A facile one-step spray-coating process for the fabrication of a superhydrophobic attapulgite coated mesh for use in oil/water separation

Abstract

Oil/water separation is a worldwide problem due to the increasing industrial oily waste water and the frequent oil spill accidents. Here, we first demonstrate superhydrophobic attapulgite coated mesh films for gravity driven oil water separation, which was fabricated by a facile one-step spray-coating process. The as-prepared attapulgite coated mesh films show both superhydrophobic and superoleophilic properties simultaneously with a high water contact angle of 155 ± 1° and an oil contact angle of 0°. Thus, it can be used to separate a series of oil/water mixtures like kerosene, chloroform, petroleum ether, etc. with the separation efficiency up to 97 % for the kerosene-water mixture. In addition, the as-prepared coated mesh still maintained separation efficiency above 94% and stable recyclability after 40 separation cycles with the surface morphology of the attapulgite coated mesh nearly unchanged. Besides, the separation mechanism for the oil/water mixture was elaborated by interpreting the different states of water droplet on the surface before and during separation, which has been discussed scarcely. Furthermore, the 2 as-prepared attapulgite coated mesh could keep superhydrophobic property with various harsh conditions not only for pure water but for corrosive solutions under acidic, alkaline and corrosive salt solutions, which shows attractive potential for practical oil-water separation in industry and everyday life.

A facile one-step preparation method of recyclable superhydrophobic polypropylene membrane for oil–water separation

“…In order to get high flux for practical application in oil-water separation these superhydrophobic materials coated metallic mesh and textile sheets were also developed, such as the carbon nanotubes grown on stainless steel mesh by thermal chemical vapor deposition with a diffusion barrier of Al 2 O 3 film 10 , 1-hexadecanethiol grafted copper mesh through solution-immersion in nitric acid solution and sequential modification with 1hexadecanethiol 11 , teflon coated stainless steel mesh by spray-anddry method 12 , waste-potato-residue/candle-soot/silica/attapulgite coated meshes by one-step spray-coating method [13][14][15] , polyacrylamide hydrogel coated stainless steel mesh from a photoinitiated polymerization process with acrylamide, N , N'methylene bisacrylamide, 2,2'-diethoxyacetophenone, and polyacrylamide 16 , a block [poly(2-vinylpyridine)-bpolydimethylsiloxane] copolymer grafted non-woven textiles and polyurethane sponges by a block copolymer-grafting strategy 17 , surface coating of polyester textile via chemical vapour deposition of trichloromethylsilane 18 and electrospinning, dip-coating and spincoating of heptadecafluorodecyl polyhedral oligomeric silsequioxane + cross-linked poly(ethylene glycol) diacrylate, or poly (methylmethacrylate) onto stainless steel wire meshes. 19,20 However, all these above fabrication procedures are either costly or complicated.…”

Modification of wetting property of Inconel 718 surface by nanosecond laser texturing

“…Based on the basis of such principle, a variety of methods have been employed to obtain thermodynamically stable hydrophobic or even superhydrophobic surfaces through controlling both of the surface chemical components and surface morphological structures, such as sol-gel coating [25][26], electrochemical deposition [27], chemical etching [28], laser surface texturing [29][30][31] and spray-coating [32]. Among these options, laser treatment is a promising technique to create superhydrophobic surfaces [33].…”

Purification of oily seawater/wastewater using superhydrophobic nano-silica coated mesh and sponge

“…Variants of this method, using various coating materials on the mesh, such as carboxylic acid [5], thiol [9], ZnO [10], silane [11], or Cu 2 O film [12] have been extensively studied to achieve superhydrophobicity, and have shown effective oil-water separation. Even though the high efficient separation of different oils, from hexane to heavy mineral oil, has been achieved, the separation of oil from oily seawater or wastewater with high separation efficiency has yet to be studied [13][14][15]. The unusual wettability of as-made superhydrophobic substrates may render them unstable in salt solutions [9].…”