Novel Poly(Vinylidene Fluoride)/Montmorillonite Polymer Inclusion Membrane: Application to Cr(VI) Extraction from Polluted Water

Novel hybrid polymer inclusion membranes (PIMs) based on poly(vinylidene fluoride) (PVDF) (polymer matrix) and Aliquat 336 (ion carrier) and containing native sodium (Cloisite Na+ (CNa)) and organo-modified (Cloisite 30B (C30B)) Montmorillonites were elaborated and tested for the removal of toxic Cr(VI) ions from the aqueous solution. The influence of the nanoclay incorporation on the physicochemical properties of PVDF-based PIMs was studied and the resulting membrane transport properties of the Cr(VI) ions were investigated in detail. The water contact angle measurements reveal that the incorporation of the CNa nanofiller affects the membrane wettability as less hydrophilic surface is obtained in this case—~47° in the presence of CNa as compared with ~15° for PIMs with C30B. The membrane rigidity is found to be dependent on the type and size of the used Montmorillonite. The increase of Young’s modulus is higher when CNa is incorporated in comparison with C30B. The stiffness of the PIM is strongly increased with CNa amount (four times higher with 30 wt %) which is not the case for C30B (only 1.5 times). Higher Cr(VI) permeation flux is obtained for PIMs containing CNa (~2.7 µmol/(m2·s)) owing to their porous structure as compared with membranes loaded with C30B and those without filler (~2 µmol/(m2·s) in both cases). The PIM with 20 wt % of native sodium Montmorillonite revealed satisfactory stability during five cycles of the Cr(VI) transport due to the high membrane rigidity and hydrophobicity. Much lower macromolecular chain mobility in this case allows limiting the carrier loss, thus increasing the membrane stability. On the contrary, a deterioration of the transport performance is recorded for the membrane filled with C30B and that without filler. The obtained results showed the possibility to extend the PIM lifetime through the incorporation of nanoparticles that diminish the carrier loss (Aliquat 336) from the membrane into the aqueous phase by limiting its mobility within the membrane by tortuosity effect and membrane stiffening without losing its permselective properties.

Download Full-text

Nanostructured Polymer Brushes With Reversibly Changing Properties

MRS Proceedings ◽

10.1557/proc-727-r2.5 ◽

2002 ◽

Vol 727 ◽

Author(s):

Denys Usov ◽

Manfred Stamm ◽

Sergiy Minko ◽

Christian Froeck ◽

Andreas Scholl ◽

...

Keyword(s):

Polymer Brushes ◽

Phase Segregation ◽

Water Contact ◽

Angle Measurements ◽

Nanostructured Polymer ◽

Contact Angle Measurements ◽

Vertical Segregation ◽

Oxygen Plasma Etching ◽

Grafting From ◽

Photoemission Electron

AbstractWe investigated the interplay between different mechanisms of the lateral and vertical segregation in the synthesized via “grafting from” approach symmetric A/B (where A and B are poly(styrene-co-2,3,4,5,6-pentafluorostyrene) and poly(methylmethacrylate), respectively) polymer brushes upon exposure to different solvents. We used X-ray photoemission electron spectroscopy and microscopy (X-PEEM), AFM, water contact angle measurements, and oxygen plasma etching to study morphology of the brushes. The ripple morphology after toluene (nonselective solvent) revealed elongated lamellar-like domains of A and B polymers alternating across the surface. The dimple-A morphology consisting of round clusters of the polymer A was observed after acetone (selective solvent for B). The top layer was enriched with the polymer B showing that the brush underwent both the lateral and vertical phase segregation. A qualitative agreement with predictions of SCF theory was found.

Download Full-text

Epoxy/alumina composite coating on welded steel 316L with excellent wear and anticorrosion properties

Scientific Reports ◽

10.1038/s41598-021-91741-y ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Maryama Hammi ◽

Younes Ziat ◽

Zakaryaa Zarhri ◽

Charaf Laghlimi ◽

Abdelaziz Moutcine

Keyword(s):

Electrochemical Behaviour ◽

Sem Analysis ◽

Water Contact ◽

Welded Steel ◽

Melted Zone ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Alumina Composite ◽

The Cost ◽

Good Contrast

AbstractThe main purpose of this study is to elaborate anticorrosive coatings for the welded steel 316L, since this later is widely used in industrial field. Hence, within this work we have studied the electrochemical behaviour of different zones of the welded steel 316 in 1 M HCl media. The macrography study of the welded steel has revealed the different areas with a good contrast. We have stated three different zones, namely; melted zone (MZ), heat affected zone (HAZ) and base metal zone (BM). Impedance studies on welded steel 316L were conducted in 1 M HCl solution, coating of Epoxy/Alumina composite was applied on different zones, in order to reveal the anti-corrosion efficiency in each zone. Scanning electron microscopy (SEM) analysis was undertaken in order to check how far the used coating in such aggressive media protects the studied zones and these findings were assessed by water contact angle measurements. The choice of this coating is based on the cost and the safety. We concluded that the Epoxy/Alumina composite has a good protecting effect regarding welded steel in aggressive media.

Download Full-text

PLA-Based Hybrid and Composite Electrospun Fibrous Scaffolds as Potential Materials for Tissue Engineering

Journal of Nanomaterials ◽

10.1155/2017/9246802 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 9

Author(s):

Anna Magiera ◽

Jarosław Markowski ◽

Elzbieta Menaszek ◽

Jan Pilch ◽

Stanislaw Blazewicz

Keyword(s):

Tissue Engineering ◽

Mechanical Tests ◽

Hybrid Structures ◽

Poly Lactic Acid ◽

Electrospinning Technique ◽

Water Contact ◽

Human Osteoblasts ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Normal Human

The aim of the study was to manufacture poly(lactic acid)- (PLA-) based nanofibrous nonwovens that were modified using two types of modifiers, namely, gelatin- (GEL-) based nanofibres and carbon nanotubes (CNT). Hybrid nonwovens consisting of PLA and GEL nanofibres (PLA/GEL), as well as CNT-modified PLA nanofibres with GEL nanofibres (PLA + CNT/GEL), in the form of mats, were manufactured using concurrent-electrospinning technique (co-ES). The ability of such hybrid structures as potential scaffolds for tissue engineering was studied. Both types of hybrid samples and one-component PLA and CNTs-modified PLA mats were investigated using scanning electron microscopy (SEM), water contact angle measurements, and biological and mechanical tests. The morphology, microstructure, and selected properties of the materials were analyzed. Biocompatibility and bioactivity in contact with normal human osteoblasts (NHOst) were studied. The coelectrospun PLA and GEL nanofibres retained their structures in hybrid samples. Both types of hybrid nonwovens were not cytotoxic and showed better osteoinductivity in comparison to scaffolds made from pure PLA. These samples also showed significantly reduced hydrophobicity compared to one-component PLA nonwovens. The CNT-contained PLA nanofibres improved mechanical properties of hybrid samples and such a 3D system appears to be interesting for potential application as a tissue engineering scaffold.

Download Full-text

Fast and simple fabrication of SiO2/poly(vinylidene fluoride) coated cotton fabrics with asymmetric wettability via a facile spray-coating route

Textile Research Journal ◽

10.1177/0040517518760755 ◽

2018 ◽

Vol 89 (6) ◽

pp. 1013-1026 ◽

Cited By ~ 3

Author(s):

Rongrong Yu ◽

Mingwei Tian ◽

Lijun Qu ◽

Shifeng Zhu ◽

Jianhua Ran ◽

...

Keyword(s):

Thermal Conductivity ◽

Contact Angle ◽

Water Contact Angle ◽

Vinylidene Fluoride ◽

Spray Coating ◽

Cotton Fabrics ◽

Water Repellent ◽

Water Contact ◽

Repellent Property ◽

Poly Vinylidene Fluoride

Cotton fabrics with hydrophilic-to-hydrophobic asymmetric surfaces are attractive as potential utilizable structures for functional garments. The spray-coating route could be deemed as a fast and simple way to achieve asymmetric surfaces. In this paper, SiO2 nanoparticles with size ∼ 205 nm were synthesized via the modified sol-gel method, and then modified with poly(vinylidene fluoride) (PVDF) to form a hydrophobic surface. The SiO2 nanoparticles modified with PVDF were uniformly deposited on the outer surface of cotton fabric aided with the robust air flow force from the sprayer. The morphology and chemical structures were characterized by scanning electron microscopy, mapping, atomic force microscopy, X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy. The results indicated that SiO2 nanoparticles were evenly deposited on the surface of cotton fibers and stable interfacial interaction occurred between SiO2 and PVDF molecular chains. The existence of SiO2 could increase the roughness of the fabric surface, which could enhance the water-repellent property of the coated fabrics. Furthermore, the water-repellent property and thermal insulation properties were evaluated via the water contact angle and thermal conductivity tests, respectively, and the results showed that 20 wt.% SiO2/PVDF fabric achieved a desirable level of contact angle, 136.6°, which was the largest water contact angle among all the samples, and the lowest thermal conductivity of 0.033 W/mK, resulting from the existence of SiO2 nanoparticles. Such a fast and simple spray-coating strategy could be widely introduced into asymmetric fabric modification, and such asymmetric fabrics with reasonable water-repellent and thermal insulating outer surfaces could act as candidates in the field of functional garments.

Download Full-text

Synthesis, Hydrophilicity and Micellization of Coil–Brush Polystyrene-b-(polyglycidol-g-polyglycidol) Copolymer—Comparison with Linear Polystyrene-b-Polyglycidol

Polymers ◽

10.3390/polym14020253 ◽

2022 ◽

Vol 14 (2) ◽

pp. 253

Author(s):

Mariusz Gadzinowski ◽

Maciej Kasprów ◽

Teresa Basinska ◽

Stanislaw Slomkowski ◽

Łukasz Otulakowski ◽

...

Keyword(s):

Contact Angle ◽

Self Assembly ◽

Original Method ◽

Critical Micellization Concentration ◽

Water Contact ◽

1H And 13C Nmr ◽

Similar Composition ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Static Conditions

In this paper, an original method of synthesis of coil–brush amphiphilic polystyrene-b-(polyglycidol-g-polyglycidol) (PS-b-(PGL-g-PGL)) block copolymers was developed. The hypothesis that their hydrophilicity and micellization can be controlled by polyglycidol blocks architecture was verified. The research enabled comparison of behavior in water of PS-b-PGL copolymers and block–brush copolymers PS-b-(PGL-g-PGL) with similar composition. The coil–brush copolymers were composed of PS-b-PGL linear core with average DPn of polystyrene 29 and 13 of polyglycidol blocks. The DPn of polyglycidol side blocks of coil–b–brush copolymers were 2, 7, and 11, respectively. The copolymers were characterized by 1H and 13C NMR, GPC, and FTIR methods. The hydrophilicity of films from the linear and coil–brush copolymers was determined by water contact angle measurements in static conditions. The behavior of coil–brush copolymers in water and their critical micellization concentration (CMC) were determined by UV-VIS using 1,6-diphenylhexa-1,3,5-trien (DPH) as marker and by DLS. The CMC values for brush copolymers were much higher than for linear species with similar PGL content. The results of the copolymer film wettability and the copolymer self-assembly studies were related to fraction of hydrophilic polyglycidol. The CMC for both types of polymers increased exponentially with increasing content of polyglycidol.

Download Full-text

Improved de-inking of inkjet-printed paper using environmentally friendly atmospheric pressure low temperature plasma for paper recycling

Scientific Reports ◽

10.1038/s41598-019-50495-4 ◽

2019 ◽

Vol 9 (1) ◽

Author(s):

Rodolphe Mauchauffé ◽

Seung Jun Lee ◽

Isaac Han ◽

Sang Hyeong Kim ◽

Se Youn Moon

Keyword(s):

Plasma Treatment ◽

Atmospheric Pressure ◽

Paper Recycling ◽

Temperature Plasma ◽

Water Contact ◽

Angle Measurements ◽

Natural Energy ◽

Contact Angle Measurements ◽

Speed Up ◽

Uv Visible

Abstract Nowadays, due to environmental pollution and natural energy consumption caused by waste paper, many researches are being conducted on the reuse of printed-paper. To recycle the paper, de-inking has to be performed. In this article, in order to reduce the use of the commonly used de-inking chemicals, the effect of an atmospheric pressure helium plasma treatment on the de-inking enhancement of printed-paper is studied. Through colorimeter and UV-visible spectrometer measurements the plasma treatment is shown to speed up the de-inking. While SEM observations and FTIR measurements suggest that the paper quality is retained upon plasma treatment, the increase of surface hydrophilicity measured by water contact angle measurements, compared to non-treated paper, is believed to enhance the fiber swelling of the paper and lead to a faster ink removal.

Download Full-text

Non-woven Membranes Electrospun from Polylactic Acid Incorporating Silver Nanoparticles as Biocide

MRS Proceedings ◽

10.1557/opl.2012.285 ◽

2012 ◽

Vol 1376 ◽

Cited By ~ 5

Author(s):

Haydee Vargas-Villagran ◽

Elvia Teran-Salgado ◽

Maraolina Dominguez-Diaz ◽

Osvaldo Flores ◽

Bernardo Campillo ◽

...

Keyword(s):

Contact Angle ◽

Silver Nanoparticles ◽

Polylactic Acid ◽

Chloroform Solution ◽

Average Diameter ◽

Electrospinning Process ◽

Water Contact ◽

X Ray Scattering ◽

Angle Measurements ◽

Contact Angle Measurements

ABSTRACTIn this research, we describe the electrospinning processing of polylactic acid (PLA) and the influence of silver nanoparticles on the morphology and microstructure of produced non woven membranes thus produced. The PLA was electrospun from a chloroform solution and a filamentary and granular morphology was obtained, the filaments having an average diameter of 1.25 μm, When silver nanoparticles (of ca. 12 nm size) were incorporated, the filaments diameter was reduced to an average of 0.65 μm, and the density of beads was also reduced. The membranes were rather amorphous, as revealed by X-ray scattering, presumably due to the quenching process associated with the electrospinning process. Water contact angle measurements showed that silver nanoparticles induced significant hidrophobicity in the membranes as neat PLA membrane had a contact angle of 54° and PLA/Ag membrane exhibited an angle of 115°.

Download Full-text

Protection of LiFePO4 against Moisture

Materials ◽

10.3390/ma13040942 ◽

2020 ◽

Vol 13 (4) ◽

pp. 942 ◽

Cited By ~ 1

Author(s):

Nicolas Delaporte ◽

Michel L. Trudeau ◽

Daniel Bélanger ◽

Karim Zaghib

Keyword(s):

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

Atomic Emission ◽

Carbon Surface ◽

Water Contact ◽

Inductively Coupled ◽

Spontaneous Reduction ◽

Angle Measurements ◽

Contact Angle Measurements ◽

Carbon Coated

In this study, a carbon-coated LiFePO4 (LFP/C) powder was chemically grafted with trifluoromethylphenyl groups in order to increase its hydrophobicity and to protect it from moisture. The modification was carried out by the spontaneous reduction of in situ generated 4-trifluoromethylphenyl ions produced by the diazotization of 4-trifluoromethylaniline. X-ray photoelectron spectroscopy was used to analyze the surface organic species of the modified powder. The hydrophobic properties of the modified powder were investigated by carrying out its water contact angle measurements. The presence of the trifluoromethylphenyl groups on the carbon-coated LiFePO4 powder increased its stability in deionized water and reduced its iron dissolution in the electrolyte used for assembling the battery. The thermogravimetric and inductively coupled plasma atomic emission spectroscopy analyses revealed that 0.2–0.3 wt.% Li was deinserted during grafting and that the loading of the grafted molecules varied from 0.5 to 0.8 wt.% depending on the reaction conditions. Interestingly, the electrochemical performance of the modified LFP/C was not adversely affected by the presence of the trifluoromethylphenyl groups on the carbon surface. The chemical relithiation of the grafted samples was carried out using LiI as the reducing agent and the lithium source in order to obtain fully lithiated grafted powders.

Download Full-text

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

Journal of Water Reuse and Desalination ◽

10.2166/wrd.2015.089 ◽

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.

Download Full-text