Preparation of Superwetting Porous Materials for Ultrafast Separation of Water-in-Oil Emulsions

Abstract

Functional materials with a superwetting surface property have been extensively explored to achieve emulsion separation. In this paper, we report a simple and inexpensive method for fabricating superhydrophobic/superoleophilic porous materials from polymeric sponges. These microstructured porous materials, which do not contain any fluorinated compounds, maintain their superhydrophobicity and superoleophilicity after long-term organic solvent immersion and display environmental stability. These superhydrophobic porous materials can effectively separate a wide range of water-in-oil emulsions including surfactant-free and surfactant-stabilized water-in-oil emulsions with high efficiency (>99.98%) and high flux (up to 155 000 L m h bar). Meanwhile, these materials exhibited excellent pH resistance and antifouling properties. The high performance of our superhydrophobic porous materials and their efficient, low-energy, cost-effective preparation suggest that they have a great potential for practical applications.

3D Multiscale Superhydrophilic Sponges with Delicately Designed Pore Size for Ultrafast Oil/Water Separation

“…However, this approach has some disadvantages, such as high cost, complicated modification, and the bonding strength between the nanofibers and the SiO 2 nanoparticles cannot be guaranteed during the operation. The other strategy is the direct use of commercial sponges and metal foams with 3D structures (most of them with pore size from 100 to 500 µm) as the substrates, followed by the postmodification to achieve the required pore structure and wettability. In this case, the mainframe of the filters is fixed so that the pore size cannot be drastically tuned, which renders these materials unfavorable in separating emulsions with droplet sizes less than 20 µm despite their high flux.…”

Effective Separation of a Water in Oil Emulsion from a Direct Contact Latent Heat Storage System

“…However, as previously stated, the lifetime of such a filter remains uncertain. Superhydrophobic surfaces have gained attention in different fields of interest, such as water repelled surfaces for self-cleaning materials [25,26], production of anti-corrosion and anti-fouling surfaces [27] as well as oil-water separation [23,24,28,29].…”

“…In this study: (i) a hydrophilic glass membrane and (ii) a superhydrophobic filter are considered. As described by other works, mainly two different types of filtration methods can be listed for separating water in oil emulsions: hydrophilic membranes, which work as a coalescence separator [20,21] and superhydrophobic filter, which are permeable to the oil phase and impermeable to the aqueous phase [22][23][24].…”

A Scalable Chemical Approach for the Synthesis of a Highly Tolerant and Efficient Oil Absorbent

“…Moreover, the high compressibility provided a facile basis for energy‐efficient and environment friendly removal of the absorbed oil, compared to the other existing approaches‐such as refluxing, burning etc . The low density (≈10 mg cm −3 ), high porosity (average pore size of 150±5 μm) of melamine foam inherently allowed greater absorption of the oily phase, selectively, after embedding the selected spongy substrate with artificial superhydrophobicity . However, in literature till date the demonstration of oil/water separation at practically relevant severe settings has barely been demonstrated with the superhydrophobic MF sponge, likely due to the poor durability of the embedded superhydrophobicity in the reported materials.…”

“…[31,32] The lowd ensity ( % 10 mg cm À3 ), high porosity (average pore size of 150 AE 5 mm) of melamine foam inherently allowed greater absorption of the oily phase, selectively,a fter embedding the selected spongy substrate with artificial superhydrophobicity. [33][34][35][36][37][38] However, in literature till date the demonstration of oil/water separation at practically relevant severe settings has barely been demonstrated with the superhydrophobic MF sponge, likely due to the poor durability of the embedded superhydrophobicity in the reported materials. For instance, Li et al [39] synthesized the graphydene based melamine foam for selective absorption of the oil phase.…”