scholarly journals Iono-molecular Separation with Composite Membranes IV. Mono-nitrophenol s pervaporation through polysulfone composite membranes

2017 ◽  
Vol 54 (2) ◽  
pp. 353-358
Author(s):  
Hussam Nadum Abdalraheem Al Ani ◽  
Anca Maria Cimbru ◽  
Ion Spiridon Din ◽  
Szidonia Katalin Tanczos ◽  
Ion Marius Nafliu ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Composite Membrane ◽  
Composite Membranes ◽  
Feed Solution ◽  
Laboratory Installation ◽  
Membrane Performance ◽  
Advanced Composite ◽  
Molecular Separation ◽  
Pani Composite ◽  
Better Than

In this paper, were study the pervaporation of mono-nitrophenols in a laboratory installation of the Membrane, Materials, and Membrane Processes Group of the Polytechnic University of Bucharest, from aqueous synthetic solutions, to composite membranes with polysulfone matrix (PSf) and nanometric inclusions: Polyaniline (PANI), carbon nanotubes (CNT), magnetic nanoparticles (MNP) and sulfonated polyetheretherketone (PEEK-S). Tests carried out over 144 h at a pressure of 100 mm Hg or 5 L / min air flow at 25oC and pH 7 of the feed solution show that vacuum pervaporation is better than vacuum. The more advanced composite membranes are those with sulfonated polyether-ether cellulose (PSf-PEEK-S) and polyaniline (PSf-PANI) ionizers. The results of airborne pervaporation show that composite membranes (PSf-PEEK-S and PSf-PANI) present a marked difference in flux for the mono-mono-nitrophenol isomers, which could also be found in a technically exploitable selectivity. Thus, in the case of the PSf-PEEK-S composite membrane, the mono-nitro-phenol streams decrease in the order: m-C6H5NO3] o-C6H5NO3] p-C6H5NO3, while for the PSf-PANI composite membrane the order is o-C6H5NO3] m-C6H5NO3] p-C6H5NO3. At the same time, it is noted that the PSf-PEEK-S composite membrane performance is superior during operation, but shows the opposite of the more pronounced drop.

scholarly journals Pressure effect during the formation of a selective layer on the structure and performance of dynamic composite membranes for pervaporation

2021 ◽  
Vol 65 (4) ◽  
pp. 431-438
Author(s):  
K. S. Burts ◽  
T. V. Plisko ◽  
A. V. Bildyukevich ◽  
G. Li ◽  
J. Kujawa ◽  
...  
Keyword(s):  
Contact Angle ◽  
Polymer Matrix ◽  
Composite Membrane ◽  
Substrate Surface ◽  
Composite Membranes ◽  
Feed Solution ◽  
Porous Membrane ◽  
Transmembrane Pressure ◽  
Dynamic Mode ◽  
Selective Layer

Composite membranes for pervaporation were prepared by forming a selective layer based on cross-linked polyvinyl alcohol (PVA) on the porous membrane-substrate surface in the dynamic mode (via PVA solution ultrafiltration). It was found that the pressure growth results in increasing the thickness of the composite membrane selective layer. Composite membrane contact angle, flux, water content in permeate in ethanol/water (mass ratio 90/10) pervaporation were revealed to have maximum values at 3–4 atm depending on the PVA concentration in the feed solution. It was shown that the revealed dependence of the contact angle, selectivity, and permeability on the pressure of the selective layer formation is due to the compaction of the polymer matrix-substrate under the action of the transmembrane pressure and its relaxation after pressure release. When using elevated pressures (more than 3–4 atm), the relaxation of the polymer matrix causes the microdefect to form as a result of deformation of the selective layer.

scholarly journals Effect of MWCNT Filler on Properties and Flux of Chitosan/ PEG based Nanocomposites Membranes

2018 ◽  
Vol 156 ◽  
pp. 04001
Author(s):  
Fitri Khoerunnisa ◽  
Hendrawan ◽  
Dwi Rizki Primastari ◽  
Riska Agiawati
Keyword(s):  
Contact Angle ◽  
Composite Membrane ◽  
Effective Interaction ◽  
Volume Ratio ◽  
Composite Membranes ◽  
Phase Method ◽  
Multiwalled Carbon ◽  
Sem Images ◽  
Membrane Performance ◽  
Poly Ethylene

Biopolymer are expected to be environmentally compatible and to have great potential application as membranes material. The chitosan-poly (ethylene glycol)/PEG based composite membranes was successfully synthesized via inversed phase method. The effect of multiwalled carbon nanotubes (MWCNT) as nanofiller on properties and performances of composite membranes were intensively evaluated. The membrane was prepared by mixing of chitosan and PEG solutions at the same composition ratio while MWCNT amount in the mixture was varied. The synthesized membrane was characterized by means of FTIR spectroscopy, scanning electron microscopy (SEM), contact angle, and tensile strength measurement. The performance of composite membrane on filtration was evaluated in term of flux (permeability) and rejection (rejection) tests. The results showed that the optimum volume ratio of composite membrane solution was found at 30:10:7.5 for chitosan/ PEG/ MWCNT, respectively, as indicated by the largest flux. Insertion of MWCNT nanofiller notably enhanced hydrophilicity, porosity, and mechanical properties of composites membranes that are confirmed by contact angle, SEM images and elongation forces value, respectively. The MWCNT nanofiller remarkably increased both of flux and rejection of composite membranes up to 60 Lm2h-1 and 96%, respectively. The remarkable enhancement of composite membrane performance is attributed to the effective interaction of MWCNT with polymeric matrix.

scholarly journals Cellulose and Chitosan Composite Membranes for Protein and Salt Filtration

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
P. Rakbamrung ◽  
P. Wanichapichart ◽  
Y. Tirawanichakul
Keyword(s):  
Composite Membrane ◽  
Chitosan Solution ◽  
Composite Membranes ◽  
Feed Solution ◽  
Hydraulic Permeability ◽  
Cellulose Membrane ◽  
Permeate Flux ◽  
Molecular Weights ◽  
Chitosan Composite ◽  
Supporting Membrane

Cellulose membrane (SE) was prepared by culturing Acetobacter xylinum in a media with sucrose as a carbon source and was used as a supporting membrane in this study. Pore size of the supporting membrane was studied by means of molecular weight cut off (MWCO) and SEM micrographs. For making cellulose/chitosan composite membrane SE/CH, chitosan solution was used as a coating polymer and applied by a casting method.This resulted in a smaller hydraulic permeability coefficient (Lp) from 6.7 × 10–11 m3 N–1 s–1 in membrane SE to 1.94 × 10–12 m3 N–1 s–1 in the composite membrane SE/CH. Using PEG of several molecular weights as feed solution, the MWCO of the SE membrane was 200 kDa while that of the SE/CH membrane was 6 kDa. The former rejected 1 g L–1 BSA by 80%. With pH between 3 and 8, the composite membrane SE/CH rejected NaCl and NaHCO3 by 50%, independent of the pH level. However, when using a divalent salt solution of MgSO4 the rejection was increased up to 85%, with an optimum at pH 6–7 and a permeate flux of 5.0 L m–2h–1 at pressures of 0.5 MPa.

scholarly journals Iono-molecular Separation with Composite Membranes. VII. Nitrophenols pertraction on capilary polypropylene S-EPDM composite membranes

2018 ◽  
Vol 55 (4) ◽  
pp. 511-516
Author(s):  
Ion Marius Nafliu ◽  
Hussam Nadum Abdalraheem Al Ani ◽  
Alexandra Raluca Grosu (Miron) ◽  
Szidonia Katalin Tanczos ◽  
Ioana Maior ◽  
...  
Keyword(s):  
Chemical Reaction ◽  
Oxidative Degradation ◽  
Coupling Reaction ◽  
Composite Membranes ◽  
Complexation Reaction ◽  
Laboratory Installation ◽  
Ethylene Propylene ◽  
Molecular Separation ◽  
Pka Value ◽  
Ethylene Propylene Diene Terpolymer

In the present paper the authors study the pertraction of the nitrophenols through the immobilization using chemical reaction in receiving phase, using a laboratory installation conceived by the Group of Membranes, Materials and Membrane Processes within University Politehnica of Bucharest. This installation was developed using liquid synthetically solutions, through composite membranes having a matrix of capillary polypropylene and inclusions of ethylene propylene diene terpolymer sulfonic acid (S-EPDM) or sulfonated ethylene-propylene-diene terpolymer (S-EPDM). The results were follow: The permeation through the compartments of the system with composite S-EPDM membranes is limited, in the aqueous phases, by the solubility of the compound about to be separated, namely the membrane itself, and subsequently by its diffusion from the feed compartment to the collection compartment. The chemical reaction of immobilization, in the receiving phase, can be achieved in several variants (neutralization, esterification, complexation, oxidation, coupling, oxidative degradation); The biggest flows are obtained in compensation of the o-nitrophenol with ferric ions and then, in acetylation of the o-nitrophenol with acetic anhydride. However, we can emphasize that the derivatization of the o-nitrophenol through complexation and acetylation reactions requires its use as such in later processes, unlike the neutralization, for which the nitrophenolate ion easily frees the nitrophenol for future applications;For the neutralization reaction, the removing coefficient grows with decreasing of pKa value of the nitrophenols. For complexation reaction, the most favorable results were obtained for o-nitrophenol - over 66%;The coupling reaction of the o-nitrophenol, in the receiving phase, with the diazonium chloride of the p-nitroaniline and hydrogen peroxide 3% in sulfuric acid 20%, respectively, concludes with the exhaustion of the source phase, after 24 hours of operation.

Iono-molecular Separation with Composite Membranes III. Nitrophenols separation on polysulphone and composite nanoparticles ultrafiltration

2017 ◽  
Vol 68 (3) ◽  
pp. 427-434
Author(s):  
Hussam Nadum Abdalraheem Al Ani ◽  
Anca Maria Cimbru ◽  
Szidonia Katalin Tanczos ◽  
Ion Spiridon Din ◽  
Adriana Cuciureanu ◽  
...  
Keyword(s):  
Solid Phase ◽  
Polymeric Nanoparticles ◽  
Composite Membranes ◽  
Feed Solution ◽  
Composite Nanoparticles ◽  
Operational Parameters ◽  
Working Pressure ◽  
Polysulfone Membrane ◽  
Molecular Separation ◽  
Turbulent Flow Regime

Building on the excellent results of extraction on a solid phase (polymer) this work combine adsorption nitrophenols (a, m, p-nitrophenols) on polymeric nanoparticles (NP-PSf) and composite (NP-PSf-PANI) with colloidal ultrafiltration. Colloidal ultrafiltration solutions of nitrophenols is done in an ultrafiltration plant, CELF System, with a capacity of 500 mL at 25oC, variable working pressure (1-10 atmospheres), turbulent flow regime (2-4 m/s) and usable filter polysulfone-membrane composites 10% in dimethylformamide coagulated with methanol polyaniline (PANI-PSf) 15 cm2. Operational parameters of the process: concentration nitrophenols, nanoparticle concentration, pH of the feed solution were studied, trying to correlate the results of the colloidal ultrafiltration with the nature of the nanoparticles. Permeate flow is optimal at a pressure of 5 atm and nitrophenols retention depends on their nature. Good results have been obtained at pH = 3.1 for polysulfone nanoparticles (NP) and excellent retention at pH 1.3 or pH]7, for composite nanoparticles (NP-PSf-PANI). Rejection o-nitrophenols is superior to the others two nitrophenols in all experiments.

Preparation and properties of poly(aryl ether ketone)-based phthalonitrile conductive composite film

2017 ◽  
Vol 31 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Jingjing Ma ◽  
Tao Liu ◽  
Weiting Wang ◽  
Yanhua Yang
Keyword(s):  
Carbon Nanotubes ◽  
Composite Membrane ◽  
Composite Membranes ◽  
Aryl Ether ◽  
Conductive Composite ◽  
Membrane Materials ◽  
Blending Method ◽  
Aryl Ether Ketone ◽  
Ether Ketone ◽  
Conductive Composite Membrane

A series of poly(aryl ether ketone) polymers containing phthalonitrile with relatively high molecular weights showed good film formation and toughness to be the good candidate for matrix of functional composites. To develop the application of bisphthalonitrile resins in the conductive composite membrane materials field, the phthalonitrile resin/multiwalled carbon nanotubes conductive composite membranes were prepared by the solution blending method. The conductive composite membranes have low percolation threshold (0.25 vol.%) and excellent conductive properties. With 0.79% weight fraction of carbon nanotubes, the cross-linking membrane shows a great enhancement in mechanical properties. They have the potential to be alternative candidates in the field of high-temperature, conductive composite membrane materials.

Iono-molecular Separation with Composite Membranes II. Preparation and characterization of polysulphone and composite nanoparticles

2017 ◽  
Vol 68 (2) ◽  
pp. 203-209
Author(s):  
Hussam Nadum Abdalraheem Al Ani ◽  
Anca Maria Cimbru ◽  
Corneliu Trisca-Rusu ◽  
Szidonia Katalin Tanczos ◽  
Adriana Cuciureanu ◽  
...  
Keyword(s):  
Chemical Species ◽  
Composite Membranes ◽  
Ammonium Persulfate ◽  
Operating Pressure ◽  
Polysulfone Membrane ◽  
Polymeric Nanoparticle ◽  
Molecular Separation ◽  
Copper Complexation ◽  
Molecular Separations ◽  
Methyl Pyrrolidone

This paper illustrates the possibility of producing iono-molecular separations using ionic colloidal ultrafiltration membrane of polysulfone synthetic solutions of cupric ions and nitro phenols through ultrafiltration assisted by polymeric nanoparticle composites based on polysulfone. In the present work, in order to reduce the operating pressure and increase the flow of water we are using the process of ultrafiltration through a polysulfone membrane in N-methylpyrrolidone 10% prepared by coagulation in isopropanol. The nanoparticles needed in colloidal ultrafiltration had been obtained through the immersion technique of precipitation of a solution of 5% PSf in N-methyl pyrrolidone containing 3% aniline in lower alcohols: methanol, ethanol, and isopropanol, followed by the oxidation of the remaining aniline in a solution of 10% hydrochloric acid and ammonium persulfate. The Nanoparticles of polysulfone (NP-PSf) and The three obtained variants of nanoparticles composites (NP-PSf-PANI) were morphologically (SEM) and (AFM), structurally and compositionally (FTIR) characterized and the results show that nanoparticles polysulfone have a much lower range than the composites. The Possibility of copper complexation by both nitrophenols, and by nanoparticle surface probably lead to the formation of more stable aggregates in the supply, which can sufficiently justify the increased retention. The Retentions of the chemical species in question use in all the tests made the same series:R NP-PSf-PANI-M] R NP-PSf-PANI-E] R NP-PSf-PANI-P] R NP-PSf

Iono-molecular Separation with Composite Membranes VI. Nitro-phenol separation through sulfonated polyether ether ketone on capillary polypropylene membranes

2018 ◽  
Vol 69 (7) ◽  
pp. 1603-1607
Author(s):  
Ion Spiridon Din ◽  
Anca Maria Cimbru ◽  
Abbas Abdul Kadhim Klaif Rikabi ◽  
Szidonia Katalin Tanczos ◽  
Simona Ticu (Cotorcea) ◽  
...  
Keyword(s):  
Flow Rate ◽  
Water Solubility ◽  
Composite Membranes ◽  
Membrane System ◽  
Polyether Ether Ketone ◽  
Molecular Separation ◽  
Capillary Membrane ◽  
Sulfonated Polyether Ether Ketone ◽  
Source Phase ◽  
Receptor Phase

The importance of removing and / or separating nitro phenols from aqueous solutions through membranes is substantiated by the multitude of recent research in the field, which broadly justifies both the economic and ecological reasons of such an approach. The present paper outlines the results of the transfer of nitro phenols through a membrane system made up of PPET impregnated polypropylene capillaries (PP) impregnated with sulfonate polyetheretherketone (SPEEK). The experiments were carried out in a PP-SPEEK capillary membrane module, with a useful size of 1 m2. Determinations made by using a 4 L / min flow rate source at a 5 mg / l nitrophenol concentration and pH 5 or pH 7, and the pH 12 receiving phase and a flow rate of 0.3 L / min, revealed that o- and p-nitrophenol were transferred much faster than m-nitrophenol (the flux is nearly double); the source phase of the system is concentrated in m-nitrophenol, and the receptor phase in o- and p-nitro phenols; the transfer data correlates with the higher water solubility of m-nitrophenol; mono nitro phenols transfer much faster than di nitrophenol, but both the mono and di nitrophenol streams decrease over time; after 4-5 hours of work, the mono nitrophenol concentration triples in the receiving phase, while the 2,4-dinitrophenol concentration doubles in the source phase.

Synthesis and characterization of flame-retardant-wrapped carbon nanotubes and its flame retardancy in epoxy nanocomposites

2021 ◽  
pp. 096739112110245
Author(s):  
Jiangbo Wang
Keyword(s):  
Carbon Nanotubes ◽  
Heat Release ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Total Heat Release ◽  
Pristine Cnts ◽  
Peak Heat Release Rate ◽  
Ep Matrix ◽  
Better Than

A novel phosphorus-silicon containing flame-retardant DOPO-V-PA was used to wrap carbon nanotubes (CNTs). The results of FTIR, XPS, TEM and TGA measurements exhibited that DOPO-V-PA has been successfully grafted onto the surfaces of CNTs, and the CNTs-DOPO-V-PA was obtained. The CNTs-DOPO-V-PA was subsequently incorporated into epoxy resin (EP) for improving the flame retardancy and dispersion. Compared with pure EP, the addition of 2 wt% CNTs-DOPO-V-PA into the EP matrix could achieve better flame retardancy of EP nanocomposites, such as a 30.5% reduction in peak heat release rate (PHRR) and 8.1% reduction in total heat release (THR). Furthermore, DMTA results clearly indicated that the dispersion for CNTs-DOPO-V-PA in EP matrix was better than pristine CNTs.

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