Search for: polyvinyl-alcohols
0.006 seconds
Total 42 records

    Fabrication and evaluation of chitosan/gelatin/PVA hydrogel incorporating honey for wound healing applications: An in vitro, in vivo study

    , Article International Journal of Pharmaceutics ; 2020 Shamloo, A ; Aghababaie, Z ; Afjoul, H ; Jami, M ; Bidgoli, M. R ; Vossoughi, M ; Ramazani, A ; Kamyabhesari, K ; Sharif University of Technology
    Elsevier B.V  2020
    In this study, physically cross-linked hydrogels were developed by freezing-thawing method while different concentrations of honey were included into the hydrogels for accelerated wound healing. The hydrogel was composed of chitosan, polyvinyl alcohol (PVA), and gelatin with the ratio of 2:1:1 (v/v), respectively. Further, the effect of honey concentrations on antibacterial properties, and cell behavior was investigated. In vivo studies, including wound healing mechanism using rat model and histological analysis of section tissue samples were performed. The results illustrated that the incorporation of honey in hydrogels increased the ultimate strain of hydrogels approximately two times,... 

    Enhancing sonocatalytic properties of TiO2 nanocatalysts by controlling the surface conditions: effect of particle size and PVA modification

    , Article Desalination and Water Treatment ; Volume 57, Issue 58 , 2016 , Pages 28378-28385 ; 19443994 (ISSN) Soleimani, F ; Madaah Hosseini, H. R ; Ordikhani, F ; Mokhtari Dizaji, M ; Sharif University of Technology
    Taylor and Francis Inc  2016
    The influence of particle size and surface modification on sonocatalytic activity of TiO2 nanoparticles was investigated by measuring the degradation efficiency of methyl orange (MO) as a model pollutant. Crystalline TiO2 nanoparticles with different particles and aggregate size were prepared through solution-phase method with varying synthesis temperatures. Coating with polyvinyl alcohol was performed to enhance colloidal stability of the particles over a wide range of pH values (1.5–7.5). Characterization was carried out using X-ray diffraction, high-resolution transmission electron microscopy, dynamic light scattering, and Fourier-transformed infrared techniques. It was found that... 

    Poly(vinyl alcohol)/graphene oxide mixed matrix membranes for pervaporation of toluene and isooctane

    , Article Polymer - Plastics Technology and Engineering ; Volume 56, Issue 12 , 2017 , Pages 1286-1294 ; 03602559 (ISSN) Khazaei, A ; Mohebbi, V ; Behbahani, R. M ; Ahmad Ramazani, S. A ; Sharif University of Technology
    Poly(vinyl alcohol)/graphene oxide mixed matrix membranes have been prepared and applied for the pervaporation of isooctane (aliphatic) and toluene (aromatic) mixtures. Characteristics of the membranes such as crystallinity, morphology, and swelling have been investigated, and the results have been used to describe pervaporation performance. Experimental tests evidenced that incorporation of low content of graphene oxide nanoplates (0.5 wt%) in poly(vinyl alcohol) increases affinity of the membrane to aromatics by S and π bonds and selectivity increase to about four times. Moreover, interaction of graphene oxide with toluene results in increasing of swelling and decreasing of permeation... 

    Cell life cycle effects of bare and coated superparamagnetic iron oxide nanoparticles

    , Article Toxic Effects of Nanomaterials ; 2012 , Pages 53-66 ; 9781608054213 (ISBN) Mahmoudi, M ; Laurent, S ; Journeay, W. S ; Sharif University of Technology
    Due to the hopeful potential of nanoparticles in medicine, they have attracted much attention for various applications such as targeted drug/gene delivery, separation or imaging. Interaction of NPs with the biological environment can lead to a wide range of cellular responses. In order to have safe NPs for biomedical applications, the current biocompatibility researches are particularly focused on the severe toxic mechanisms which cause cells death. These mechanisms are apoptosis, autophagy and necrosis, which can also be intricately linked with the cell-life cycle, as there are various check-points and controls in a cell's life cycle to ensure appropriate division processes. Mechanisms by... 

    Pervaporation of toluene and iso-octane through poly(vinyl alcohol)/graphene oxide nanoplate mixed matrix membranes: Comparison of crosslinked and noncrosslinked membranes

    , Article Journal of Applied Polymer Science ; Volume 135, Issue 7 , 2018 ; 00218995 (ISSN) Khazaei, A ; Mohebbi, V ; Behbahani, R. M ; Ramazani S. A., A ; Sharif University of Technology
    John Wiley and Sons Inc  2018
    Removal of aromatic compounds from fuel is an essential requirement in new environmental policies. In the present study, poly(vinyl alcohol)/graphene oxide (GO) mixed matrix membranes were prepared and applied to the separation of toluene from iso-octane by pervaporation, considering the similarity and interaction between graphene and aromatics. The effects of crosslinking and GO content on separation efficiency have been investigated in detail. Owing to the high affinity of GO with toluene through s and π bonds, the selectivity of the membranes was increased by incorporating a low amount of GO. The results also indicated that noncrosslinked membranes have higher selectivity and permeation... 

    Antioxidant, antifungal, water binding, and mechanical properties of poly(vinyl alcohol) film incorporated with essential oil as a potential wound dressing material

    , Article Journal of Applied Polymer Science ; Vol. 131, issue. 20 , 2014 Kavoosi, G ; Nateghpoor, B ; Dadfar, S. M. M ; Dadfar, S. M. A ; Sharif University of Technology
    In this study, the properties of poly (vinyl alcohol)(PVA) films incorporated with Zataria multiflora essential oil (ZMO) as a potential antioxidant/antibacterial material was investigated. PVA films were prepared from PVA solutions (2% w/v) containing different concentrations of ZMO. Water solubility, moisture absorption, water swelling, and water vapor permeability for pure PVA films were 57 ± 1.1, 99 ± 3.2%, 337 ± 8%, and 0.453 ± 0.015 g mm/m2 h, respectively. Incorporation of ZMO into PVA films caused a significant decrease in water swelling and moisture absorption and increase in solubility and water vapor permeability. Tensile strength, elastic modulus, and elongation at break for pure... 

    Polyvinyl alcohol and polyvinyl alcohol/ polyvinyl pyrrolidone biomedical foams crosslinked by gamma irradiation

    , Article Journal of Cellular Plastics ; Volume 53, Issue 4 , 2017 , Pages 359-372 ; 0021955X (ISSN) Sabourian, P ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
    SAGE Publications Ltd  2017
    Foams for biomedical applications were made from polyvinyl alcohol, polyvinyl alcohol / polyvinyl pyrrolidone blend and their nanocomposites with nanoclay by clean processes. Air was entrapped into the aqueous polymer solutions during vigorous mixing and then the solutions were freeze-dried. The foams structure was stabilized by crosslinking via gamma irradiation without using any harmful chemicals. The hydrophilic biocompatible foams possessed interconnected open cell structure with remarkable capacity to absorb and retain water. The foams in wet state were soft and flexible. Desirable pore structure and higher water absorption was obtained at a solution concentration of 5 wt% for both... 

    Heterogeneities in polymer structural and dynamic properties in graphene and graphene oxide nanocomposites: molecular dynamics simulations

    , Article Macromolecular Theory and Simulations ; Volume 26, Issue 2 , 2017 ; 10221344 (ISSN) Azimi, M ; Mirjavadi, S. S ; Salem Hamouda, A. M ; Makki, H ; Sharif University of Technology
    Wiley-VCH Verlag  2017
    The effect of graphene (G) and graphene oxide (GO), used as the nanofiller in polymer nanocomposites (NC), on the structural and dynamic properties of polymer chains, has been studied by means of molecular dynamics (MD) simulations. Two polymers, i.e., poly(propylene) and poly(vinyl alcohol), are employed as matrices to cover a wider range of polymer–filler interactions. The local structural properties, e.g., density profile, average Rg, and end-to-end distance as well as dynamic properties, e.g., estimated translational and orientational relaxation times, of polymer chains are studied. In addition, the interaction energies are estimated between polymers and nanofillers for different hybrid... 

    Poly (vinyl alcohol)/nano-diamond composite films and hydrogels prepared by gamma ray

    , Article Journal of Polymer Engineering ; Volume 38, Issue 9 , 2018 , Pages 857-862 ; 03346447 (ISSN) Frounchi, M ; Dadbin, S ; Haddadi, S ; Sharif University of Technology
    De Gruyter  2018
    Poly (vinyl alcohol) and nano-diamond, PVA/ND, hydrogels were prepared and assessed as prosthetic material suitable for replacement of the nucleus pulposus. The hydrogels were prepared by gamma irradiation at various doses (15 kGy, 25 kGy, 35 kGy, 45 kGy) and at various ND concentrations ranging from 0.25 wt.% to 3 wt.%. Extent of gelation, equilibrium water content, and viscoelastic properties of swelled hydrogels at definite water contents were measured and examined as a function of ND concentration as well as gamma dose. According to viscoelastic measurements, the strength of hydrogels increased considerably over that of pure PVA at a low concentration of ND. By increasing irradiation... 

    Barrier improvement of the biaxial oriented polypropylene films using passive mechanisms

    , Article Journal of Materials Research and Technology ; Volume 8, Issue 3 , 2019 , Pages 2987-2995 ; 22387854 (ISSN) Shayanipour, H. R ; Bagheri, R ; Sharif University of Technology
    Elsevier Editora Ltda  2019
    Barrier properties of the biaxial oriented polypropylene (BOPP) films are the most important properties in food packaging industry. In this study different compatibilizers and materials were examined in order to find an appropriate blend composition to minimize the oxygen permeability of the films. It was observed that using organoclay and nanocomposits have positive effect on the oxygen permeability although the kind of compatibilizer is important. Through all evaluated materials the PVA (Poly(vinyl alcohol)) and MA (Maleic Anhydride) were the most successful selection for this goal. The BOPP film blended by PVA achieved the lowest oxygen transfer rate (300 cc 20 μm/m2 24 h atm) in compared... 

    Poly (vinyl alcohol)/graphene oxide nanocomposite films and hydrogels prepared by gamma ray

    , Article Plastics, Rubber and Composites ; Volume 48, Issue 2 , 2019 , Pages 42-47 ; 14658011 (ISSN) Frounchi, M ; Dadbin, S ; Tabatabaei, M ; Sharif University of Technology
    Taylor and Francis Ltd  2019
    Poly (vinyl alcohol)/graphene oxide (PVA/GO) gamma irradiated nanocomposite films and hydrogels were prepared. In composite films, GO was initially irradiated by gamma ray in order to improve interactions between GO and PVA. The film containing 1 wt-% GO was very strong where tensile modulus and tensile yield strength were 45 and 115% higher than those of pure PVA. In the second set of experiments PVA/GO hydrogels were made by irradiating PVA/GO suspensions by gamma ray at various doses. It was an interesting finding that GO increased the gel portion of hydrogels through contribution of H-bonds between PVA and GO. The hydrogels prepared at 20 kGy had remarkable water swelling ratio that... 

    Modeling of viscoelastic fluid flow behavior in the circular die using the leonov-like conformational rheological constitutive equations

    , Article Macromolecular Symposia ; Volume 274, Issue 1 , 2008 , Pages 6-10 ; 10221360 (ISSN) Ramazani, A ; Kanvisi, M ; Sharif University of Technology
    In this paper, the flow behavior of Leonov-Like conformational rheological model, which has root in the generalized Poisson bracket formalism based on the conformation tensor, have been studied in the circular die flow. Prediction of the normal stress differences during the flow of these fluids lets us to follow and calculate relaxation dependent phenomena such as die swell. The model predictions have been compared for the four families of mobility expressions. The Study of the model prediction sensitivity to its mobility term shows that model predictions can cover a wide range of rheological behaviors generally observed for polymer melts and solutions in the circular die flow. Copyright ©... 

    Nano-magnetic poly (vinyl alcohol) hydrogels

    , Article Advanced Materials Research ; Volume 829 , 2014 , Pages 539-543 ; ISSN: 10226680 ; ISBN: 9783037859070 Asadi, S ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
    Surface modified magnetic nanoparticles (M-NPs) were synthetized and stabilized in poly (vinylalcohol) solution. The solutions with various magnetic nanoparticles contents were gammairradiated and magnetic poly (vinyl-alcohol) (M-PVA) hydrogels were synthesized. The magnetic hydrogels and also the un-irradiated magnetic poly (vinyl alcohol) nanocomposite films were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectroscopy (FTIR) and mechanical measurement. The M-NPs were uniformly dispersed in the polymer matrix due to a strong interaction between the surface-modified M-NPs and polymer matrix.... 

    Investigation of mechanical properties, antibacterial features, and water vapor permeability of polyvinyl alcohol thin films reinforced by glutaraldehyde and multiwalled carbon nanotube

    , Article Polymer Composites ; Vol. 35,Issue. 9 , 2014 , pp. 1736-1743 ; ISSN: 1548-0569 Mohammad Mahdi Dadfar, S ; Kavoosi, G ; Mohammad Ali Dadfar, S ; Sharif University of Technology
    Polyvinyl alcohol (PVA) thin films were reinforced by glutaraldehyde and multiwalled carbon nanotubes (MWCNTs) and then mechanical, water solubility, water swelling, water uptake, water vapor permeability, and antibacterial properties of the films were examined. Cross-linking by glutaraldehyde or incorporation of MWCNT caused a significant increase in tensile strength, decrease in elongation at break, and increase in Young's modulus of the PVA films, while MWCNTs were more effective rather than that of glutaraldehyde. Cross-linking by glutaraldehyde or incorporation of MWCNT caused a significant decrease in water solubility, water swelling and water uptake, with a similar manner.... 

    Experimental investigation of operating conditions for preparation of PVA-PEG blend membranes using supercritical CO2

    , Article Journal of Supercritical Fluids ; Vol. 95 , November , 2014 , pp. 603-609 ; ISSN: 08968446 Taji, S ; Nejad-Sadeghi, M ; Goodarznia, I ; Sharif University of Technology
    Poly(vinyl alcohol)-polyethylene glycol, PVA-PEG, blended membrane were prepared using supercritical fluid assisted phase-inversion method, in which scCO2 was used as the anti-solvent. Poly(vinyl alcohol) was utilized as the main polymer, polyethylene glycol as the additive, and dimethyl sulfoxide (DMSO) as the solvent of these polymers. Taguchi method was used to investigate the effect of some operating parameters on the morphology of the membranes. The L16 orthogonal array was selected under the following conditions: pressure (100, 135, 165 and 200 bar), temperature (40, 45, 50 and 55°C) and PEG weight percent (0, 0.33, 0.66, and 1%). Total polymer concentration of solutions in all... 

    Preparation of PVA nanocomposites using salep-reduced graphene oxide with enhanced mechanical and biological properties

    , Article RSC Advances ; Volume 5, Issue 112 , 2015 , Pages 92428-92437 ; 20462069 (ISSN) Pourjavadi, A ; Pourbadiei, B ; Doroudian, M ; Azari, S ; Sharif University of Technology
    Royal Society of Chemistry  2015
    Salep, known as a biodegradable polysaccharide, is hydrolyzed and used as both a reducing agent and stabilizer for graphene oxide (GO). The functionalized reduced graphene oxide (f-rGO) is homogenously dispersed in an aqueous solution of poly(vinyl alcohol) (PVA). PVA based hydrogel and film nanocomposites are prepared and proposed as new biomaterials for tissue engineering applications. The mechanical properties of the film nanocomposites are investigated with varying content of f-rGO, glycerol and citric acid as a reinforcing agent, a plasticizer agent and a cross linking agent respectively. For the first time, chemically cross linked PVA hydrogels are synthesized using... 

    A flow injection μ-solid phase extraction system based on electrospun polyaniline nanocomposite

    , Article Journal of Chromatography A ; Volume 1433 , February , 2016 , Pages 34–40 ; 00219673 (ISSN) Bagheri, H ; Khanipour, P ; Roostaie, A ; Sharif University of Technology
    In this study, a fast and sensitive flow injection μ-solid phase extraction (FI-μ-SPE) technique based on an electrospun polyaniline (PANI) nanocomposite in conjunction with gas chromatography-mass spectrometry (GC-MS) was developed. The PANI-based nanocomposite was synthesized by electrospinning of a solution containing polyvinyl alcohol (PVA)/PANI. The majority of PVA template was subsequently removed from the whole PVA/PANI nanofibers blend by exposing the electrospun nanocomposite to hot water. The homogeneity, porosity and characterization of the electrospun nanofibers were investigated by the scanning electron microscopy (SEM) and Fourier transform infrared (FT-IR) spectroscopy. Due to... 

    Effect of gamma ray on magnetic bio-nanocomposite

    , Article Materials Chemistry and Physics ; Volume 170 , 2016 , Pages 71-76 ; 02540584 (ISSN) Asadi, S ; Frounchi, M ; Dadbin, S ; Sharif University of Technology
    Elsevier Ltd  2016
    Magnetic polyvinyl alcohol (M-PVA) films were prepared via solution casting filled with surface modified superparamagnetic nanoparticles (M-NPs). The M-NPs were coated with citric acid during synthesis. The chemical interaction between the citric acid and M-NPs was confirmed by Fourier transform infrared spectroscopy (FTIR). The average hydrodynamic diameter of M-NPs was 19.7 nm measured by dynamic light scattering DLS and appeared almost spherical in scanning electron microscopy (SEM). The M-NPs were uniformly dispersed in polyvinyl alcohol (PVA) matrix and showed high optical transparency with good mechanical properties. M-PVA hydrogels were synthesized using gamma irradiation. The... 

    Preparation of electrospun affinity membrane and cross flow system for dynamic removal of anionic dye from colored wastewater

    , Article Fibers and Polymers ; Volume 18, Issue 12 , 2017 , Pages 2387-2399 ; 12299197 (ISSN) Hosseini, S. A ; Vossoughi, M ; Mahmoodi, N. M ; Sharif University of Technology
    In this research, poly(vinyl alcohol) (PVA)/chitosan electrospun nanofibrous membrane (ENM) was prepared by electrospinning method in order to investigate its dye removal ability from colored wastewater. The morphology and average fiber diameter of the membranes were investigated by scanning electron microscopy (SEM), image analysis and atomic force microscopy (AFM). The chemical characterization was studied by Fourier transform infrared spectroscopy (FTIR). The permeability of the membranes was evaluated by measuring pure water flux (PWF). In order to investigate the performance of the prepared membranes they were used in the batch adsorption and membrane separation for dye removal from... 

    Curcumin incorporated PVA-borax dual delivery hydrogels as potential wound dressing materials—Correlation between viscoelastic properties and curcumin release rate

    , Article Journal of Applied Polymer Science ; Volume 135, Issue 45 , 2018 ; 00218995 (ISSN) Rezvan, G ; Pircheraghi, G ; Bagheri, R ; Sharif University of Technology
    John Wiley and Sons Inc  2018
    Poly(vinyl alcohol) (PVA) is a biocompatible polymer which can be physically crosslinked by Borax to form hydrogel. PVA-Borax (PB) hydrogel is a promising candidate for drug delivery system. Therefore, it is necessary to find the quantitative relationship between drug release rate and network structure of PB hydrogels to predict and control drug release rate. In this work, at first step the optimum ratio of Borax: PVA was determined by studying the interactions between PVA chains and Borax molecules by means of Fourier transform infrared spectroscopy, while viscoelastic properties of prepared PB hydrogels were measured in the oscillatory shear flow field. In the following, curcumin as a...