Polyimide/cellulose acetate core/shell electrospun fibrous membranes for oil-water separation

Abstract

In recent years, efficient, cost effective oil-water separation technologies are highly desired due to frequent oil spill accidents. To design fibrous membranes for efficient oil-water separation, 'flexible' polyamide acid (PAA), being polyamide acid with ether linkages in the backbone, and 'heavily' fluorinated polybenzoxazine (F-PB) were synthesized. Cellulose acetate (CA) and PAA were co-axially electrospun; the PAA core was then imidizated at high temperature to obtain core/shell structured CA/polyimide (PI) electrospun fibrous 2 membranes; subsequently the surface of the fibers was modified with F-PB， in the presence or in absence of silica nanoparticles (SNPs). The mechanical strength, surface wettability, chemical and thermal stability, and oil-water separation potential of thus obtained PI/CA fibrous membranes were evaluated. The membranes show a much higher critical tensile stress (130 MPa) and critical tensile strain (52%), when compared with CA fibrous membranes. Due to the use of the 'heavily' fluorinated polybenzoxazine, the membranes are superhydrophobic with a water contact angle of 162 o and an oil contact angle which approaches 0 o. Interestingly, the newly designed PI/CA/F-PB-1/SNP-4 membranes can effectively separate various oil-water mixtures, solely driven by gravity, with a high flux (3106.2 ± 100 L•m-2 •h-1) and a high separation efficiency (> 99%) and thus possess great potential for oil-water separation.

Recent advances in waste lube oils processing technologies

“…The development of superhydrophobic membrane for oilwater emulsions separation was reported [112][113][114][115][127][128][129][130][131][132][133][134][135] as summarized in Table 6. However, there is no publication which clearly states the application of superhydrophobic membrane for waste lube oil processing.…”

Preparation and Applications of the Cellulose Nanocrystal

“…The preparation of the CNC was affected by a series of factors that involved the reaction conditions, the carboxyl content, the homogenization treatment, and other circumstances [43][44][45], in which the carboxyl content of the CNC controlled the dispersity of the cellulose fiber in water as well as the productivity of the CNC [46].…”

Superhydrophobic and Low‐k Polyimide Film with Porous Interior Structure and Hierarchical Surface Morphology

“…Polyimide (PI) is a well‐known engineering plastic that possesses excellent thermal stability, high chemical resistance, good mechanical properties as well as a low dielectric constant (low‐ k ) . Therefore, they have become an excellent candidate for microelectronics applications, such as interlayer dielectrics and flexible circuitry carriers .…”