Facile Fabrication of Marine Algae-Based Robust Superhydrophobic Sponges for Efficient Oil Removal from Water

Abstract

Water pollution caused by oil spillages has aroused worldwide attention. Therefore, it is of great significance to develop low-cost, environmentally friendly materials to remove oil contaminants from water. Herein, a “green” superhydrophobic sponge made from marine algae was fabricated by one-step growth of silicone nanofilaments onto a AgNP-decorated alginate sponge via chemical vapor deposition of an azeotrope of (CH 3 ) 3 SiCl and SiCl 4 . The reaction of the azeotrope with the alginate sponge was termed “instant”, as it took only a few minutes (5 min) at room temperature to achieve superhydrophobicity (152.0°). Such sponges resist high temperatures, UV irradiation, organic solvents, and mechanical abrasion without losing the superhydrophobicity. The sponges absorbed oil droplets within seconds (1.3–7.0 s) with 11.7–17.1 g/g of sorption capacities for oils of different viscous levels (0.56–1775.00 mPa·s). These sponges could retain 90% of the initial oil sorption capacities after 10 consecutive oil sorption/desorption cycles. Benefiting from the superhydrophobicity and superoleophilicity, the sponges also exhibited high efficiency in oil/water mixture separation. Once the oil/water mixture was injected into the sponge, oil drops were retained in inner pores while water was rejected and spouted from the surface. These excellent performances make the resultant sponge a competitive material for oil spill emergency remediation.

Recent Advances in Multifunctional Mechanical–Chemical Superhydrophobic Materials

“…Sponges ( Zhu et al, 2013 ; Cheng et al, 2019a ; Dong et al, 2020 ), textiles ( Luo et al, 2021 ; Zhou et al, 2021 ), foamed nickel ( Hu et al, 2017 ; Eum et al, 2019 ; Wang et al, 2021 ), and other materials ( Hou Y. et al, 2015 ) with multiple layers and porous ( Figure 2B ), due to their large specific surface area, even if part of the material surface is rubbed off, the material still remains, so it has abrasion resistance and is an excellent superhydrophobic material. Superhydrophobic textiles ( Luo et al, 2021 ) are manufactured by decorating the textiles modified by polydopamine (PDA) with MXene (Ti 3 C 2 T x ) and then coating with polydimethylsiloxane (PDMS).…”

Facile Fabrication of Electrospun Nanofibrous Aerogels for Efficient Oil Absorption and Emulsified Oil–Water Separation

“…Some synthetic polymer aerogels have improved mechanical properties and reusability, but many shortcomings, such as low oil sorption capacity and hydrophobicity, limit their commercial application. For sustainable bio-aerogels, such as cellulose aerogels (natural cellulose ones, regenerated cellulose ones, and cellulose-derivate ones), chitosan, gelatin, wood, and marine algae, the separation efficiency and mechanical robustness are low. Simultaneously, carbon-based aerogels, such as carbon nanotubes, carbon fibers, graphene, and the corresponding composite aerogels, demonstrate superior absorption capacities and recyclability. , However, some limitations remain, such as expensive raw materials, low efficiency, and complicated fabrication processes, which significantly limit their practical applications.…”

Silicone Nanofilament Coatings as Flexible Catalyst Supports for a Knoevenagel Condensation Reaction in Batch and Flow Systems

“…Substrates coated with SNFs lead to a significant increase in the surface area, 3 exhibited superhydrophobicity due to surface roughness, 1 and demonstrated excellent thermal and chemical stability. 1,3 To date, there is a significant amount of research interest in utilizing SNFs to develop surfaces with extreme wetting properties, such as superhydrophobic, 4,5 superoleophilic, 6,7 and superamphiphobic surfaces. 8,9 Most of the applications were related to self-cleaning, 5,10,11 antifouling, 12,13 or oil/water separation purposes.…”