A facile, clean construction of biphilic surface on filter paper via atmospheric air plasma for highly efficient separation of water-in-oil emulsions

A novel method to prepare durable biphilic surface on cellulose filter paper by atmospheric air plasma treatment is reported. The as-prepared sample possessed excellent separation performance for surfactant-stabilized water-in-oil emulsions, of which the filtration efficiency reached 99.13% and the oil recovery purity exceeded 99.98 wt %. The hydrophobic surface with microscale hierarchical structure was constructed with long-chain alkyl silane and SiO2 nanoparticles via plasma-induced crosslinking, on which amino-grafted SiO2 nanoparticles was then fixed through plasma-induced chemical bonding. The water-amino attraction and oil-alkyl attraction would synergistically destabilize the emulsion and hence separate the two phases. The plasma-fabricated coating was very durable against ultrasonication in acetone and can be stored for 12 months without aging. The coating also exhibited excellent recyclability (over 20 cycles). The study may offer a facile, environment-friendly method to prepare filtering materials for highly efficient separation of water-in-oil emulsions.

Automated summary

A novel method utilizing atmospheric air plasma treatment to prepare durable biphilic surface on cellulose filter paper has been reported. The as-prepared sample exhibited excellent separation performance for surfactant-stabilized water-in-oil emulsions, and showed durability against ultrasonication in acetone as well as recyclability for over 20 cycles. This study may provide a facile and environment-friendly approach to prepare filtering materials for highly efficient separation of water-in-oil emulsions.