Nonflammable and Magnetic Sponge Decorated with Polydimethylsiloxane Brush for Multitasking and Highly Efficient Oil–Water Separation

Abstract

Developing sponge materials integrating excellent flame retardancy, multitasking separation performance, and efficient emulsion-breaking ability is significant but challenging for the remediation of oil spills causing fires and environmental damages. Herein, a superhydrophobic oil-water separation sponge material, containing a melamine-formaldehyde (MF) sponge substrate, magnetic polydopamine (PDA) coating, and branched polydimethylsiloxane (PDMS) brush, through dopamine-mediated surface initiated atom transfer radical polymerization (SI-ATRP) is fabricated. The synergistic flame resistance of the MF substrate and PDMS brush significantly improves its adaptability in fire. More importantly, the decorated PDMS brushes can effectively overcome the size mismatch between sponge macropores and tiny emulsified droplets, while remaining the intrinsic macroporous characteristic. When treating W/O emulsions, the PDMS brushes stretch up to act as "interface-breaking blades" to accelerate the coalescence of emulsified water droplets. Meanwhile, such PDMS brushes can serve as "oil-trapping tentacles" to efficiently capture oil droplets when treating O/W emulsions. Such material design synergistically contributes to satisfactory separation efficiency (98.7%) and ultrahigh permeation flux (up to 1.35 × 10 5 L m −2 h −1 ), even for treating high viscosity emulsions. Besides, the reported sponge also inherits robust durability, superior recyclability, and convenient magnetic collection. These features make the sponge promising for multitasking and highly efficient oil-water separation.

Superhydrophobic paper with mussel-inspired polydimethylsiloxane–silica nanoparticle coatings for effective oil/water separation

“…6D shows the ATR-FTIR spectra of the samples. Compared with the pristine paper, all the spectra of the washed PDMS-SiO 2 /PDA/paper exhibit the characteristic signals of Si-C bond (at 1257 and 780 cm À1 ), Si-O-Si bond (at 1070 cm À1 ), and C-H stretching vibration (at 2962 cm À1 ), 30 suggesting the good stability of PDMS-SiO 2 layer on the PDA modied paper substrate. Seen from Fig.…”

“…Hydrophobic polydimethylsiloxane (PDMS) is one of the most important materials in the preparation of superhydrophobic and superoleophobic surfaces based on its very low surface tension and self-roughening. [27][28][29][30][31][32] Dopamine, the most renowned catecholamine, is able to undergo self-polymerization under oxidizing conditions, creating a bioinspired surface-adherent polydopamine (PDA) coating on almost all kinds of organic and inorganic surfaces. [33][34][35][36] Moreover, PDA chains incorporate many functional groups such as catechol, amine, and imine, that can serve as the reactive sites with desired molecules and the anchors for the loading of transition metal ions via bidentate coordination, hydrogen bonding, Michael addition or Schiff base reactions for efficient oil/water separation.…”

Strategic Advances in Spatiotemporal Control of Bioinspired Phenolic Chemistries in Materials Science

“…[261] For example, Liu et al developed a rapid DA codeposition-mediated SI-ATRP strategy to grow branched PDMS brushes on commercial melamine-formaldehyde (MF) sponge for multitasking and highly efficient oil-water separation. [262] In particular, magnetic Fe 3 O 4 nanoparticles were simultaneously incorporated into the system to result in a nonflammable, magnetic, and superhydrophobic sponge (Figure 13b).…”

One‐Pot Route for Fe@Poly(styrene‐co‐divinylbenzene) Foam with Robust Physical/Chemical Stability and Remote Magnetic Driven Capacity for Oil Removal

“…To address this problem, superhydrophobic/superoleophilic materials with magnetic driven capacity have been developed, in which an external magnetic field can be utilized to drive the oil confinement of polluted water both above and below the water surface by the as-prepared materials, for selective oil collection. [38][39][40] For example, Yang et al reported a kind of magnetic, superhydrophobic large-sized paper, decorated with Fe 3 O 4 nanoparticles to act as an oil-collecting device for realizing remote controllability. [41] Zhang et al introduced iron oxide (Fe 3 O 4 ) nanoparticles and alkylated SiO 2 nanoparticles on engineered polyurethane sponges to prepare magnetically driven functionality, for specific oil pollution locations, which shows excellent elasticity and good stability regarding broad temperature changes and/or corrosive solutions.…”