Phosphonium-defoliated GO nanosheets as micropore booster of carbon membrane to improve separation of tetracycline from isopropanol. Issue 3 (June 2022)

• Record Type: Journal Article
• Authors: Priyadarshini, Antara; Hong, Liang; Bera, Ranadip
• Is Part Of: Journal of environmental chemical engineering. Volume 10:Issue 3(2022)
• Publication Date: 2022-06
• Subjects: Carbon-graphene composite membrane -- Defoliated graphene oxide -- Graphitization -- Organic solvent nanofiltration -- Pyrolysis of bitumen; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2022.107496
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: This study developed a supported carbon membrane (CM) to conduct organic solvent nanofiltration (OSN). The OSN performance was tuned up by dispersing phosphonium-defoliated graphene oxide (PGO) as filler (0.3 wt%) in the precursor (bitumen) coating. PGO was synthesized through anchoring phosphonium (Ph3 PBu + ) ions to the oxygenated groups dangled on individual GO sheets that take up 49 wt% of PGO. As PGO experiences elimination of the pendant organic functional groups to form a graphene-like sheet through the course of pyrolysis and carbonization that converts the precursor coating to CM, the graphene-like sheets thus act to induce in-situ face-to-face stacking of the planar polyaromatic hydrocarbons (PAHs) generated from the pyrolysis of bitumen in nanoscale. PGO achieved a superior efficacy of induction than GO because of the defoliating role of phosphonium ion that assures a higher dispersity of graphene-like sheets in the precursor coating. This mechanism in the end casts a higher pore volume in membrane CMPGO than in CMGO (600 vs. 334 μl/g) primarily associating with the micro and meso pores inside the carbonaceous grains (~15–20 nm) that constitute the membrane. These tiny pores connect with the grain boundaries (3–5 nm) to form a porous network in the membrane. Moreover, the resultant membrane operates through a dual interaction model of adsorption and size screening. Membrane CMPGO manifests 99.2~94.2% retention of tetracycline (TC) from the permeate (isopropanol) with an average permeance of 32 L/m 2 ·h·bar over 30 h, whereas the control, CMGO, shows progressive declining from 82% to 30% in 10 h. CMPGO was also evaluated by using the oppositely-charged dyes of different sizes to examine the effect of solute identity on percolation. Graphical Abstract: ga1 Highlights: Carbon membrane (CM) uses phosphonium-defoliated graphene oxide (PGO) as filler. PGO-doped CM is formed via curing/pyrolysis of a bitumen coating on a steel disc. PGO promotes micro-graphitization inducing higher nano-porosity for nanofiltration. Micro pores constitute vital spots of the permeation network to perform separation. Size screening synergizes with adsorption to trade off rejection and permeance.