Micro-nano structure poly(ether sulfones)/poly(ethyleneimine) nanofibrous affinity membranes for adsorption of anionic dyes and heavy metal ions in aqueous solution

Gold-recovery PVDF membrane functionalized with thiosemicarbazide

“…Therefore, the different coordination chemistry between -(C@S)-NH 2 and Au(III) in different forms may well be the reason why the two breakthrough curves look different. At pH 3.0, high concentration of protons would protonate amine groups to form -NH þ 3 groups [22], causing strong electrostatic attraction between the Th-PVDF membrane and AuCl À 4 which allows for quicker or more adsorption. At pH 9.0, there exists strong electrostatic repulsion between -NH 2 OH À and, AuðOHÞ À 4 giving rise to difficulties for Au(III) to come close to the adsorption site, which in turn causes slower or less adsorption [13].…”

High-flux affinity membranes based on cellulose nanocomposites for removal of heavy metal ions from industrial effluents

“…[3][4][5] Rather than operating purely on the sieving mechanism, adsorption membrane based on the selectivity of the membrane to 'capture' contaminants, by immobilizing specic ligands or specic functional groups onto the surface of membranes. Affinity membrane reects technological advances in both xed-bed liquid separation and membrane ltration, and combines both the outstanding selectivity and the reduced pressure drops associated with ltration membranes.…”

Polyethylenimine nanofibrous adsorbent for highly effective removal of anionic dyes from aqueous solution

“…For instance, many excellent CO 2 adsorbents have been prepared by integrating PEI into porous materials, including silica [12], mesoporous carbon [13], titanate [14], polymeric supports [15], and other metal oxide nanocomposites [16]. In addition, because of the high positive charge density on the protonated PEI backbone or side chains, PEI-based adsorbents exhibit good adsorption capacity for acidic gas or anionic materials such as polyanions and negatively charged organic or inorganic matter, including various anionic dyes [16][17][18][19].Electrospinning is an effective approach to prepare ultrafine fibers; it uses an electrostatic force from an external high-voltage electrical field between a spinneret and a grounded collector to draw very fine (typically micro-to nanoscale) fibers from a liquid droplet [20]. The ultrafine fibers produced by electrospinning have very high specific ABSTRACT We prepared a nanofibrous adsorbent for anionic dye removal from aqueous solution by electrospinning a modified polyethylenimine (m-PEI) and polyvinylidene fluoride (PVDF) blend.…”

“…For instance, many excellent CO 2 adsorbents have been prepared by integrating PEI into porous materials, including silica [12], mesoporous carbon [13], titanate [14], polymeric supports [15], and other metal oxide nanocomposites [16]. In addition, because of the high positive charge density on the protonated PEI backbone or side chains, PEI-based adsorbents exhibit good adsorption capacity for acidic gas or anionic materials such as polyanions and negatively charged organic or inorganic matter, including various anionic dyes [16][17][18][19].…”