Polyethylene Coated with MnO₂ Nanoparticles as Thin Film Composite Membranes for Organic Solvent Nanofiltration

Abstract

A thin film composite (TFC) membrane with superior characteristics for organic solvent nanofiltration (OSN) was successfully prepared. Accordingly, a state-of-the-art polyethylene (PE) membrane support was first prepared through etching the polystyrene (PS)/styrene–ethylene–butylene–styrene (SEBS) phase, as the dispersed phase, from the fabricated PE/SEBS/PS composite using the solvent extraction technique. Different compositions were fabricated so that a suitable ultrafiltration membrane support could be achieved. Due to the high hydrophobicity of the prepared PE membrane support (Etched PE) and lack of polar functional groups on its surface, the impregnation with an m-phenylenediamine (MPD) aqueous solution and, consequently, the formation of the polyamide layer on the PE surface were restricted. Hence, the prepared PE membrane supports were immersed in potassium permanganate (KMnO4) solutions with different concentrations so that the PE surface could be oxidized, by which polar functional groups were generated and manganese­(IV) dioxide (MnO2) nanoparticles were also formed on the surface via a relatively strong bond. Next, MPD and trimesoyl chloride (TMC) monomers with different concentrations were utilized for the formation of a cross-linked TFC layer on the MnO2-loaded PE surface. The TFC membranes showed a hydrophilic and defect-free polyamide barrier layer, high separation performance (dye rejection as high as 99.8% for methyl green), methanol permeance of 7 L/m2·h, and high methanol permeance after dimethylformamide (DMF) activation (14 L/m2·h). Furthermore, a superior solvent resistance (dye rejections of more than 98.5, 97.0, 96.0, and 93.5% for methyl green, rhodamine B, crystal violet, and methylene blue, respectively, being immersed in DMF at 75 °C for about 100 days) was exhibited by the prepared membranes, which demonstrated their promising potential in the OSN applications.

TFN Membrane Fabricated by a Gyroid-like PE Support, a Basil Seed Mucilage–Fe(III) Interlayer, and a Polyamide Active Layer Incorporated with MIL-101(Cr)–NH2 Nanoparticles

“…45 Furthermore, it is noteworthy that in this method, the pore size is defined as the dispersed phase size, which has been extracted from the sheet, and so the dispersed phase is regarded as the porogen phase. 16,45 The mechanical properties of the PE membrane, including the tensile strength, elongation at break, and Young's modulus, were evaluated and compared with the commercialized SRNF supports, as listed in Table S2. Based on this table, it can be confirmed that the PE membrane possesses greater mechanical properties than the commercialized ones.…”

“…13−15 The porous support membrane is generally prepared by a variety of cross-linked polymers, for example, polyimides. 8,16 However, it is vital to cross-link these membranes so that they can withstand in chemically harsh media. 17 According to the literature, huge amounts of solvents, post-treatments, and time are necessary in order to carry out the cross-linking step.…”

Macroscale Conjugated Microporous Polymers: Controlling Versatile Functionalities Over Several Dimensions

“…CMP membrane, which is superior to most reported organic solvent nanofiltration membranes. [187,188]…”

“…A stable methanol permeance of 28 L m −2 h −1 bar −1 was achieved for the CMP membrane, which is superior to most reported organic solvent nanofiltration membranes. [ 187,188 ]…”

An In Situ Incorporation of Acrylic Acid and ZnO Nanoparticles into Polyamide Thin Film Composite Membranes for Their Effect on Membrane pH Responsive Behavior

“…Nanoparticles, such as ZrO 2 , Al 2 O 2 , SiO 2 , Fe 3 O 4 , ZnO, and TiO 2 , have been reported to impart hydrophilicity onto modified PA-TFC membrane surfaces [8][9][10][11]. As such, their incorporation into PA-TFC membranes improves the water permeability and fouling resistance of PA-TFC membrane surfaces.…”