (WCA) of the aligned electrospun fibers increased from 77° to 141° as the deposition time increased from 10 s to 40 s. The aligned fibers deposited at 40 s showed highly hydrophobic characteristics (θW > 140°).

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