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Membranes ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 90
Author(s):  
Salar Bahrami ◽  
Leila Dolatyari ◽  
Hassan Shayani-Jam ◽  
Mohammad Reza Yaftian ◽  
Spas D. Kolev

A polymer inclusion membrane (PIM) composed of 50 wt% base polymer poly(vinylidenefluoride-co-hexafluoropropylene), 40 wt% extractant Aliquat® 336, and 10 wt% dibutyl phthalate as plasticizer/modifier provided the efficient extraction of vanadium(V) (initial concentration 50 mg L−1) from 0.1 M sulfate solutions (pH 2.5). The average mass and thickness of the PIMs (diameter 3.5 cm) were 0.057 g and 46 μm, respectively. It was suggested that V(V) was extracted as VO2SO4− via an anion exchange mechanism. The maximum PIM capacity was estimated to be ~56 mg of V(V)/g for the PIM. Quantitative back-extraction was achieved with a 50 mL solution of 6 M H2SO4/1 v/v% of H2O2. It was assumed that the back-extraction process involved the oxidation of VO2+ to VO(O2)+ by H2O2. The newly developed PIM, with the optimized composition mentioned above, exhibited an excellent selectivity for V(V) in the presence of metallic species present in digests of spent alumina hydrodesulfurization catalysts. Co-extraction of Mo(VI) with V(V) was eliminated by its selective extraction at pH 1.1. Characterization of the optimized PIM was performed by contact angle measurements, atomic-force microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis/derivatives thermogravimetric analysis and stress–strain measurements. Replacement of dibutyl phthalate with 2-nitrophenyloctyl ether improved the stability of the studied PIMs.


Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 24
Author(s):  
Abdul Latif Ahmad ◽  
Oluwasola Idowu Ebenezer ◽  
Noor Fazliani Shoparwe ◽  
Suzylawati Ismail

The application of polymer inclusion membranes (PIMs) for the aquatic remediation of several heavy metals, dyes, and nutrients has been extensively studied. However, its application in treating organic compounds such as Ibuprofen, an emerging pharmaceutical contaminant that poses potential environmental problems, has not been explored satisfactorily. Therefore, graphene oxide (GO) doped PIMs were fabricated, characterized, and applied to extract aqueous Ibuprofen at varied pH conditions. The doped PIMs were synthesized using a low concentration of Aliquat 336 as carrier and 0, 0.15, 0.45, and 0.75% GO as nanoparticles in polyvinyl chloride (PVC) base polymer without adding any plasticizer. The synthesized PIM was characterized by SEM, FTIR, physical, and chemical stability. The GO doped PIM was well plasticized and had an optimal Ibuprofen extraction efficiency of about 84% at pH of 10 and 0.75% GO concentration. Furthermore, the GO doped PIM’s chemical stability indicates better stability in acidic solution than in the alkaline solution. This study demonstrates that the graphene oxide-doped PIM significantly enhanced the extraction of Ibuprofen at a low concentration. However, further research is required to improve its stability and efficiency for the remediation of the ubiquitous Ibuprofen in the aquatic environment.


Membranes ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 16
Author(s):  
Elzbieta Radzyminska-Lenarcik ◽  
Kamila Maslowska ◽  
Wlodzimierz Urbaniak

Polymer inclusion membranes (PIMs) are an attractive approach to the separation of metals from an aqueous solution. This study is concerned with the use of 2-alkylimidazoles (alkyl = methyl, ethyl, propyl, butyl) as ion carriers in PIMs. It investigates the separation of copper (II), zinc (II), cobalt (II), and nickel (II) from aqueous solutions with the use of polymer inclusion membranes. PIMs are formed by casting a solution containing a carrier (extractant), a plasticizer (o-NPPE), and a base polymer such as cellulose triacetate (CTA) to form a thin, flexible, and stable film. The topics discussed include transport parameters, such as the type of carrier, initial fluxes, separation coefficients of copper in relation to other metals, as well as transport recovery of metal ions. The membrane was characterized using AFM and SEM to obtain information on its composition.


Polymers ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 4414
Author(s):  
Lorena Sánchez-Ponce ◽  
María Dolores Galindo-Riaño ◽  
María José Casanueva-Marenco ◽  
María Dolores Granado-Castro ◽  
Margarita Díaz-de-Alba

A disposable colour-changeable optical sensor based on an interesting polymer inclusion-membrane (PIM) was designed to determine Cd(II) ions in aqueous medium. The Schiff base 2-acetylpyridine benzoylhydrazone (2-APBH) immobilised on the polymer membrane was used as a sensing molecule. The amounts of the PIM components were optimised by a 32 fractional factorial design with two central points and two blocks. The best optical sensor composition consisted of 2.5 g of poly(vinylchloride) (PVC) as a base polymer, 3 mL of tributyl phosphate (TBP) as a plasticiser, and 0.02 g of 2-APBH as a reagent. The sensor showed a good linear response in the range from 0.02 mg L−1 (limit of detection) to 1 mg L−1 of Cd(II) under the following experimental conditions: pH 9.5 (adjusted using ammonium chloride buffer solution at 0.337 mol L−1), 60 min of exposure time plus 2 min of sonication (pulses at 2 s intervals), and 10 min of short-term stability. The relative standard deviation of the method was determined to be 4.04% for 0.4 mg L−1 of Cd(II). The optical sensor was successfully applied to the determination of Cd(II) in natural-water and art-paint samples.


Author(s):  
Salar Bahrami ◽  
Leila Dolatyari ◽  
Hassan Shayani-Jam ◽  
Mohammad Reza Yaftian ◽  
Spas D. Kolev

A polymer inclusion membrane (PIM) composed of 50 wt% poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) as its base polymer, 40 wt% Aliquat® 336 as its extractant and 10 wt% dibutyl phthalate (DBP) as plasticizer provided efficient extraction of vanadium(V) from its sulfate solutions adjusted to pH 2.5. It was suggested that V(V) was extracted as VO2SO4− via an anion exchange mechanism. Quantitative back-extraction was achieved in a sulfuric acid solution (6 mol L-1) containing 1 v/v% of hydrogen peroxide. It was assumed that the back-extraction process involved the oxidation of VO2+ to VO(O2)+ by hydrogen peroxide. The newly developed PIM with the optimized composition mentioned above exhibited excellent selectivity for V(V) in the presence of metallic species present in digests of spent alumina hydrodesulfurization catalysts (i.e., Al(III), Co(II), Cu(II), Fe(III), Mn(II), and Ni(II)). The co-extraction of Mo(VI) with V(V) was eliminated by its selective extraction at pH 1.1. The optimized PIM was characterized by contact angle measurements, atomic-force microscopy (AFM), energy dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA)/derivatives thermogravimetric analysis (DTGA), and the stress-strain measurements.


2021 ◽  
Vol 513 ◽  
pp. 230539
Author(s):  
Jun Woo Jeon ◽  
Dong-Min Kim ◽  
Jinyoung Lee ◽  
Min Su Kim ◽  
Min Ho Jeon ◽  
...  

2021 ◽  
Vol 37 (5) ◽  
pp. 1002-1016
Author(s):  
Satish Kumar ◽  
Shayoraj Shayoraj ◽  
Neeru Devi ◽  
Santosh Kumar Dubey ◽  
Ashwani Kumar ◽  
...  

Acrylic polymer latex has versatile role in many academic and industrial applications like paint, adhesives, textile, paper industry, concrete, surface coating, synthetic rubber and many ones. Acrylic base polymer latex can be prepared by various polymerization methods like Batch emulsion, Seeded emulsion, Situ miniemulsion, Atom transfer radical, Free radical copolymerization, Pickering miniemulsion, Semi-continuous seeded emulsion, dispersion copolymerization, aqueous suspension polymerization etc. in different solvents i.e. 1,1,2-trichloroethane, water, deionized water, 1,4-dioxane, chloroform, tetra hydro furan, toluene, benzene, nitric acid and so on. Acrylic latexes possessed various properties such as increased particle size which resist centrifugal nature and reduce viscosity of heavy oil, layered coating on steel improve lustre along with flexibility, tensile strength and thermal stability too. Acrylic latexes increase silicon intensity in silicon nanoparticles by controlling pH of emulsion during polymerization and also super paramagnetic behaviour of Fe2O3 nanocomposites latex controlled by pH. In this connection, many researchers have synthesized various acrylic base polymer latex or its composites, investigate its utility in different forms for different purposes to improve properties as required. In this review our main emphasis is to investigate the synthesis, characterisation and application of various acrylate polymer latexes.


2021 ◽  
Vol 9 ◽  
Author(s):  
Sen Kong ◽  
Rui Wang ◽  
Shengyu Feng ◽  
Dengxu Wang

The construction of silicone elastomers crosslinked by a natural crosslinker under a catalyst-free method is highly desirable. Herein we present catalyst-free silicone elastomers (SEs) by simply introducing tannic acid (TA) as a natural crosslinker when using poly (aminopropylmethylsiloxane-co-dimethylsiloxane) (PAPMS) as the base polymer. The crosslinked bonding of these SEs can be easily changed from hydrogen bonding to covalent bonding by altering the curing reaction from room temperature to heating condition. The formability and mechanical properties of the SEs can be tuned by altering various factors, including processing technique, the amount of TA and aminopropyl-terminated polydimethylsiloxane, the molecular weight and -NH2 content of PAPMS, and the amount of reinforcing filler. The hydrogen bonding was proved by the reversible crosslinking of the elastomers, which can be gradually dissolved in tetrahydrofuran and re-formed after removing the solvent. The covalent bonding was proved by a model reaction of catechol and n-decylamine and occurred through a combination of hydroxylamine reaction and Michael addition reaction. These elastomers exhibit good thermal stability and excellent hydrophobic property and can bond iron sheets to hold the weight of 500 g, indicating their promising as adhesives. These results reveal that TA as a natural product is a suitable “green” crosslinker for the construction of catalyst-free silicone elastomers by a simple crosslinking strategy. Under this strategy, TA and more natural polyphenols could be certainly utilized as crosslinkers to fabricate more organic elastomers by selecting amine-containing polymers and further explore their extensive applications in adhesives, sealants, insulators, sensors, and so forth.


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