1
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Mamba PP, Msagati TAM, Mamba BB, Motsa MM, Nkambule TTI. The removal of pathogenic bacteria and dissolved organic matter from freshwater using microporous membranes: insights into biofilm formation and fouling reversibility. BIOFOULING 2024:1-17. [PMID: 38639133 DOI: 10.1080/08927014.2024.2339438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 04/01/2024] [Indexed: 04/20/2024]
Abstract
Pathogenic bacteria in drinking-water pose a health risk to consumers, as they compromise the quality of portable water. Chemical disinfection of water containing dissolved organic matter (DOM) causes harmful disinfection by-products. In this work, 4-hydroxybenzoic acid (4-HBA) blended polyethersulfone membranes were fabricated and characterised using microscopic and spectroscopic techniques. The membranes were evaluated for the removal of bacteria and DOM from synthetic and environmental water. Permeate flux increased from 287.30 to 374.60 l m-2 h-1 at 3 bars when 4-HBA increased from 0 to 1.5 wt.%, suggesting that 4-HBA influenced the membrane's affinity for water. Furthermore, 4-HBA demonstrated antimicrobial properties by inhibiting bacterial growth. The membrane with 1 wt.% 4-HBA recorded 99.4 and 100% bacteria removal in synthetic and environmental water, respectively. Additionally, DOM removal of 55-73% was achieved. A flux recovery ratio (FRR) of 94.6% was obtained when a mixture of bacteria and humic acid was filtered, implying better fouling layer reversibility during cleaning. Furthermore, 100% FRR was achieved when a multimedia granular filtration step was installed prior to membrane filtration. The results illustrated that the membranes had a high permeate flux with low irreversible fouling. This indicated the potential of the membranes in treating complex feed streams using simple cleaning protocols.
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Affiliation(s)
- Phumlile P Mamba
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
| | - Titus A M Msagati
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
| | - Bhekie B Mamba
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
| | - Machawe M Motsa
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
| | - Thabo T I Nkambule
- Institute for Nanotechnology and Water Sustainability (iNanoWS), College of Science, Engineering and Technology, University of South Africa, Science Campus, Florida, Johannesburg, South Africa
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2
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Zubair M, Yasir M, Ponnamma D, Mazhar H, Sedlarik V, Hawari AH, Al-Harthi MA, Al-Ejji M. Recent advances in nanocellulose-based two-dimensional nanostructured membranes for sustainable water purification: A review. Carbohydr Polym 2024; 329:121775. [PMID: 38286528 DOI: 10.1016/j.carbpol.2024.121775] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2023] [Revised: 12/02/2023] [Accepted: 01/01/2024] [Indexed: 01/31/2024]
Abstract
Nanocellulose (NC), a one-dimensional nanomaterial, is considered a sustainable material for water and wastewater purification because of its promising hydrophilic surface and mechanical characteristics. In this regard, nanostructured membranes comprising NC and two-dimensional (2D) nanomaterials emerged as advanced membranes for efficient and sustainable water purification. This article critically reviews the recent progress on NC-2D nanostructured membranes for water and wastewater treatment. The review highlights the main techniques employed to fabricate NC-2D nanostructured membranes. The physicochemical properties, including hydrophilicity, percent porosity, surface roughness, structure, and mechanical and thermal stability, are summarized. The key performance indicators such as permeability, rejection, long operation stability, antifouling, and interaction mechanisms are thoroughly discussed to evaluate the role of NC and 2D nanomaterials. Finally, summary points and future development work are highlighted to overcome the challenges for potential practical applications. This review contributes to the design and development of advanced membranes to solve growing water pollution concerns in a sustainable manner.
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Affiliation(s)
- Mukarram Zubair
- Department of Environmental Engineering, College of Engineering, Imam Abdulrahman Bin Faisal University, P.O. Box 1982, Dammam 31451, Saudi Arabia.
| | - Muhammad Yasir
- Centre of Polymer Systems, University Institute, Tomas Bata University in Zlín, Třída Tomáše Bati 5678, 76001 Zlín, Czech Republic
| | - Deepalekshmi Ponnamma
- Materials Science and Technology Program, College of Arts and Sciences, Qatar University, P.O. Box 2713, Doha, Qatar
| | - Hassam Mazhar
- Department of Chemical Engineering, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia
| | - Vladimir Sedlarik
- Centre of Polymer Systems, University Institute, Tomas Bata University in Zlín, Třída Tomáše Bati 5678, 76001 Zlín, Czech Republic
| | - Alaa H Hawari
- Department of Civil and Architectural Engineering, College of Engineering, Qatar University, P.O. Box 2713, Doha, Qatar
| | - Mamdouh Ahmed Al-Harthi
- Department of Chemical Engineering, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia; Interdisciplinary Research Center for Refining & Advanced Chemicals, King Fahd University of Petroleum & Minerals, 31261, Dhahran, Saudi Arabia
| | - Maryam Al-Ejji
- Center for Advanced Materials, Qatar University, P.O. Box 2713, Doha, Qatar.
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3
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Goyat R, Singh J, Umar A, Saharan Y, Ibrahim AA, Akbar S, Baskoutas S. Enhancing oil-water emulsion separation via synergistic filtration using graphene oxide-silver oxide nanocomposite-embedded polyethersulfone membrane. WASTE MANAGEMENT & RESEARCH : THE JOURNAL OF THE INTERNATIONAL SOLID WASTES AND PUBLIC CLEANSING ASSOCIATION, ISWA 2024:734242X231223914. [PMID: 38366790 DOI: 10.1177/0734242x231223914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/18/2024]
Abstract
This study introduces an innovative approach for enhancing oil-water emulsion separation using a polyethersulfone (PES) membrane embedded with a nanocomposite of graphene oxide (GO) and silver oxide (AgO). The composite membrane, incorporating PES and polyvinyl chloride (PVC), demonstrates improved hydrophilicity, structural integrity and resistance to fouling. Physicochemical characterization confirms successful integration of GO and AgO, leading to increased tensile strength, porosity and hydrophilicity. Filtration tests reveal substantial improvements in separating various oils from contaminated wastewater, with the composite membrane exhibiting superior efficiency and reusability compared to pristine PES membranes. This research contributes to the development of environmentally friendly oil-water separation methods with broad industrial applications.
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Affiliation(s)
- Rohit Goyat
- Department of Chemistry, Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala, Haryana, India
| | - Joginder Singh
- Department of Chemistry, Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala, Haryana, India
| | - Ahmad Umar
- Department of Chemistry, College of Science and Arts, and Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran, Kingdom of Saudi Arabia
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA
| | - Yajvinder Saharan
- Department of Chemistry, Maharishi Markandeshwar (Deemed to be University), Mullana, Ambala, Haryana, India
| | - Ahmed A Ibrahim
- Department of Chemistry, College of Science and Arts, and Promising Centre for Sensors and Electronic Devices (PCSED), Najran University, Najran, Kingdom of Saudi Arabia
| | - Sheikh Akbar
- Department of Materials Science and Engineering, The Ohio State University, Columbus, OH, USA
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4
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Man GT, Albu PC, Nechifor AC, Grosu AR, Popescu (Stegarus) DI, Grosu VA, Marinescu VE, Nechifor G. Simultaneously Recovery of Thorium and Tungsten through Hybrid Electrolysis-Nanofiltration Processes. TOXICS 2024; 12:103. [PMID: 38393198 PMCID: PMC10892189 DOI: 10.3390/toxics12020103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 01/13/2024] [Accepted: 01/23/2024] [Indexed: 02/25/2024]
Abstract
The recovery and recycling of metals that generate toxic ions in the environment is of particular importance, especially when these are tungsten and, in particular, thorium. The radioactive element thorium has unexpectedly accessible domestic applications (filaments of light bulbs and electronic tubes, welding electrodes, and working alloys containing aluminum and magnesium), which lead to its appearance in electrical and electronic waste from municipal waste management platforms. The current paper proposes the simultaneous recovery of waste containing tungsten and thorium from welding electrodes. Simultaneous recovery is achieved by applying a hybrid membrane electrolysis technology coupled with nanofiltration. An electrolysis cell with sulphonated polyether-ether-ketone membranes (sPEEK) and a nanofiltration module with chitosan-polypropylene membranes (C-PHF-M) are used to carry out the hybrid process. The analysis of welding electrodes led to a composition of W (tungsten) 89.4%; Th 7.1%; O2 2.5%; and Al 1.1%. Thus, the parameters of the electrolysis process were chosen according to the speciation of the three metals suggested by the superimposed Pourbaix diagrams. At a constant potential of 20.0 V and an electrolysis current of 1.0 A, the pH is varied and the possible composition of the solution in the anodic workspace is analyzed. Favorable conditions for both electrolysis and nanofiltration were obtained at pH from 6 to 9, when the soluble tungstate ion, the aluminum hydroxide, and solid thorium dioxide were formed. Through the first nanofiltration, the tungstate ion is obtained in the permeate, and thorium dioxide and aluminum hydroxide in the concentrate. By adding a pH 13 solution over the two precipitates, the aluminum is solubilized as sodium aluminate, which will be found after the second nanofiltration in the permeate, with the thorium dioxide remaining integrally (within an error of ±0.1 ppm) on the C-PHF-M membrane.
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Affiliation(s)
- Geani Teodor Man
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania; (G.T.M.); (A.C.N.); (A.R.G.)
- National Research and Development Institute for Cryogenics and Isotopic Technologies–ICSI, 240050 Râmnicu Valcea, Romania;
| | - Paul Constantin Albu
- Radioisotopes and Radiation Metrology Department (DRMR), IFIN Horia Hulubei, 023465 Măgurele, Romania;
| | - Aurelia Cristina Nechifor
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania; (G.T.M.); (A.C.N.); (A.R.G.)
| | - Alexandra Raluca Grosu
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania; (G.T.M.); (A.C.N.); (A.R.G.)
| | | | - Vlad-Alexandru Grosu
- Department of Electronic Technology and Reliability, Faculty of Electronics, Telecommunications and Information Technology, University Politehnica of Bucharest, 061071 Bucharest, Romania
| | - Virgil Emanuel Marinescu
- Department of Physical-Chemical Tests, National Institute for Research and Development in Electrical Engineering ICPE–CA Bucharest, 030138 Bucharest, Romania;
| | - Gheorghe Nechifor
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania; (G.T.M.); (A.C.N.); (A.R.G.)
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5
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Maqbool A, Shahid A, Jahan Z, Bilal Khan Niazi M, Ali Inam M, Tawfeek AM, M Kamel E, Saeed Akhtar M. Development of ZnO-GO-NiO membrane for removal of lead and cadmium heavy metal ions from wastewater. CHEMOSPHERE 2023; 338:139622. [PMID: 37487982 DOI: 10.1016/j.chemosphere.2023.139622] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 07/19/2023] [Accepted: 07/21/2023] [Indexed: 07/26/2023]
Abstract
The presence of heavy metal (HM) ions, such as lead, cadmium, and chromium in industrial wastewater discharge are major contaminants that pose a risk to human health. These HMs should separate from the wastewater to ensure the reuse of the discharged water in the process and mitigate their environmental impacts. The distinctive mechanical properties of 2D graphene oxide (GO), and the antifouling characteristics of metal oxides (ZnO/NiO) nanoparticles combined to produce composites supporting special features for wastewater treatment. This study employed solution casting and phase inversion methods to synthesize PSF-based GO, ZnO-GO, and ZnO-GO-NiO mixed matrix membranes and the effects of variation in composition on the removal of lead (Pb2+) and cadmium (Cd2+) ion was examined. Several characterization techniques including X-ray diffraction analysis, scanning electron microscopy, energy dispersive X-ray, and Fourier transform infrared spectroscopy were applied to analyze the synthesized NPs and MMMs. The composite membranes were also analyzed in terms of their porosity, permeability, hydrophilicity, surface roughness, zeta potential, thermal stability, mechanical strength, and flux regeneration at various transmembrane pressures (2-3 kgcm-2), and pH value (5.5). The highest adsorption capacities were measured to be 308.16 mg g-1 and 354.80 mg g-1 for Pb (II) and Cd (II), respectively, for membrane (M4_A) having 0.3 wt% of ZnO-GO-NiO nanocomposite, at 200 mg L-1 of feed concentration and 1.60 mL min-1 of permeate flux. The Pb (II) and Cd (II) adsorption breakthrough curves were created, and the results of the experiment were compared with the data of the Thomas model.
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Affiliation(s)
- Arslan Maqbool
- Department of Chemical Engineering, School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad, 44000, Pakistan
| | - Ameen Shahid
- Department of Chemical Engineering, School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad, 44000, Pakistan.
| | - Zaib Jahan
- Department of Chemical Engineering, School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad, 44000, Pakistan.
| | - Muhammad Bilal Khan Niazi
- Department of Chemical Engineering, School of Chemical and Materials Engineering, National University of Sciences and Technology, Islamabad, 44000, Pakistan
| | - Muhammad Ali Inam
- Institute of Environmental Sciences & Engineering (IESE), School of Civil and Environmental Engineering (SCEE), National University of Sciences and Technology (NUST), Islamabad, Pakistan
| | - Ahmed M Tawfeek
- Chemistry Department, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Emadeldin M Kamel
- Chemistry Department, Faculty of Science, Beni-Suef University, Beni-Suef, 62514, Egypt
| | - Muhammad Saeed Akhtar
- School of Chemical Engineering, Yeungnam University, Gyeongsan, 712-749, Republic of Korea.
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6
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Tu R, Kim HC, Sodano HA. Additive Manufacturing of High-Temperature Thermoplastic Polysulfone with Tailored Microstructure via Precipitation Printing. ACS APPLIED MATERIALS & INTERFACES 2023; 15:45270-45280. [PMID: 37698842 DOI: 10.1021/acsami.3c09048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/13/2023]
Abstract
Current additive manufacturing processes for polymers, including material extrusion, vat photopolymerization, material jetting, and powder bed fusion, have limitations in manufacturing high-temperature thermoplastics including narrow material selection, compromised mechanical properties, and potential degradation of materials during processing. Polysulfone (PSU) is a high-temperature thermoplastic with outstanding chemical resistance, flame retardancy, and toughness. However, besides injection molding, additive manufacturing of PSU has only been achieved through extrusion or solvent-cast three-dimensional (3D) printing without obtaining high mechanical properties. In this work, precipitation printing is applied to fabricate high-temperature thermoplastics such as PSU for the first time, where tailoring of the microstructure and mechanical properties is enabled through control of solvents and printing parameters. The printed PSU can either be dense and strong with 2.47 GPa Young's modulus and 70.6 MPa tensile strength or porous and highly anisotropic. After drying at a maximum temperature of 190 °C, both the printed dense and porous PSU samples have a glass-transition temperature of about 200 °C, which allows them to be used in high-temperature environments. Thus, precipitation printing provides an alternative approach to manufacture high-temperature thermoplastics like PSU with scalability and tailorable properties.
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Affiliation(s)
- Ruowen Tu
- Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Hyun Chan Kim
- Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Henry A Sodano
- Department of Aerospace Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Materials Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
- Department of Macromolecular Science and Engineering, University of Michigan, Ann Arbor, Michigan 48109, United States
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7
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Pașcu D, Nechifor AC, Grosu VA, Oprea OC, Tanczos SK, Man GT, Dumitru F, Grosu AR, Nechifor G. Hydrogen Sulphide Sequestration with Metallic Ions in Acidic Media Based on Chitosan/sEPDM/Polypropylene Composites Hollow Fiber Membranes System. MEMBRANES 2023; 13:350. [PMID: 36984736 PMCID: PMC10057485 DOI: 10.3390/membranes13030350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 03/10/2023] [Accepted: 03/14/2023] [Indexed: 06/18/2023]
Abstract
This paper presents the preparation and characterization of composite membranes based on chitosan (Chi), sulfonated ethylene-propylene-diene terpolymer (sEPDM), and polypropylene (PPy), and designed to capture hydrogen sulfide. The Chi/sEPDM/PPy composite membranes were prepared through controlled evaporation of a toluene dispersion layer of Chi:sEPDM 1;1, w/w, deposited by immersion and under a slight vacuum (100 mmHg) on a PPy hollow fiber support. The composite membranes were characterized morphologically, structurally, and thermally, but also from the point of view of their performance in the process of hydrogen sulfide sequestration in an acidic media solution with metallic ion content (Cu2+, Cd2+, Pb2+, and/or Zn2+). The operational parameters of the pertraction were the pH, pM, matrix gas flow rate, and composition. The results of pertraction from synthetic gases mixture (nitrogen, methane, carbon dioxide) indicated an efficient removal of hydrogen sulfide through the prepared composite membranes, as well as its immobilization as sulfides. The sequestration and the recuperative separation, as sulfides from an acid medium, of the hydrogen sulfide reached up to 96%, decreasing in the order: CuS > PbS > CdS > ZnS.
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Affiliation(s)
- Dumitru Pașcu
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Aurelia Cristina Nechifor
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Vlad-Alexandru Grosu
- Department of Electronic Technology and Reliability, Faculty of Electronics, Telecommunications and Information Technology, University Politehnica of Bucharest, 061071 Bucharest, Romania
| | - Ovidiu Cristian Oprea
- Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Szidonia-Katalin Tanczos
- Department of Bioengineering, University Sapientia of Miercurea-Ciuc, 500104 Miercurea-Ciuc, Romania
| | - Geani Teodor Man
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Florina Dumitru
- Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Alexandra Raluca Grosu
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Gheorghe Nechifor
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
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8
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Păncescu FM, Rikabi AAKK, Oprea OC, Grosu AR, Nechifor AC, Grosu VA, Tanczos SK, Dumitru F, Nechifor G, Bungău SG. Chitosan-sEPDM and Melatonin-Chitosan-sEPDM Composite Membranes for Melatonin Transport and Release. MEMBRANES 2023; 13:282. [PMID: 36984671 PMCID: PMC10057635 DOI: 10.3390/membranes13030282] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 02/25/2023] [Indexed: 06/18/2023]
Abstract
Melatonin is the hormone that focuses the attention of the researchers in the medical, pharmaceutical, materials, and membranes fields due to its multiple biomedical implications. The variety of techniques and methods for the controlled release of melatonin is linked to the multitude of applications, among which sports medicine occupies a special place. This paper presents the preparation and characterization of composite membranes based on chitosan (Chi) and sulfonated ethylene-propylene-diene terpolymer (sEPDM). The membranes were obtained by controlled vacuum evaporation from an 8% sEPDM solution in toluene (w/w), in which chitosan was dispersed in an ultrasonic field (sEPDM:Chi = 1:1, w/w). For the comparative evaluation of the membranes' performances, a melatonin-chitosan-sulfonated ethylene-propylene-diene terpolymer (Mel:Chi:sEPDM = 0.5:0.5:1.0, w/w/w) test membrane was made. The prepared membranes were morphologically and structurally characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), energy-dispersive spectroscopy analysis (EDAX), thermal analysis (TG, DSC), thermal analysis coupled with chromatography and infrared analysis, and contact angle measurements, but also from the point of view of performance in the process of transport and release of melatonin in dedicated environments (aqueous solutions with controlled pH and salinity). The prepared membranes can release melatonin in amounts between 0.4 mg/cm2·per day (sEPDM), 1.6 mg/ cm2·per day (Chi/sEPDM), and 1.25 mg/cm2·per day (Mel/Chi/SEPDM).
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Affiliation(s)
- Florentina Mihaela Păncescu
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Abbas Abdul Kadhim Klaif Rikabi
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
- Al–Mussaib Technical College, Al–Furat Al–Awsat Technical University (ATU), Babylon–Najaf Street, Kufa 54003, Iraq
| | - Ovidiu Cristian Oprea
- Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Alexandra Raluca Grosu
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Aurelia Cristina Nechifor
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Vlad-Alexandru Grosu
- Department of Electronic Technology and Reliability, Faculty of Electronics, Telecommunications and Information Technology, University Politehnica of Bucharest, 061071 Bucharest, Romania
| | - Szidonia-Katalin Tanczos
- Department of Bioengineering, University Sapientia of Miercurea-Ciuc, 500104 Miercurea-Ciuc, Romania
| | - Florina Dumitru
- Department of Inorganic Chemistry, Physical Chemistry and Electrochemistry, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Gheorghe Nechifor
- Analytical Chemistry and Environmental Engineering Department, University Politehnica of Bucharest, 011061 Bucharest, Romania
| | - Simona Gabriela Bungău
- Department of Pharmacy, Faculty of Medicine and Pharmacy, University of Oradea, 410028 Oradea, Romania
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9
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Zambrano-Intriago LA, Amorim CG, Araújo AN, Gritsok D, Rodríguez-Díaz JM, Montenegro MCBSM. Development of an inexpensive and rapidly preparable enzymatic pencil graphite biosensor for monitoring of glyphosate in waters. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 855:158865. [PMID: 36165910 DOI: 10.1016/j.scitotenv.2022.158865] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 09/11/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
Glyphosate (GLY) is the most widely used non-selective broad-spectrum herbicide worldwide under well-reported side effects on the environment and human health. That's why it's necessary to control its presence in the environment. This work describes the development of an affordable, simple, and accurate electrochemical biosensor using a pencil graphite electrode as support, a horseradish peroxidase enzyme immobilized on a polysulfone membrane doped with multi-walled carbon nanotubes. The developed electrochemical sensor was used in the determination of GLY in river and drinking water samples. Cyclic voltammetry and amperometry were used as electrochemical detection techniques for the characterization and analytical application of the developed biosensor. The working mechanism of the biosensor is based on the inhibition of the peroxidase enzyme by GLY. Under optimal experimental conditions, the biosensor showed a linear response in the concentration range of 0.1 to 10 mg L-1. The limits of detection and quantification are 0.025 ± 0.002 and 0.084 ± 0.007 mg L-1, respectively, which covers the maximum residual limit established by the EPA for drinking water (0.7 mg L-1). The proposed biosensor demonstrated high reproducibility, excellent analytical performance, repeatability, and accuracy. The sensor proved to be selective against other pesticides, organic acids, and inorganic salts. Application on real samples showed recovery rates ranging between 98.18 ± 0.11 % and 97.32 ± 0.23 %. The analytical features of the proposed biosensor make it an effective and useful tool for the detection of GLY for environmental analysis.
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Affiliation(s)
- Luis Angel Zambrano-Intriago
- LAQV-REQUIMTE/Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal; Laboratorio de Análisis Químicos y Biotecnológicos, Instituto de Investigación, Universidad Técnica de Manabí, Portoviejo 130105, Ecuador
| | - Célia G Amorim
- LAQV-REQUIMTE/Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
| | - Alberto N Araújo
- LAQV-REQUIMTE/Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Dmitrij Gritsok
- LAQV-REQUIMTE/Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Joan Manuel Rodríguez-Díaz
- Laboratorio de Análisis Químicos y Biotecnológicos, Instituto de Investigación, Universidad Técnica de Manabí, Portoviejo 130105, Ecuador; Departamento de Procesos Químicos, Facultad de Ciencias Matemáticas, Físicas y Químicas, Universidad Técnica de Manabí, Portoviejo 130105, Ecuador.
| | - Maria C B S M Montenegro
- LAQV-REQUIMTE/Departamento de Ciências Químicas, Faculdade de Farmácia, Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
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10
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Development and optimization of low surface free energy of rGO-PVDF mixed matrix membrane for membrane distillation. Sep Purif Technol 2023. [DOI: 10.1016/j.seppur.2022.122428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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11
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Nain A, Sangili A, Hu SR, Chen CH, Chen YL, Chang HT. Recent progress in nanomaterial-functionalized membranes for removal of pollutants. iScience 2022; 25:104616. [PMID: 35789839 PMCID: PMC9250028 DOI: 10.1016/j.isci.2022.104616] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Membrane technology has gained tremendous attention for removing pollutants from wastewater, mainly due to their affordable capital cost, miniature equipment size, low energy consumption, and high efficiency even for the pollutants present in lower concentrations. In this paper, we review the literature to summarize the progress of nanomaterial-modified membranes for wastewater treatment applications. Introduction of nanomaterial in the polymeric matrix influences membrane properties such as surface roughness, hydrophobicity, porosity, and fouling resistance. This review also covers the importance of functionalization strategies to prepare thin-film nanocomposite hybrid membranes and their effect on eliminating pollutants. Systematic discussion regarding the impact of the nanomaterials incorporated within membrane, toward the recovery of various pollutants such as metal ions, organic compounds, dyes, and microbes. Successful examples are provided to show the potential of nanomaterial-functionalized membranes for regeneration of wastewater. In the end, future prospects are discussed to develop nanomaterial-based membrane technology.
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Affiliation(s)
- Amit Nain
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Arumugam Sangili
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Shun-Ruei Hu
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
| | - Chun-Hsien Chen
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807378, Taiwan
| | - Yen-Ling Chen
- School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807378, Taiwan
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chia-Yi 621301, Taiwan
- Department of Fragrance and Cosmetic Science, College of Pharmacy, Kaohsiung Medical University, Kaohsiung 807378, Taiwan
- Corresponding author
| | - Huan-Tsung Chang
- Department of Chemistry, National Taiwan University, Taipei 10617, Taiwan
- Corresponding author
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Tasci RO, Kaya MA, Celebi M. Hydrophilicity and flux properties improvement of high performance polysulfone membranes via sulfonation and blending with Poly(lactic acid). HIGH PERFORM POLYM 2022. [DOI: 10.1177/09540083221110031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
To achieve increased flow and reduce fouling, polymeric membranes can be functionalized with hydrophilic groups such as sulfone, amines, and others. This research has aimed at the sulfonation of Polysulfone (PSU) with various agents and at varying substitution degrees to change its hydrophobic character. PSU was also blended with Poly(lactic acid) (PLA), which is a more hydrophilic polymer. The phase inversion method was used to make PSU, PLA, sulfonated PSU, and PSU/PLA blend-based membranes. Sulfonation degrees of sulfonated PSU membranes were assessed using FT-IR, mechanical characteristics of membranes were determined, and thermal properties of membranes were clarified using DSC and TGA techniques. Hydrophilic natures and membrane alterations were investigated, as well as contact angle and water uptake measures. Among three distinct sulfonation agents (trimethylsilyl chlorosulfonate (TMSCS), sulfuric acid, and chlorosulfonic acid) employed to produce a 20% sulfonation degree of polysulfone, TMSCS was chosen as having the highest sulfonation efficiency (91.5%). With increasing sulfonation degree, a drop in molecular weight was seen in all sulfonated polysulfone samples. The mechanical strength values of polysulfone after sulfonation with TMSCS rose from 35.23 MPa to 63.35 MPa, while the contact angle value decreased from 85.58° to 71°. The contact angle value reduced from 85.58° to 64.68° while the mechanical strength of the PSU and PSU/PLA (50:50) blend increased from 35.23 MPa to 39.3 MPa. Membranes were also tested for pure water flux, hydrostability, and biostability. In terms of application requirements, it was determined that sulfonated PSU-based membranes manufactured with TMSCS with a 20% sulfonation degree and PSU/PLA blend-based membranes with a 50:50 (w:w) ratio have the optimum compositions with high flux quantities.
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Affiliation(s)
- Reyhan O Tasci
- Polymer Materials Engineering, Institute of Graduate Studies, Yalova University, Yalova, Turkey
- Department of Polymer Materials Engineering, Faculty of Engineering, Yalova University, Yalova, Turkey
| | - Mehmet A Kaya
- Department of Polymer Materials Engineering, Faculty of Engineering, Yalova University, Yalova, Turkey
| | - Mithat Celebi
- Department of Polymer Materials Engineering, Faculty of Engineering, Yalova University, Yalova, Turkey
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Simultaneous Release of Silver Ions and 10–Undecenoic Acid from Silver Iron–Oxide Nanoparticles Impregnated Membranes. MEMBRANES 2022; 12:membranes12060557. [PMID: 35736264 PMCID: PMC9227798 DOI: 10.3390/membranes12060557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 05/01/2022] [Accepted: 05/23/2022] [Indexed: 01/27/2023]
Abstract
The bio-medical benefits of silver ions and 10–undecenoic acid in various chemical-pharmaceutical preparations are indisputable, thus justifying numerous research studies on delayed and/or controlled release. This paper presents the effect of the polymer matrix in the simultaneous release of silver ions and 10–undecenoic acid in an aqueous medium of controlled pH and ionic strength. The study took into consideration polymeric matrices consisting of cellulose acetate (CA) and polysulfone (PSf), which were impregnated with oxide nanoparticles containing silver and 10–undecenoic acid. The studied oxide nanoparticles are nanoparticles of iron and silver oxides obtained by an accessible electrochemical method. The obtained results show that silver can be released, simultaneously with 10–undecenoic acid, from an impregnated polymeric membrane, at concentrations that ensure the biocidal and fungicidal capacity. Concentrations of active substances can be controlled by choosing the polymer matrix or, in some cases, by changing the pH of the target medium. In the studied case, higher concentrations of silver ions are released from the polysulfone matrix, while higher concentrations of 10–undecenoic acid are released from the cellulose acetate matrix. The results of the study show that a correlation can be established between the two released target substances, which is dependent on the solubility of the organic compound in the aqueous medium and the interaction of this compound with the silver ions. The ability of 10–undecenoic acid to interact with the silver ion, both through the carboxyl and alkene groups, contributes to the increase in the content of the silver ions transported in the aqueous medium.
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14
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Nanomaterials for Membranes, Membrane Reactors, and Catalyst Systems. NANOMATERIALS 2022; 12:nano12060964. [PMID: 35335777 PMCID: PMC8952564 DOI: 10.3390/nano12060964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 03/03/2022] [Indexed: 02/05/2023]
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15
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New Membrane-Forming Aromatic Co-Poly(amide-imide)s: Influence of the Chemical Structure on the Morphological, Thermal and Transport Properties. MEMBRANES 2022; 12:membranes12010091. [PMID: 35054617 PMCID: PMC8781751 DOI: 10.3390/membranes12010091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 12/31/2021] [Accepted: 01/05/2022] [Indexed: 11/17/2022]
Abstract
Polymer film membranes are used to solve specific separation problems that dictate structural requirements. Structural and morphological parameters of film membranes based on glassy polyheteroarylenes can be controlled in the process of preparation from solutions that opens up prospects for obtaining structured membranes required for targeted separation. In the case of aromatic poly(amide-imide)s, the possibility of controlling film formation and structure virtually has not been studied. In the present work, a series of homologous co-poly(amide-imide)s differing in the number of repeating units with carboxyl-substituted aromatic fragments was synthesized by polycondensation. Comparative analysis of the processes of formation of membranes with different morphologies based on these polymers under equal conditions was performed. New information was obtained about the influence of the amounts of carboxyl groups and the residual solvent on structural properties of asymmetric membranes. The influence of these factors on transport properties of dense membranes under pervaporation conditions was studied. It was demonstrated that in the case of carboxyl-containing poly(amide-imide)s, the domains formed during film preparation had a significant effect on membrane properties.
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Maggay IVB, Aini HN, Lagman MMG, Tang SH, Aquino RR, Chang Y, Venault A. A Biofouling Resistant Zwitterionic Polysulfone Membrane Prepared by a Dual-Bath Procedure. MEMBRANES 2022; 12:69. [PMID: 35054595 PMCID: PMC8780878 DOI: 10.3390/membranes12010069] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 12/31/2021] [Accepted: 01/02/2022] [Indexed: 01/06/2023]
Abstract
This study introduces a zwitterionic material to modify polysulfone (PSf) membranes formed by a dual bath procedure, in view of reducing their fouling propensity. The zwitterionic copolymer, derived from a random polymer of styrene and 4-vinylpyrridine and referred to as zP(S-r-4VP), was incorporated to the PSf solution without any supplementary pore-forming additive to study the effect of the sole copolymer on membrane-structuring, chemical, and arising properties. XPS and mapping FT-IR provided evidence of the modification. Macrovoids appeared and then disappeared as the copolymer content increased in the range 1-4 wt%. The copolymer has hydrophilic units and its addition increases the casting solution viscosity. Both effects play an opposite role on transfers, and so on the growth of macrovoids. Biofouling tests demonstrated the efficiency of the copolymer to mitigate biofouling with a reduction in bacterial and blood cell attachment by more than 85%. Filtration tests revealed that the permeability increased by a twofold factor, the flux recovery ratio was augmented from 40% to 63% after water/BSA cycles, and irreversible fouling was reduced by 1/3. Although improvements are needed, these zwitterionic PSf membranes could be used in biomedical applications where resistance to biofouling by cells is a requirement.
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Affiliation(s)
- Irish Valerie B. Maggay
- R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung-Li 32023, Taiwan; (I.V.B.M.); (H.N.A.); (S.-H.T.)
| | - Hana Nur Aini
- R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung-Li 32023, Taiwan; (I.V.B.M.); (H.N.A.); (S.-H.T.)
| | - Mary Madelaine G. Lagman
- School of Chemical, Biological, and Materials Engineering and Science, Mapúa University, 658 Muralla St., Intramuros, Manila 1002, Philippines; (M.M.G.L.); (R.R.A.)
| | - Shuo-Hsi Tang
- R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung-Li 32023, Taiwan; (I.V.B.M.); (H.N.A.); (S.-H.T.)
| | - Ruth R. Aquino
- School of Chemical, Biological, and Materials Engineering and Science, Mapúa University, 658 Muralla St., Intramuros, Manila 1002, Philippines; (M.M.G.L.); (R.R.A.)
| | - Yung Chang
- R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung-Li 32023, Taiwan; (I.V.B.M.); (H.N.A.); (S.-H.T.)
| | - Antoine Venault
- R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan Christian University, Chung-Li 32023, Taiwan; (I.V.B.M.); (H.N.A.); (S.-H.T.)
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17
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Transport and Separation of the Silver Ion with n-decanol Liquid Membranes Based on 10-undecylenic Acid, 10-undecen-1-ol and Magnetic Nanoparticles. MEMBRANES 2021; 11:membranes11120936. [PMID: 34940437 PMCID: PMC8707525 DOI: 10.3390/membranes11120936] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/17/2022]
Abstract
This paper presents a transport and recovery of silver ions through bulk liquid membranes based on n-decanol using as carriers 10-undecylenic acid and 10-undecylenyl alcohol. The transport of silver ions across membranes has been studied in the presence of two types of magnetic oxide nanoparticles obtained by the electrochemical method with iron electrodes in the electrolyte with and without silver ions, which act as promoters of turbulence in the membrane. Separation of silver ions by bulk liquid membranes using 10-undecylenic acid and 10-undecylenyl alcohol as carriers were performed by comparison with lead ions. The configuration of the separation module has been specially designed for the chosen separation process. Convective-generating magnetic nanoparticles were characterized in terms of the morphological and structural points of view: scanning electron microscopy (SEM), high-resolution SEM (HR-SEM), energy dispersive spectroscopy analysis (EDAX), Fourier Transform InfraRed (FTIR) spectroscopy, thermal gravimetric analysis (TGA), differential scanning calorimetry and magnetization. The process performance (flux and selectivity) was tested were tested for silver ion transport and separation through n-decanol liquid membranes with selected carriers. Under the conditions of the optimized experimental results (pH = 7 of the source phase, pH = 1 of the receiving phase, flow rate of 30 mL/min for the source phase and 9 mL/min for the receiving phase, 150 rot/min agitation of magnetic nanoparticles) separation efficiencies of silver ions of over 90% were obtained for the transport of undecenoic acid and about 80% for undecylenyl alcohol.
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Razmgar K, Nasiraee M. Polyvinyl alcohol
‐based membranes for filtration of aqueous solutions: A comprehensive review. POLYM ENG SCI 2021. [DOI: 10.1002/pen.25846] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Affiliation(s)
- Kourosh Razmgar
- College of Science, Health, Engineering and Education Murdoch University Perth Western Australia Australia
| | - Mohammad Nasiraee
- Chemical Engineering Department, Faculty of Engineering Ferdowsi University of Mashhad Mashhad Iran
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Osmium Nanoparticles-Polypropylene Hollow Fiber Membranes Applied in Redox Processes. NANOMATERIALS 2021; 11:nano11102526. [PMID: 34684968 PMCID: PMC8537536 DOI: 10.3390/nano11102526] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 09/21/2021] [Accepted: 09/23/2021] [Indexed: 12/17/2022]
Abstract
Composite membranes play a very important role in the separation, concentration, and purification processes, but especially in membrane reactors and membrane bioreactors. The development of composite membranes has gained momentum especially through the involvement of various nanoparticles, polymeric, oxide, or metal, that have contributed to increasing their reactivity and selectivity. This paper presents the preparation and characterization of an active metal nanoparticle-support polymer type composite membrane, based on osmium nanoparticles obtained in situ on a polypropylene hollow fiber membrane. Osmium nanoparticles are generated from a solution of osmium tetroxide in tert-butyl alcohol by reduction with molecular hydrogen in a contactor with a polypropylene membrane. The composite osmium-polypropylene hollow fiber obtained membranes (Os-PPM) were characterized from the morphological and structural points of view: scanning electron microscopy (SEM), high resolution SEM (HR-SEM), energy dispersive spectroscopy analysis (EDAX), X-ray diffraction analysis (XRD), Fourier transform Infrared (FTIR) spectroscopy, thermal gravimetric analysis, and differential scanning calorimetry (TGA, DSC). The process performance was tested in a redox process of p-nitrophenol and 10-undecylenic (10-undecenoic) acid, as a target substance of biological or biomedical interest, in solutions of lower aliphatic alcohols in a membrane contactor with a prepared composite membrane. The characteristics of osmium nanoparticles-polypropylene hollow fiber membranes open the way to biological and biotechnological applications. These membranes do not contaminate the working environment, operate at relatively low temperatures, provide a large contact area between reactants, allow successive oxidation and reduction operations in the same module, and help to recover the reaction mass by ultrafiltration. The results obtained show that the osmium-polypropylene composite membrane allows the reduction of p-nitrophenol or the oxidation of 10-undecylenic acid, the conversion depending on the concentration in the lower aliphatic alcohol, the nature of the lower aliphatic alcohol, and the oxidant or reducing flow through the membrane contactor.
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Reactional Processes on Osmium-Polymeric Membranes for 5-Nitrobenzimidazole Reduction. MEMBRANES 2021; 11:membranes11080633. [PMID: 34436396 PMCID: PMC8400646 DOI: 10.3390/membranes11080633] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Accepted: 08/13/2021] [Indexed: 12/28/2022]
Abstract
Membranes are associated with the efficient processes of separation, concentration and purification, but a very important aspect of them is the realization of a reaction process simultaneously with the separation process. From a practical point of view, chemical reactions have been introduced in most membrane systems: with on-liquid membranes, with inorganic membranes or with polymeric and/or composite membranes. This paper presents the obtaining of polymeric membranes containing metallic osmium obtained in situ. Cellulose acetate (CA), polysulfone (PSf) and polypropylene hollow fiber membranes (PPM) were used as support polymer membranes. The metallic osmium is obtained directly onto the considered membranes using a solution of osmium tetroxide (OsO4), dissolved in tert–butyl alcohol (t–Bu–OH) by reduction with molecular hydrogen. The composite osmium–polymer (Os–P)-obtained membranes were characterized in terms of the morphological and structural points of view: scanning electron microscopy (SEM), high-resolution SEM (HR–SEM), energy-dispersive spectroscopy analysis (EDAX), Fourier Transform Infra-Red (FTIR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The process performance was tested for reduction of 5–nitrobenzimidazole to 5–aminobenzimidazole with molecular hydrogen. The paper presents the main aspects of the possible mechanism of transformation of 5–nitrobenzimidazole to 5–aminobenzimidazole with hydrogen gas in the reaction system with osmium–polymer membrane (Os–P).
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