Development of superhydrophobic electrospun fibrous membrane of polymers of intrinsic microporosity (PIM-2). (March 2019)

• Record Type: Journal Article
• Authors: Satilmis, Bekir; Uyar, Tamer
• Is Part Of: European polymer journal. Volume 112(2019)
• Page Start: 87
• Page End: 94
• Publication Date: 2019-03
• Subjects: Polymers of Intrinsic Microporosity -- PIM-2 -- Electrospinning -- Membrane -- Nanofibers -- Adsorption -- Superhydrophobic -- Oil removal; Polymers -- Periodicals; Polymerization -- Periodicals; Polymères -- Périodiques; Polymérisation -- Périodiques; Polymerization; Polymers; Periodicals; Electronic journals; 547.705
• DOI: 10.1016/j.eurpolymj.2018.12.029
• Languages: English
• ISSNs: 0014-3057

Abstract

Graphical abstract: Highlights: Bead-free and uniform PIM-2 fibers were produced by electrospinning. Self-standing electrospun PIM-2 fibrous membranes show high surface area. Fibrous membranes demonstrate significantly high hydrophobicity with a water contact angle of 155 ± 6°. Fibrous membranes of PIM-2 were employed in effective organic/oil removal. PIM-2 fibrous membranes show high organic and oil uptake. Abstract: Polymers of intrinsic microporosity (PIMs) are increasingly recognized as a potential membrane material for adsorption and separation applications due to their permanent porosity and solution processability. PIM-2 can be produced using commercially available 5, 5′, 6, 6′-Tetrahydroxy-3, 3, 3′, 3′-tetramethyl-1, 1′-spirobisindane and decafluorobiphenyl monomers in the powder form. It possesses considerable amount of fluorine in the polymer backbone and this feature could provide significant hydrophobicity to polymer. This research aims to investigate the fabrication of self-standing PIM-2 fibrous membranes by electrospinning method to introduce a useful material for adsorption applications. Electrospinning was performed using tetrachloroethane as a solvent and bead-free, uniform fibers were produced as confirmed by SEM imaging. Average fiber diameter was calculated as 5.5 ± 1.5 μm for a self-standing fibrous membrane of PIM-2. Structural characterization was conducted using FT-IR, NMR and XPS spectroscopies showing the purity of pristine powder and fibrous membrane of PIM-2. Thermal stability of PIM-2 fibrous membrane was investigated using TGA and it shows no discernible weight loss below 450 °C. The porosity of fibrous membrane was investigated by N2 adsorption/desorption measurements that indicates significant microporosity with ∼600 m 2 g −1 BET surface area. In addition, the hydrophobicity of PIM-2 was tested by water contact angle measurements, showing 155 ± 6° WCA, indicating superhydrophobicity owing to rough surface and high fluorine content. Consequently, the combination of straightforward synthesis, solution processability, high thermal stability, high surface area, and superhydrophobicity makes PIM-2 a promising candidate for adsorption applications. Therefore, it was successfully employed in organic and oil adsorption. Fibrous membranes of PIM-2 has shown up to 2200 ± 100% and 1900 ± 100% weight gain after in contact with silicon oil and DMSO respectively. In addition, dense membrane of PIM-2 was prepared by solvent casting method and the uptake ability was compared with fibrous membrane showing that fibrous form is more convenient for liquid adsorption applications.