Porous and hydrophobic graphene-based core–shell sponges for efficient removal of water contaminants

Abstract

Water pollution is a global environmental problem that has attracted great concern, and functional carbon nanomaterials are widely used in water treatment. Here, to optimize the removal performance of both oil/organic matter and dye molecules, we fabricated porous and hydrophobic core–shell sponges by growing graphene on three-dimensional stacked copper nanowires. The interconnected pores between the one-dimensional nanocore–shells construct the porous channels within the sponge, and the multilayered graphene shells equip the sponge with a water contact angle over 120° even under acidic and alkaline environments, which enables fast and efficient cleanup of oil on or under the water. The core–shell sponge can absorb oil or organic solvents with densities 40–90 times its own, and its oil-sorption capacity is much larger than those of other porous materials like activated carbon and loofah. On the other hand, the adsorption behavior of the core–shell sponge to dyes including methyl orange (MO) and malachite green (MG), also common water pollutants, was also measured. Dynamic adsorption of MG under cyclic compression demonstrated a higher adsorption rate than that in the static state, and an acidic environment was favorable for the adsorption of MO molecules. Finally, the adsorption isotherm for MO molecules was analyzed and fitted with the Langmuir model, and the adsorption kinetics were studied in depth as well.

Preparation of porous poly(4‐tert‐butylstyrene) based monoliths with high efficiency for oil‐water separation via high internal phase emulsion template

“…[12][13][14] In a range of oil absorbing materials, threedimensional (3D) monolithic porous materials are considered as expectative materials for oil absorbing due to their large specific surface area, low density, high porosity and easy recovery. [15][16][17] Commonly used 3D monolithic porous materials mainly include aerogels, [18][19][20] sponges, [21][22][23] and foams. [24][25][26] These materials have interconnected pore structures that can absorb oil via capillary action, and can swell as they absorb oil, allowing the internal voids to absorb more oil.…”

“…In a range of oil absorbing materials, three‐dimensional (3D) monolithic porous materials are considered as expectative materials for oil absorbing due to their large specific surface area, low density, high porosity and easy recovery 15–17 . Commonly used 3D monolithic porous materials mainly include aerogels, 18–20 sponges, 21–23 and foams 24–26 .…”

Electrospun Structural Hybrids of Acyclovir-Polyacrylonitrile at Acyclovir for Modifying Drug Release

“…Coaxial electrospinning, an updated edition of the single-fluid blending electrospinning, is popular due to its capability of creating core-shell nanostructures [70][71][72][73]. Different from the uni-axial nanofibers, core-shell nanofibers can provide the desired drug-modified release profiles from more adjustable elements, as well as the properties of polymer matrices [74].…”