scholarly journals Magnetoelectric Membrane Filters of Poly(vinylidene fluoride)/Cobalt Ferrite Oxide for Effective Capturing of Particulate Matter

Polymers ◽  
2020 ◽  
Vol 12 (11) ◽  
pp. 2601
Author(s):  
Kyujin Ko ◽  
Su-Chul Yang
Keyword(s):  
Magnetic Field ◽  
Particulate Matter ◽  
Surface Charge ◽  
Vinylidene Fluoride ◽  
Shape Change ◽  
Membrane Surface ◽  
Public Health Issue ◽  
Membrane Filters ◽  
Phase Alignment ◽  
Poly Vinylidene Fluoride

In the last decade, particulate matter (PM) has gradually become a serious public health issue due to its harmful impact on the human body. In this study, we report a novel filtration system for high PM capturing, based on the magnetoelectric (ME) effect that induces an effective surface charge in membrane filters. To elucidate the ME effect on PM capturing, we prepared electrospun poly(vinylidene fluoride)(PVDF)/CoFe2O4(CFO) membranes and investigated their PM capturing efficiency. After electrical poling under a high electric field of 10 kV/mm, PM-capturing efficiencies of the poled-PVDF/CFO membrane filters were improved with carbon/fluorine(C/F) molar ratios of C/F = 4.81 under Hdc = 0 and C/F = 7.01 under Hdc = 700 Oe, respectively. The result illustrates that electrical poling and a dc magnetic field could, respectively, enhance the surface charge of the membrane filters through (i) a strong beta-phase alignment in PVDF (poling effect) and (ii) an efficient shape change of PVDF/CFO membranes (magnetostriction effect). The diffusion rate of a water droplet on the PVDF/CFO membrane surface is reduced from 0.23 to 0.05 cm2/s by covering the membrane surface with PM. Consequently, the PM capturing efficiency is dramatically improved up to 175% from ME membranes with the poling process and applying a magnetic field. Furthermore, the PM was successfully captured on the prototype real mask derived from the magnetoelectric effect induced by a permanent magnet with a diameter of 2 cm without any external power.

Magnetic field induced formation of ferroelectric β phase of poly (vinylidene fluoride)

2020 ◽  
Vol 126 (8) ◽  
Author(s):  
Jie Wu ◽  
Xiaoyu Sun ◽  
Shunjin Zhu ◽  
Jin Bai ◽  
Xuebin Zhu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Vinylidene Fluoride ◽  
Β Phase ◽  
Poly Vinylidene Fluoride

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.

Preparation and Characterization of Poly(vinylidene) Fluoride Membranes Reinforced by Modified Nano-SiO2 Particles

2014 ◽  
Vol 789 ◽  
pp. 201-204
Author(s):  
Ai Wen Qin ◽  
Xiang Li ◽  
Bo Mou Ma ◽  
Xin Zhen Zhao ◽  
Chun Yi Liu ◽  
...  
Keyword(s):  
Pore Size ◽  
Vinylidene Fluoride ◽  
Cell Structure ◽  
Membrane Surface ◽  
Pure Water ◽  
Water Flux ◽  
Cross Sectional ◽  
Antifouling Property ◽  
Poly Vinylidene Fluoride ◽  
Mechanical Performances

Poly (vinylidene fluoride) (PVDF) hybrid membranes reinforced by hydrophilic nanoSiO2 particles were fabricated from PVDF/N-dimethylacetamide (DMAc)/γ-butyrolactone (γ-BL) system via thermally induced phase separation (TIPS) process. Surface and cross-sectional morphology of membranes were characterized by scanning electron microscope (SEM). The properties such as permeability, mechanical performances and antifouling property were also determined. The results showed that the pore size of membrane surface became smaller, while cross-sectional morphology was changed from bicontinuous structure to cell structure, the pore size became larger and majorities of closed pores became open with the addition of hydrophilic nanoSiO2 particles in the system. Compared with pure membrane, pure water flux of hybrid membrane increased by 30.3%, i.e. from 290 to 378 L/(m2·h·0.1MPa), antifouling property increased from 63.1% to 80.2%. Meanwhile, tensile strength and elongation at break increased by 70.6% and124%, respectively.

scholarly journals Hydrophilic modification of poly(vinylidene fluoride) ultrafiltration membranes by surface UV photo-grafting with N,N′-methylene-bisacrylamide as monomer and Ce(IV) as initiator

2015 ◽  
Vol 6 (2) ◽  
pp. 280-289
Author(s):  
Baoli Shi ◽  
Zheng Li ◽  
Xing Su
Keyword(s):  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Ultrafiltration Membranes ◽  
Water Contact ◽  
Pvdf Membrane ◽  
Hydrophilic Modification ◽  
Poly Vinylidene Fluoride ◽  
Modified Membrane ◽  
Porosity Measurements ◽  
Pure Pvdf

A UV photo-grafting method was utilised to enhance the hydrophilicity and anti-fouling property of self-made poly(vinylidene fluoride) (PVDF) ultrafiltration membranes. N,N′-methylene-bisacrylamide (MBAA) was used as monomer and Ce(IV) was used as initiator to obtain balance between grafting treatment consumption and enhanced performance. MBAA could be grafted onto the surface of pure PVDF membranes through a water-phase grafting method under UV photoradiation. When the MBAA concentration was 0.07 mol/L, the Ce(IV) concentration was 0.04 mol/L, and the irradiation duration was 3 min, the membrane surface was grafted with a sufficient amount of monomer under a UV photoradiation intensity of 5.0 mW/cm2. The water contact angle on the surface of the modified membrane decreased by approximately 16°, and flux recovery increased by approximately 40% compared with the pure PVDF membrane when treating river water. For bovine serum albumin rejection and porosity measurements no significant changes were observed between pure PVDF and graft-treated membranes. The enhanced performance of the modified membrane in this work was moderate, but the UV irradiation duration (3 min) was short. The integrative effects of UV modification in this work were satisfactory when both irradiation duration and enhanced performance were considered.

Fundamental characteristics study of anion-exchange PVDF–SiO2 membranes

2012 ◽  
Vol 66 (11) ◽  
pp. 2343-2348 ◽  
Author(s):  
Xingtao Zuo ◽  
Wenxin Shi ◽  
Shuili Yu ◽  
Jiajie He
Keyword(s):  
Anion Exchange ◽  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Exchange Capacity ◽  
Anion Exchange Membranes ◽  
Blending Method ◽  
Poly Vinylidene Fluoride ◽  
Potential Applications ◽  
Alkaline Membrane ◽  
Exchange Membrane

A new type of poly(vinylidene fluoride)(PVDF)–SiO2 hybrid anion-exchange membrane was prepared by blending method. The anion-exchange groups were introduced by the reaction of epoxy groups with trimethylamine (TMA). Contact angle between water and the membrane surface was measured to characterize the hydrophilicity change of the membrane surface. The effects of nano-sized SiO2 particles in the membrane-forming materials on the membrane mechanical properties and conductivity were also investigated. The experimental results indicated that PVDF–SiO2 anion-exchange membranes exhibited better water content, ion-exchange capacity, conductivity and mechanic properties, and so may find potential applications in alkaline membrane fuel cells and water treatment processes.

scholarly journals Enhancement of Piezoelectric Coefficient (d33) in PVDF-TrFe/CoFe2O4 nanocomposites through DC magnetic poling

2021 ◽  
Author(s):  
Marco Fortunato ◽  
Alessio Tamburrano ◽  
Maria Paola Bracciale ◽  
Maria Laura Santarelli ◽  
Maria Sabrina Sarto
Keyword(s):  
Magnetic Fields ◽  
Electric Fields ◽  
Piezoelectric Coefficient ◽  
Vinylidene Fluoride ◽  
Piezoelectric Materials ◽  
Low Cost ◽  
Sample Surface ◽  
Special Focus ◽  
Phase Alignment ◽  
Poly Vinylidene Fluoride

In the last years flexible, low-cost, wearable and innovative piezoelectric nanomaterials, have attracted a considerable interest to develop energy harvesters and sensors. Among the piezoelectric materials, a special focus was paid on  electroactive polymers such as Poly(vinylidene fluoride) [PVDF] and on its copolymer Poly(vinylidene fluoride-co-trifluoroethylene) [PVDF-TrFe], which is one of the most investigated piezoelectric polymers, due to the high β-phase content resulting under specific curing or processing conditions. However, to get high piezoelectric coefficient (d33), alignment of the β-phase domains is needed, which is usually obtained by applying a high electric fields at moderate temperatures. This process, usually referred as electrical poling, requires the deposition of contact electrodes over the sample surface, and the use of high voltage apparatus.   In the present work, in order to overcome these constraints we have produced, characterized and studied a polymer nanocomposite, consisting of CoFe2O4 nanoparticles dispersed in PVDF-TrFe with enhancement of the β-phase alignment through and applied a DC magnetic fields. The magnetic poling was demonstrated to be particular effective, leading to a piezoelectric coefficient, d33, with values up to 39 pm/V. The magnetic poling does not need the use a top electrode and of high magnetic fields (the maximum value of d33 was obtained at 50 mT, using a current of 0.4 A) making the PVDF-TrFE/CoFe2O4 nanocomposite suitable for the fabrication of highly efficient devices for energy harvesting and wearable sensors.

Preparation and characterization of anti-fouling PVDF membrane modified by chitin

2017 ◽  
Vol 37 (3) ◽  
pp. 313-321 ◽  
Author(s):  
Manman Xie ◽  
Xia Feng ◽  
Juncheng Hu ◽  
Zhengyi Liu ◽  
Zijian Wang ◽  
...  
Keyword(s):  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Solvent System ◽  
Pvdf Membrane ◽  
Blend Membrane ◽  
Poly Vinylidene Fluoride ◽  
And Performance ◽  
Membrane Structure And Performance ◽  
Precipitation Phase

Abstract Poly(vinylidene fluoride) (PVDF)/chitin (CH) blend membranes were prepared via the method of immersion-precipitation phase transformation with the solvent system N,N-dimethylacetamide (DMAc)/lithium chloride (LiCl) as solvent and water as coagulant. The effect of CH on membrane structure and performance was investigated. Owing to the strong hydrophilicity, CH chains enriched on the blend membrane surface and improved the hydrophilicity of the membrane. The addition of CH also led to the formation of finger-like pores and the increase of pore size and porosity. The flux and the flux recovery ratio (FRR) of the blend membrane were higher than that of pure PVDF membrane. The fouling resistance of the blend membrane was lower than that of PVDF original membrane. In a word, the addition of CH to PVDF membrane improved the hydrophilicity and the anti-fouling ability of PVDF membrane.

scholarly journals Optimal modification of poly(vinylidene fluoride) membrane surface by using surface-modifying macromolecules for application in membrane distillation

2017 ◽  
Vol 71 ◽  
pp. 62-78 ◽  
Author(s):  
Reshad Shoaie ◽  
Javad Karimi-Sabet ◽  
Seyed Mohammad Ali Mousavian ◽  
Parissa Khadiv-Parsi ◽  
Rasoul Moradi
Keyword(s):  
Vinylidene Fluoride ◽  
Membrane Surface ◽  
Membrane Distillation ◽  
Poly Vinylidene Fluoride
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