Electrospun polymer blend with tunable structure for oil–water separation

Abstract

In this study, polyurethane (PU) alone or in blend with 10% polystyrene (PS) or poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) was used for electrospinning (ES) of nanofibers. The optimum conditions for obtaining the minimum fiber diameter were found to be [polymer] = 10 wt %, polymer feed rate = 2 mL h−1, voltage = 21 kV, tip to collector distance = 21 cm, and the drum speed = 600 rpm. The time of ES was used as a parameter for controlling the thickness and the average pore size diameter of the membranes. The average pore size diameter decreased almost linearly by increasing the thickness. The resulting electrospun membranes were hydrophobic and oleophilic in nature with the water contact angle above 130°. The hydrostatic pressure head of the membranes increased by decreasing the average pore size diameter. The maximum initial oil separation flux was achieved for the membranes with larger average pore size diameters in the order of: PU9:1PS > PU > PU9:1PVDF‐HFP. The membranes were used for four consecutive cycles without any noticeable loss of separation performance. The diesel oil recovery percentage after 1 h was found to be above 85% for the PU9:1PS and PU membranes. A commercially available polytetrafluoroethylene membrane, with a thickness of 94 μm and the average pore size diameter of 0.45 μm, was used for benchmarking. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46890.

Electrospun nanofibrous polyvinylidene fluoride‐co‐hexafluoropropylene membranes for oil–water separation

“…A similar trend has been observed in other research studies. [ 20,43 ] The results highlight the importance of the AFD on the average pore size diameter and the HPH.…”

“…In previous study, we investigated the effects of various electrospinning parameters (i.e., polymer concentration/viscosity, polymer solution feed rate, applied voltage, and the tip to collector distance) on the average fiber diameter and porosity of the fabricated membranes in a series of papers. [ 30,34,35 ] We also found in our previous study [ 20 ] that the addition of only 10 wt.% poly(vinylidene fluoride‐co‐hexafluoropropylene) (PVDF‐HFP) to polyurethane can change the physical–chemical properties of the fabricated electrospun membrane (e.g., the average fiber diameter, pore size, the hydrostatic pressure head, etc.). The presence of HFP groups in the polymer improve hydrophobicity, [ 36 ] mechanical properties, [ 37 ] thermal and chemical stabilities, [ 38 ] and antifouling properties [ 39 ] of the resulting membrane.…”

“…Polyimide and graphene oxide [18] Coating porous meshes Trimethylsilyl-terminated-poly-(dimethylsiloxane)co-polymethylhydrosiloxane [19] Electrospinning Polyurethane blended with polystyrene or poly(vinylidene fluoride-co-hexafluoropropylene) [20] Phase inversion membrane casting Poly(ethylene-co-methyl acrylate)/ poly(vinylidene fluoride) blend [21] are randomly distributed on the surface of the collector to form a porous mesh or membrane. Electrospun membranes have been used for various applications, as have been reviewed.…”

“…[17] Some of the recent advancements in the field have been summarized in Table 1. The membranerelated parameters (e.g., pore size distribution and thickness, [7,20] surface roughness, [22] and surface hydrophobicity/oleophobicity [23,24] ) and the operating parameters, such as flow velocity, operating pressure, oil concentration/viscosity, and pH, can affect the membrane filtration performance and efficiency. [13] Electrospinning is a promising technique for the fabrication of membranes from polymeric solutions.…”

Fabrication of electrospun fibers from a waterborne soy‐based polyurethane employing polyethylene oxide as a coformer

“…PU have been broadly studied and applied in several fields, either as films, 12 flexible and rigid foams 13,14 or hydrogels, 15 among others, but they have been rarely electrospun as sole materials 16,17 . Instead, blends with large linear polymers have been more popular, 18,19 but only employing traditional solvents. Moreover, biobased polyurethanes (bioPU) have been successfully synthesized from numerous natural sources and would be very interesting eco‐friendly materials to be used.…”