New Hybrid Nanofiltration Membranes with Enhanced Flux and Separation Performances Based on Polyphenylene Ether-Ether-Sulfone/Polyacrylonitrile/SBA-15

Abstract

This study presents the preparation of hybrid nanofiltration membranes based on poly(1,4-phenylene ether ether sulfone), polyacrylonitrile, poly(vinyl pyrrolidone), and SBA-15 mesoporous silica. Laser treatment of polymeric solutions to enhance the hydrophilicity and performance of membranes was investigated. The membranes’ structure was characterized using scanning electron (SEM) and atomic force (AFM) microscopy and contact angle measurements. The addition of PAN in the casting solution produced significant changes in the membrane structure, from finger-like porous structures to sponge-like porous structures. Increased PAN concentration in the membrane composition enhanced the hydrophilicity of the membrane surface, which also accounted for the improvement in the antifouling capabilities. The permeation of apple pomace extract and the content of polyphenols and flavonoids were used to evaluate the efficacy of the hybrid membranes created. The results showed that the hybrid nanofiltration membranes based on PPEES/PAN/PVP/SBA-15: 15/5/1/1 and 17/3/1/1 exposed to laser for 5 min present a higher rejection coefficient to total polyphenols (78.6 ± 0.7% and 97.8 ± 0.9%, respectively) and flavonoids (28.7 ± 0.2% and 50.3 ± 0.4%, respectively) and are substantially better than a commercial membrane with MWCO 1000 Da or PPEES-PVP-based membrane.

Electrochemical Detection Of Heavy Metals In Raw Materials Using a Glassy Carbon Electrode Modified With 4-Aminothiophenol

“…Better electrochemical performances (lower detection limit and a large domain of concentrations) of the developed sensor were achieved in comparison with other electrodes previously reported in literature (Table II). [18][19][20][21][22][23] Interference study.-The modified electrode was tested for the potential detection of other heavy metals. For a standard solution with 200 μg l −1 Zn(II) a peak is observed at −1.1 V with a height of 55 nA and thus the sensitivity is much lower.…”

“…The by-products of fruit and vegetable processing contain significant amounts of biologically active compounds like polyphenols, flavonoids, and carotenoids that could be further used in food and pharmaceutical supplements. 22 Grape pomace is the main by-product of the wine industry, resulting from the fermentation process, and apple pomace is a by-product left over from cider and juice companies. Three types of extracts obtained from the processing of grapes and apples were analyzed with the sensor developed and optimized: hydroalcoholic extract from grape pomace; hydroalcoholic extract from apple pomace; aqueous grape pomace extract.…”

“…The microfiltration was performed through microfiltration membranes with a pore size of 0.45 μm, at a pressure of 4 bar, using the KMS Laboratory Cell CF-1 laboratory installation. 22 The obtained solutions were diluted with acetate solution pH 4.5, in a volumetric ratio of 1:20, directly in the electrochemical cell and then analyzed.…”

Enrichment of Total Flavonoids and Licochalcone A from Glycyrrhiza inflata Bat. Residue Based on a Combined Membrane–Macroporous Resin Process and a Quality-Control Study

“…The membrane flux was tracked by measuring the volume of filtrate collected at a set interval with a graduated cylinder in accordance with Equation (3) [41]:…”

Thorium Removal, Recovery and Recycling: A Membrane Challenge for Urban Mining

“…This membrane allows the separation of the considered system, consisting of a continuous phase (solvent) in which ionic chemical species, molecules and macromolecules are dissolved. At the same time, molecular aggregates and dispersed particles can be separated into components by classical or membrane processes [ 174 ]. In order for the separation process to occur, the system must be subjected to an electrochemical potential difference or driving force (Δµ) [ 175 ].…”