scholarly journals Membranes for the Capture and Screening of Waterborne Plutonium Based on a Novel Pu-Extractive Copolymer Additive

Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 3
Author(s):  
James C. Foster ◽  
Timothy A. DeVol ◽  
Scott M. Husson
Keyword(s):  
Graft Copolymer ◽  
Alpha Spectrometry ◽  
Vinylidene Fluoride ◽  
Surface Migration ◽  
Peak Energy ◽  
Poly Vinylidene Fluoride ◽  
Dope Solution ◽  
Entire Depth ◽  
Flow Filtration ◽  
Poly Ethylene

This contribution describes the fabrication of plutonium-adsorptive membranes by non-solvent induced phase separation. The dope solution comprised poly(vinylidene fluoride) (PVDF) and a Pu-extractive copolymer additive of PVDF-g-poly(ethylene glycol methacrylate phosphate) (EGMP) in dimethylformamide (DMF). The effects of casting conditions on membrane permeability were determined for PVDF membranes prepared with 10 wt% PVDF-g-EGMP. Direct-flow filtration and alpha spectrometry showed that membranes containing the graft copolymer could recover Pu up to 59.9 ± 3.0% from deionized water and 19.3 ± 3.5% from synthetic seawater after filtering 10 mL of 0.5 Bq/mL 238Pu. SEM-EDS analysis indicated that the graft copolymer was distributed evenly throughout the entire depth of the copolymer membranes, likely attributing to the tailing observed in the alpha spectra for 238Pu. Despite the reduction in resolution, the membranes exhibited high Pu uptake at the conditions tested, and new membrane designs that promote copolymer surface migration are expected to improve alpha spectrometry peak energy resolutions. Findings from this study also can be used to guide the development of extractive membranes for chromatographic separation of actinides from contaminated groundwater sources.

scholarly journals Recent Progress in the Membrane Distillation and Impact of Track-Etched Membranes

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2520
Author(s):  
Arman B. Yeszhanov ◽  
Ilya V. Korolkov ◽  
Saule S. Dosmagambetova ◽  
Maxim V. Zdorovets ◽  
Olgun Güven
Keyword(s):  
Water Purification ◽  
Vinylidene Fluoride ◽  
Liquid Radioactive Waste ◽  
Theoretical Models ◽  
Membrane Distillation ◽  
Narrow Pore Size Distribution ◽  
Poly Ethylene Terephthalate ◽  
Poly Vinylidene Fluoride ◽  
Poly Ethylene ◽  
Purification Of Water

Membrane distillation (MD) is a rapidly developing field of research and finds applications in desalination of water, purification from nonvolatile substances, and concentration of various solutions. This review presents data from recent studies on the MD process, MD configuration, the type of membranes and membrane hydrophobization. Particular importance has been placed on the methods of hydrophobization and the use of track-etched membranes (TeMs) in the MD process. Hydrophobic TeMs based on poly(ethylene terephthalate) (PET), poly(vinylidene fluoride) (PVDF) and polycarbonate (PC) have been applied in the purification of water from salts and pesticides, as well as in the concentration of low-level liquid radioactive waste (LLLRW). Such membranes are characterized by a narrow pore size distribution, precise values of the number of pores per unit area and narrow thickness. These properties of membranes allow them to be used for more accurate water purification and as model membranes used to test theoretical models (for instance LEP prediction).

scholarly journals Preparation and Characterization of TiO2-PVDF/PMMA Blend Membranes Using an Alternative Non-Toxic Solvent for UF/MF and Photocatalytic Application

Molecules ◽  
2019 ◽  
Vol 24 (4) ◽  
pp. 724 ◽  
Author(s):  
Ouassila Benhabiles ◽  
Francesco Galiano ◽  
Tiziana Marino ◽  
Hacene Mahmoudi ◽  
Hakim Lounici ◽  
...  
Keyword(s):  
Phase Separation ◽  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Polymer Concentration ◽  
Inversion Method ◽  
Membrane Morphology ◽  
Photocatalytic Application ◽  
Poly Vinylidene Fluoride ◽  
Dope Solution ◽  
Phase Inversion Method

The approach of the present work is based on the use of poly (methylmethacrylate) (PMMA) polymer, which is compatible with PVDF and TiO2 nanoparticles in casting solutions, for the preparation of nano-composites membranes using a safer and more compatible solvent. TiO2 embedded poly (vinylidene fluoride) (PVDF)/PMMA photocatalytic membranes were prepared by phase inversion method. A non-solvent induced phase separation (NIPS) coupled with vapor induced phase separation (VIPS) was used to fabricate flat-sheet membranes using a dope solution consisting of PMMA, PVDF, TiO2, and triethyl phosphate (TEP) as an alternative non-toxic solvent. Membrane morphology was examined by scanning electron microscopy (SEM). Backscatter electron detector (BSD) mapping was used to monitor the inter-dispersion of TiO2 in the membrane surface and matrix. The effects of polymer concentration, evaporation time, additives and catalyst amount on the membrane morphology and properties were investigated. Tests on photocatalytic degradation of methylene blue (MB) were also carried out using the membranes entrapped with different concentrations of TiO2. The results of this study showed that nearly 99% MB removal can be easily achieved by photocatalysis using TiO2 immobilized on the membrane matrix. Moreover, it was observed that the quantity of TiO2 plays a significant role in the dye removal.

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