Search for: phase-separation
Total 72 records
Property Investigation of Poly (Ethylene Co-vinyl Acetate)/Poly (l-Lactic Acid)/Organo Clay Nanocomposites, Article Journal of Polymers and the Environment ; Volume 27, Issue 12 , 2019 , Pages 2886-2894 ; 15662543 (ISSN) ; Ramazani SaadatAbadi, A ; Sharif University of Technology
Springer New York LLC 2019
In this study, EVAc/PLA/organo clay nanocomposites were prepared via solution mixing method. The SEM images were used to investigate the morphology of nanocomposites revealing no phase separation or agglomeration of disperse phase in EVAc/PLA blends and nanocomposites. SAXS spectra confirmed the intercalated morphology of nanocomposites. Soil burial test were carried out and the rate of degradation of the samples were measured indirectly. Oxygen gas permeability of EVAc was slightly decreased by adding PLA to the matrix, when small loads of clay caused dramatic improvement in barrier properties. Melt rheological frequency sweep test illustrated the compatibility of EVAc with low contents of...
Pectic acid–graphene oxide nanocomposite as an adsorbent in vortex-assisted dispersive solid-phase extraction for preconcentration of copper ion followed by flame atomic absorption spectrometry, Article Polymer Bulletin ; Volume 77, Issue 6 , 2020 , Pages 2821-2836 ; Shakerian, M ; Majeed, H. J ; Eftekhari, M ; Rezazadeh, N ; Sharif University of Technology
An efficient, green, novel and rapid vortex-assisted dispersive solid-phase extraction (VADSPE) technique was used for the preconcentration and determination of trace levels of Cu2+ followed by flame atomic absorption spectrometry. Graphene oxide (GO) was synthesized from graphite and then modified by pectic acid (poly-d-galacturonic acid, PA) to synthesize the pectic acid–graphene oxide (PA-GO) nanocomposite. The Fourier transform infrared spectrophotometry, field emission scanning electron microcopy, energy-dispersive X-ray spectroscopy and X-ray diffraction analysis were used to characterize the synthesized GO-PA nanocomposite. By using VADSPE technique, PA-GO was used as an adsorbent for...
Effect of reactive diluent on gas separation behavior of photocurable acrylated polyurethane composite membranes, Article Journal of Applied Polymer Science ; Volume 137, Issue 3 , 15 January , 2020 ; Shojaei, A ; Mousavi, S. A ; Ahmadi, S. A ; Sharif University of Technology
John Wiley and Sons Inc 2020
In this study, the effects of the type and content of reactive diluents on the permeation/separation of carbon dioxide/nitrogen (CO2/N2) through acrylate-terminated polyurethane (APU)-acrylate/acrylic diluent (APUA) composite membranes was investigated. A series of APUs based on poly(ethylene glycol) (PEG)-1000 g mol−1, toluene diisocyanate, and 2-hydroxyethyl methacrylate was synthesized and then diluted with several reactive diluents. The results obtained from differential scanning calorimetry (DSC) and Fourier transform infrared analyses showed that the microphase interference of hard and soft segments increased with increasing reactive diluent content. Furthermore, with increasing alkene...
In situ synthesized TiO2-polyurethane nanocomposite for bypass graft application: In vitro endothelialization and degradation, Article Materials Science and Engineering C ; Volume 114 , May , 2020 ; Bagheri, R ; Pourjavadi, A ; Ghanbari, H ; Sharif University of Technology
Elsevier Ltd 2020
The in vitro endothelial response of human umbilical vein endothelial cells was investigated on a poly (caprolactone)-based polyurethane surface vs an in situ TiO2-polyurethane nanocomposite surface, which has been produced as scaffolds for artificial vascular graft. The in situ synthesis of TiO2 nanoparticles in polyurethane provided surface properties that facilitated cellular adhesion, cell sensing, cell probing and especially cell migration. Cells on the nanocomposite surface have elongated morphology and were able to produce more extracellular matrix. All of these advantages led to an increase in the rate of endothelialization of the nanocomposite scaffold surface vs pure polyurethane....
Novel nanocomposite polyethersulfone- antimony tin oxide membrane with enhanced thermal, electrical and antifouling properties, Article Polymer ; Volume 163 , 2019 , Pages 48-56 ; 00323861 (ISSN) ; Hosseini, S. A ; Ma, G ; McGregor, M ; Sadrzadeh, M ; Sharif University of Technology
Elsevier Ltd 2019
Application of organic−inorganic nanocomposite membranes for water treatment is exceptionally growing owing to their tunable functionalities in addition to their enhanced permeation and antifouling propensity. In the present work, novel nanocomposite polyethersulfone (PES) membrane was synthesized using antimony-doped tin oxide (ATO) nanoparticles (NPs) via phase separation technique. It was found that the modified PES-ATO nanocomposite membranes exhibited significantly higher fouling resistance and larger permeate flux recovery ratio when tested with oil sands produced water than unmodified PES membranes. Furthermore, the PES-ATO membranes provided 40% more organic matter removal compared...
PVDF/PU blend membrane separator for lithium-ion batteries via non-solvent-induced phase separation (NIPS), Article Journal of Solid State Electrochemistry ; Volume 25, Issue 8-9 , 2021 , Pages 2385-2394 ; 14328488 (ISSN) ; Fathollahi Zonouz, A ; Soltanieh, M ; Mousavi, S. A ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH 2021
Membrane separator based on the polyvinylidene fluoride (PVDF) is prepared via the non-solvent-induced phase separation (NIPS) method with water and ethanol as non-solvent and a mixture of dimethylformamide (DMF) and acetone as solvent. The effect of various acetone/DMF ratios and non-solvent material on the physical and electrochemical properties of the separator is studied by FE-SEM, tensile strength, electrochemical AC-impedance spectroscopy (EIS), thermal stability, and linear sweep voltammetry (LSV). The charge-discharge studies are carried out by fabricating a lithium foil/polymer electrolyte membrane/LiFePO4 cell. The results show that with the change of solvent and non-solvent, the...
Molecular engineering and morphology of polyurethane elastomers containing various molecular weight of macrodiol, Article Materials Science and Engineering B: Solid-State Materials for Advanced Technology ; Volume 264 , 2021 ; 09215107 (ISSN) ; Zuber, M ; Barikani, M ; Salman, M ; Sharif University of Technology
Elsevier Ltd 2021
A series of polyurethane elastomers (PUEs) based on 4,4′-cyclohexamethylene diisocyanate (H12MDI)/1,2-ethanediol as hard segment with the soft segments having different molecular weights of polycaprolactone diols, were effectively polymerized by two step technique. The structural characterization was performed by FT-IR spectroscopy. The X-ray diffraction (XRD) technique was used to study the crystallinity and hydrophilicity of the prepared polymer films. It was found that crystallinity and hydrophilicity increased with increasing the chain length of soft segments. The effect of molecular weight of polyols on the contact angle, water absorption (%) and swelling behavior of the synthesized...
Simultaneous separation of H2S and CO2 from CH4 by a high silica CHA-type zeolite membrane, Article Journal of Membrane Science ; Vol. 470, issue , 2014 , pp. 159-165 ; ISSN: 03767388 ; Soltanieh, M ; Sharif University of Technology
A high silica CHA-type membrane was synthesized by the in-situ crystallization method on a disk like α-alumina porous support to separate both acid (H2S, CO2) gases from methane. The membrane showed a permeance of 3.39×10-8mol/m2sPa for pure CO2with CO2/CH4 ideal selectivity of 21.6 at 303K and 100kPa pressure difference across the membrane. The membrane was also tested with N2 and O2 pure gases indicating a small O2/N2 selectivity of 1.2-1.4, which shows that this type of membrane is not suitable for O2/N2 separation. The membrane performance was also analyzed by binary (CO2-CH4) and ternary (H2S-CO2-CH4) gas mixtures, with compositions near the real sour natural gas (CO2: 2.13mol%, H2S:...
Electrospun titania sol-gel-based ceramic composite nanofibers for online micro- solid-phase extraction with high-performance liquid chromatography, Article Journal of Separation Science ; Vol. 37, issue. 15 , August , 2014 , pp. 1982-1988 ; ISSN: 16159306 ; Piri-Moghadam, H ; Rastegar, S ; Taheri, N ; Sharif University of Technology
Titanium(IV) tetraisopropoxide was employed as a metal oxide sol-gel precursor to prepare ceramic composite nanofibers by the electrospinning system. To facilitate this process and obtain the desired nanofibers with higher aspect ratios and surface area, poly(vinylpyrrolidone) was added to the sol of titania. Four ceramic nanofibers sheets based on titania were prepared while each sheet contained different transition metals such as Fe-Mn, Fe-Ni, Fe-Co, and Fe-Mn-Co-Ni. The scanning electron microscope images showed good homogeneity for all the prepared ceramic composites with a diameter range of 100-250 nm. The sorption efficiency was investigated by a micro-solid-phase extraction setup in...
High-throughput micro-solid phase extraction on 96-well plate using dodecyl methacrylate-ethylen glycol dimethacrylate monolithic copolymer, Article Analytica Chimica Acta ; Volume 792 , August , 2013 , Pages 59-65 ; 00032670 (ISSN) ; Es'haghi, A ; Es-haghi, A ; Mohammadkhani, E ; Sharif University of Technology
A novel high-throughput device based on 96-micro-solid phase extraction (96-μ-SPE) system was constructed for multiresidue determination of nine pesticides in aquatic samples. The extraction procedure was performed on a commercially available 96-well plate system. The extraction module consisted of 96 pieces of 1cm×3cm of cylindrically shaped stainless steel meshes. The prepared meshes were fixed in a home-made polytetrafluoroethylene-based constructed ninety-six holes block for possible simultaneous immersion of meshes into the center of individual wells. Dodecyl methacrylate and ethylene glycol dimethacrylate was copolymerized as a monolithic polymer and placed in the cylindrically shaped...
Extraordinary swelling behavior of poly (AMPS) organogelin solvent/DMSO binary mixed media, Article Journal of Applied Polymer Science ; Volume 117, Issue 2 , July , 2010 , Pages 1127-1136 ; 00218995 (ISSN) ; Kabiri, K ; Kheirabadi, M ; Sharif University of Technology
The present article deals with super-swelling behavior of crosslinked homopolymer of 2-acrylamido-2-methylpropane sulfonic acid, poly(AMPS), in binary mixtures of dimethyl sulfoxide (DMSO) and various polar solvents including water, mono-, and polyhydric alcohols, and amide solvents such as N-methyl pyrrolidone. Extraordinary phase transition sequences including a new unusual swelling phenomenon, referred to as "overentrant" swelling, was observed for this polymeric organogel in the solvent/DMSO mixtures. The swelling behaviors were preliminarily explained based on the major interactions involved in the solvation process and dielectric constant of the swelling media. It was established that...
Investigation of the interphase effects on the mechanical behavior of carbon nanotube polymer composites by multiscale modeling, Article Journal of Applied Polymer Science ; Volume 117, Issue 1 , March , 2010 , Pages 361-367 ; 00218995 (ISSN) ; Naghdabadi, R ; Sharif University of Technology
In this article, a multiscale modeling procedure is implemented to study the effect of interphase on the Young's modulus of CNT/polymer composites. For this purpose, a three-phase RVE is introduced which consists of three components, i.e., a carbon nanotube, an interphase layer, and an outer polymer matrix. The nanotube is modeled at the atomistic scale using molecular structural mechanics. Moreover, three-dimensional elements are employed to model the interphase layer and polymer matrix. The nanotube and polymer matrix are assumed to be bonded by van der Waals interactions based on the Lennard-Jones potential at the interface. Using this Molecular Structural Mechanics/Finite Element...
Multi-response optimization followed by multivariate calibration for simultaneous determination of carcinogenic polycyclic aromatic hydrocarbons in environmental samples using gold nanoparticles, Article RSC Advances ; Volume 6, Issue 106 , 2016 , Pages 104254-104264 ; 20462069 (ISSN) ; Parastar, H ; Hormozi Nezhad, M. R ; Sharif University of Technology
Royal Society of Chemistry
In this study, a multivariate-based strategy was developed for simultaneous determination of thirteen carcinogenic polycyclic aromatic hydrocarbons (PAHs) in water samples using gold nanoparticles (AuNPs) as solid-phase extraction (SPE) sorbent combined with gas chromatography (GC). The extraction technique is based on the strong affinity between citrate-capped AuNPs and PAHs. Furthermore, characterization of AuNPs was performed by UV-vis spectroscopy and transmission electron microscopy (TEM) techniques. A rotatable central composite design (CCD) combined with multiple linear regression (MLR) was used for designing the extraction procedure and developing models using the GC peak areas of 13...
Dispersive micro-solid phase extraction using magnetic nanoparticle modified multi-walled carbon nanotubes coupled with surfactant-enhanced spectrofluorimetry for sensitive determination of lomefloxacin and ofloxacin from biological samples, Article Materials Science and Engineering C ; Volume 60 , 2016 , Pages 30-36 ; 09284931 (ISSN) ; Pourghazi, K ; Hajjaran, S ; Sharif University of Technology
A dispersive micro-solid-phase extraction (D-μ-SPE) procedure coupled with surfactant-enhanced spectrofluorimetric detection was developed for determination of ofloxacin and lomefloxacin from biological and environmental samples. The D-μ-SPE procedure was performed using magnetic Fe3O4 nanoparticle grafted multi-walled carbon nanotube as an efficient adsorbent. The main factors affecting the signal enhancement (including surfactant concentration and pH) and extraction efficiency (including pH, extraction time, sample volume, amount of magnetic adsorbent, and desorption conditions) were investigated in detail. Under the optimized conditions, the calibration curves were linear (R2 0.9995) over...
Optimized composition of nanocomposite scaffolds formed from silk fibroin and nano-TiO2 for bone tissue engineering, Article Materials Science and Engineering C ; Volume 79 , 2017 , Pages 783-792 ; 09284931 (ISSN) ; Madaah Hosseini, H. R ; Samadikuchaksaraei, A ; Sharif University of Technology
Natural silk fibroin (SF) polymer has biomedical and mechanical properties as a biomaterial for bone tissue engineering scaffolds. Freeze-dried porous nanocomposite scaffolds were prepared from silk fibroin and titanium dioxide (TiO2) nanoparticles as a bioactive reinforcing agent by a phase separation method. In order to fabricate SF/TiO2 scaffolds, 5, 10, 15 and 20 wt% of the TiO2 were added to the SF. The phase structure, functional groups and morphology of the scaffolds were evaluated using X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy techniques, respectively. Porosity of the scaffolds was measured by Archimedes' Principle. In addition,...
Plant protein-based hydrophobic fine and ultrafine carrier particles in drug delivery systems, Article Critical Reviews in Biotechnology ; Volume 38, Issue 1 , 2018 , Pages 47-67 ; 07388551 (ISSN) ; Mirshekari, H ; Sahandi Zangabad, P ; Moosavi Basri, S. M ; Baniasadi, F ; Sharifi Aghdam, M ; Karimi, M ; Hamblin, M. R ; Sharif University of Technology
Taylor and Francis Ltd 2018
For thousands of years, plants and their products have been used as the mainstay of medicinal therapy. In recent years, besides attempts to isolate the active ingredients of medicinal plants, other new applications of plant products, such as their use to prepare drug delivery vehicles, have been discovered. Nanobiotechnology is a branch of pharmacology that can provide new approaches for drug delivery by the preparation of biocompatible carrier nanoparticles (NPs). In this article, we review recent studies with four important plant proteins that have been used as carriers for targeted delivery of drugs and genes. Zein is a water-insoluble protein from maize; Gliadin is a 70% alcohol-soluble...
Anaerobic treatment of synthetic medium-strength wastewater using a multistage biofilm reactor, Article Bioresource Technology ; Volume 100, Issue 5 , 2009 , Pages 1740-1745 ; 09608524 (ISSN) ; Borja, R ; Monemian, S. A ; Goodarzi, V ; Sharif University of Technology
A laboratory-scale multistage anaerobic biofilm reactor of three compartments with a working volume of 54-L was used for treating a synthetic medium-strength wastewater containing molasses as a carbon source at different influent conditions. The start-up period, stability and performance of this reactor were assessed at mesophilic temperature (35 °C). During the start-up period, pH fluctuations were observed because there was no microbial selection or zoning, but as the experiment progressed, results showed that phase separation had occurred inside the reactor. COD removal percentages of 91.6, 91.6, 90.0 and 88.3 were achieved at organic loading rates of 3.0, 4.5, 6.75 and 9.0 kg COD/m3 day,...
A novel magnetic poly(aniline-naphthylamine)-based nanocomposite for micro solid phase extraction of rhodamine B, Article Analytica Chimica Acta ; Volume 794 , 2013 , Pages 38-46 ; 00032670 (ISSN) ; Daliri, R ; Roostaie, A ; Sharif University of Technology
A novel Fe3O4-poly(aniline-naphthylamine)-based nanocomposite was synthesized by chemical oxidative polymerization process as a magnetic sorbent for micro solid phase extraction. The scanning electron microscopy images of the synthesized nanocomposite revealed that the copolymer posses a porous structure with diameters less than 50nm. The extraction efficiency of this sorbent was examined by isolation of rhodamine B, a mutagenic and carcinogenic dye, from aquatic media in dispersion mode. Among different synthesized polymers, Fe3O4/poly(aniline-naphthylamine) nanocomposite showed a prominent efficiency. Parameters including the desorption solvent, amount of sorbent, desorption time, sample...
Multivariate curve resolution-particle swarm optimization: A high-throughput approach to exploit pure information from multi-component hyphenated chromatographic signals, Article Analytica Chimica Acta ; Volume 772 , 2013 , Pages 16-25 ; 00032670 (ISSN) ; Ebrahimi Najafabadi, H ; Jalali Heravi, M ; Sharif University of Technology
Multivariate curve resolution-particle swarm optimization (MCR-PSO) algorithm is proposed to exploit pure chromatographic and spectroscopic information from multi-component hyphenated chromatographic signals. This new MCR method is based on rotation of mathematically unique PCA solutions into the chemically meaningful MCR solutions. To obtain a proper rotation matrix, an objective function based on non-fulfillment of constraints is defined and is optimized using particle swarm optimization (PSO) algorithm. Initial values of rotation matrix are calculated using local rank analysis and heuristic evolving latent projection (HELP) method. The ability of MCR-PSO in resolving the chromatographic...
Sol-gel-based silver nanoparticles-doped silica - Polydiphenylamine nanocomposite for micro-solid-phase extraction, Article Analytica Chimica Acta ; Volume 886 , July , 2015 , Pages 56-65 ; 00032670 (ISSN) ; Banihashemi, S ; Sharif University of Technology
A nanocomposite of silica-polydiphenylamine doped with silver nanoparticles (Ag-SiO
2-PDPA) was successfully synthesized by the sol-gel process. For its preparation, PDPA was mixed with butanethiol capped Ag nanoparticles (NPs) and added to the silica sol solution. The Ag NPs were stabilized as a result of their adsorption on the SiO 2 spheres. The surface characteristic of nanocomposite was investigated using scanning electron microscopy (SEM). In this work the Ag-SiO 2-PDPA nanocomposite was employed as an efficient sorbent for micro-solid-phase extraction (μ-SPE) of some selected pesticides. An amount of 15 mg of the prepared sorbent was used to extract and...