A free-standing porous silicon-type gel sponge with superhydrophobicity and oleophobicity

Abstract

Porous and spongy superhydrophobic silicon-type gels monoliths have been fabricated by a facile method. The gel can be turned oleophobic after modification with fluorosilane. The as-prepared free-standing silicon-type gels demonstrate superhydrophobicity and oleophobicity not only on the upper surface but also throughout the whole monolith. Importantly, the as-prepared amphiphobic silicon-type gels have remarkable chemical stability even in corrosive solutions over a wide range of pH conditions. Moreover, the silicon-type gel monoliths also have stable amphiphobic properties even after UV irradiation and long-term storage in air. † Electronic supplementary information (ESI) available: (1) Video showing the separation of water and organic liquids by superhydrophobic silicon-type gels;(2) video showing the oating behavior of the silicon-type gels aer being pressed under organic liquids. See

A review of femtosecond laser-structured superhydrophobic or underwater superoleophobic porous surfaces/materials for efficient oil/water separation

“…Only oil phase is selectively absorbed by the 3D porous materials. 13,20,23,[30][31][32][33][189][190][191][192][193][194][195][196][197][198][199][200][201][202][203] As the materials are taken out of the mixture liquid, the oil phase is also taken away by the superhydrophobic 3D porous materials, so the oil part in the mixture is removed. The absorbed oil can be easily released and collected for reuse by squeezing the oil-lled porous materials.…”

“…Different from the superwetting separating mesh/membranes, superhydrophobic and superoleophilic 3D porous bulk materials can directly absorb oils from no matter water surface or underwater, thereby the contaminated oils are completely removed from the OWM and be collected for reuse. 190,192,[195][196][197][198][199][200][201][202][203] Oil-absorption 3D materials are better than separating membranes in some special cases towards achieving efficient OWS, such as leaked heavy oils, a small amount of oil being leaked to sea surface, etc. However, laser ablation is not suit to process uneven surface, especially for 3D materials such as foam, sponge, etc.…”

Facile Synthesis of Hollow Glass Microsphere Filled PDMS Foam Composites with Exceptional Lightweight, Mechanical Flexibility, and Thermal Insulating Property

“…As is well known, PDMS foam materials usually show excellent thermal stability (from −80 °C to 240 °C) [ 8 , 9 , 10 ], good mechanical flexibility, and excellent chemical resistance [ 11 ], which is attributed to the high dissociation energy and low-energy barriers to Si-O-Si bond rotations [ 12 , 13 , 14 ]. Therefore, PDMS foam and its composites have been widely developed for versatile applications, such as wearable electronics [ 15 , 16 ], piezoresistive sensors [ 16 ], water/oil separation and absorbents [ 17 ], and thermal insulation materials [ 18 ]. It should be noted that the density of commercial PDMS foam material is usually >200 mg/cm −3 , which is more than those of the traditional hydrocarbon polymer foam materials, e.g., 50–150 mg/cm −3 polyurethane or polystyrene foam, greatly limiting their application in the automobile field, although their other properties are superior to other polymer foams [ 19 , 20 , 21 , 22 , 23 , 24 , 25 ].…”

Facile fabrication of amphiphobic surfaces on copper substrates with a mixed modified solution

“…1 Superhydrophobic surfaces have been fabricated on copper substrates by etching, 2-5 electrodeposition, [6][7][8] femtosecond laser, 9,10 etc., which can repel water but lack oleophobicity at the same time, resulting in the surfaces being readily polluted by low surface energy oils. 11,12 Transforming the amphiphilicity of copper substrates to amphiphobicity can avoid oil and water contamination. 13,14 Amphiphobic surfaces with unique wettability of being both hydrophobic and oleophobic 15 are widely used in the elds of self-cleaning, 16 anti-fouling, 17,18 anti-corrosion, 19,20 etc., which have become a new research focus.…”