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hydrogels
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Hydrogel nanocomposite based on chitosan-g-acrylic acid and modified nanosilica with high adsorption capacity for heavy metal ion removal
, Article Iranian Polymer Journal (English Edition) ; Volume 24, Issue 9 , September , 2015 , Pages 725-734 ; 10261265 (ISSN) ; Mazaheri Tehrani, Z ; Salimi, H ; Banazadeh, A ; Abedini, N ; Sharif University of Technology
Springer-Verlag London Ltd
2015
Abstract
In this study, a novel hybrid hydrogel based on chitosan, acrylic acid and amine-functionalized nanosilica was prepared and characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy. This hydrogel nanocomposite was used for removal of Co2+, Cu2+, Pb2+ and Zn2+ ions from aqueous solution. The metal ion adsorption was measured by inductively coupled plasma mass spectrometry. The adsorption behavior showed that the presence of modified nanosilica enhanced the porosity of the hydrogel network and affected its adsorption capacity in response to different parameters such as nanosilica content, metal ion concentration, adsorbent content,...
Magnetic graphene oxide mesoporous silica hybrid nanoparticles with dendritic pH sensitive moieties coated by PEGylated alginate-co-poly (acrylic acid) for targeted and controlled drug delivery purposes
, Article Journal of Polymer Research ; Volume 22, Issue 8 , 2015 ; 10229760 (ISSN) ; Shakerpoor, A ; Tehrani, Z. M ; Bumajdad, A ; Sharif University of Technology
Kluwer Academic Publishers
2015
Abstract
In this study synthesis of a drug delivery system (DDS) is described which has several merits over its counterparts. In order to synthesize this nano-carrier, graphene oxide nano-sheets are used to accommodate MCM-41 nanoparticles. Furthermore Fe3 O4 nanoparticles are introduced to this nano-material to produce a traceable nanoparticle. Since cancerous tissues have lower pH than healthy tissues, pH-sensitive oligomers are attached to this nano-material. Finally the nano-carrier is wrapped by a biocompatible shell (PEGylated sodium alginate); this polymeric shell makes the DDS capable of a more controllable drug release. By measuring in vitro situation, ‘loading content%’...
Structure, swelling and mechanical behavior of a cationic full-IPN hydrogel reinforced with modified nanoclay
, Article Iranian Polymer Journal (English Edition) ; Volume 24, Issue 5 , May , 2015 , Pages 379-388 ; 10261265 (ISSN) ; Bagheri, R ; Kabiri, K ; Sharif University of Technology
Springer-Verlag London Ltd
2015
Abstract
Despite various applications of hydrogels, they have poor gel strength and low resistance against crack propagation which lead to the limitation of their applications. For overcoming this inherent weakness, the current study has focused on the simultaneous utilization of interpenetrating polymer network (IPN) structure and nanocomposite hydrogels. It is known that IPN and nanocomposite gels can improve gel strength. The combination of IPN and nanocomposite structure was developed in hydrogels for improving gel strength. For this purpose, bentonite was successfully modified with a cationic surfactant, (3-methacrylamidopropyl) trimethyl ammonium chloride (MAPTAC), as intercalate, and...
Inhomogeneous swelling behavior of temperature sensitive PNIPAM hydrogels in micro-valves: Analytical and numerical study
, Article Smart Materials and Structures ; Volume 24, Issue 4 , February , 2015 ; 09641726 (ISSN) ; Baghani, M ; Naghdabadi, R ; Sohrabpour, S ; Sharif University of Technology
Institute of Physics Publishing
2015
Abstract
In this work, inhomogeneous swelling of the temperature-sensitive PNIPAM hydrogel is investigated with application to micro-valves. In this regard, a modified model is considered, and an analytical solution of the inhomogeneous swelling of a hydrogel jacket coated on a rigid pillar is performed, which is valuable for the conceptual design of the micro-valve. Then, finite element implementation of the modified model is carried out, and its validity is verified by both the analytical and experimental results. Thereafter, thermo-mechanical behavior of the micro-valve is investigated considering the coupling between the inhomogeneous swelling of the jacket and contact problems due to the...
Chitosan-gelatin sheets as scaffolds for muscle tissue engineering
, Article Artificial Cells, Nanomedicine and Biotechnology ; Volume 43, Issue 2 , Nov , 2015 , Pages 124-132 ; 21691401 (ISSN) ; Mashayekhan, S ; Nazaripouya, A ; Naji, M ; Hunkeler, D ; Rajabi Zeleti, S ; Sharifiaghdas, F ; Sharif University of Technology
Informa Healthcare
2015
Abstract
Hydrogels made of natural polymers [chitosan (CS) and gelatin (G)] have been prepared having mechanical properties similar to those of muscle tissues. In this study, the effect of polymer concentration and scaffold stiffness on the behavior of seeded muscle-derived cells (MDCs) on the CS-G hydrogel sheets has been evaluated. Both variables were found to be important in cell viability. Viability was assessed by observation of the cell morphology after 1 day as well as a 14-day MTT assay. The CS-G hydrogels were characterized using Fourier transform infrared (FTIR) analysis, which revealed evidences of strong intermolecular interactions between CS and G. Hydrogel samples with intermediate...
Swelling and mechanical behavior of nanoclay reinforced hydrogel: single network vs. full interpenetrating polymer network
, Article Polymer Bulletin ; Volume 72, Issue 7 , March , 2015 , Pages 1663-1681 ; 01700839 (ISSN) ; Bagheri, R ; Kabiri, K ; Sharif University of Technology
Springer Verlag
2015
Abstract
Despite the various uses of hydrogels, one of their weaknesses is the poor gel strength. To overcome this restriction, the current study has focused on simultaneously employing an interpenetrating polymer network (IPN) structure and nanocomposite hydrogels. Through this approach, the influence of nanofiller in the single network and IPN hydrogel properties was also studied in detail. For this purpose, a novel full interpenetrating polymer network (IPN) hydrogel nanocomposite based on 2-acrylamido-2-methylpropane sulfonic acid (AMPS)/acrylic acid (AA)–sodium acrylate (AANa) was synthesized in two steps through a facile solution polymerization with incorporation of modified bentonite (MBE) as...
Design and Fabrication of Hydrogel Microcarrier for Tissue Engineering
, M.Sc. Thesis Sharif University of Technology ; Mashayekhan, Shohre (Supervisor) ; Yaghmaei, Soheila (Supervisor)
Abstract
Microcarriers (MCs) are an attractive technology with various applications in tissue engineering. In this study, chitosan/gelatin MCs were fabricated with blends of different ratio of chitosan/gelatin, by using a setup containing high voltage electrostatic field and syringe pump. Optimization of blend ratio, voltage and syringe pump flow carried out by the “Design expert” software leads to fabrication of MCs with constant diameter while having various elasticity. Mechanical strength and elasticity of MCs were determined. Human umbilical cord mesenchymal stem cells (hUCMSCs) were cultured on MCs dynamically by using mini-rocher in an incubator. Cells adhesion on MCs were successfully shown by...
Transport in droplet-hydrogel composites: response to external stimuli
, Article Colloid and Polymer Science ; Volume 293, Issue 3 , March , 2015 , Pages 941-962 ; 0303402X (ISSN) ; Sharif University of Technology
Springer Verlag
2015
Abstract
Determination of effective transport properties of droplet-hydrogel composites is essential for various applications. The transport of ions through a droplet-hydrogel composite subjected to an electric field is theoretically studied as an initial step toward quantifying the effective transport properties of droplet-hydrogel composites. A three-phase electrokinetic model is used to derive the microscale characteristics of the polyelectrolyte hydrogel, and the droplet is considered an incompressible Newtonian fluid. The droplet-hydrogel interface is modeled as a surface, which encloses the interior fluid. The surface has the thickness of zero and the electrostatic potential ζ. Standard...
Synthesis of magnetic graphene oxide-containing nanocomposite hydrogels for adsorption of crystal violet from aqueous solution
, Article RSC Advances ; Volume 5, Issue 41 , Mar , 2015 , Pages 32263-32271 ; 20462069 (ISSN) ; Nazari, M ; Hosseini, S. H ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
Magnetic nanocomposite hydrogels containing different amounts of graphene oxide were synthesized and characterized by FTIR, XRD, TGA, SEM, TEM, VSM and UV-vis spectroscopy. The prepared hydrogels were used as adsorbents for removal of a cationic dye, crystal violet, from water. The kinetics and isotherm of adsorption and the effect of different experimental conditions such as graphene oxide content, pH of the solution, contact time, adsorbent dosage and initial dye concentration on adsorption capacity were then investigated. Parameters related to kinetics and isotherm models were calculated and discussed. It was found that adsorption is well-described by pseudo-second-order kinetics and...
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) ; Pourbadiei, B ; Doroudian, M ; Azari, S ; Sharif University of Technology
Royal Society of Chemistry
2015
Abstract
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...
Improvement in mechanical performance of anionic hydrogels using full-interpenetrating Polymer Network Reinforced with Graphene Oxide Nanosheets
, Article Advances in Polymer Technology ; 2015 ; 07306679 (ISSN) ; Bagheri, R ; Kabiri, K ; Ossipov, D. A ; Jokar, E ; Asadian, E ; Sharif University of Technology
John Wiley and Sons Inc
2015
Abstract
Weak mechanical possession is one of the limiting factors in application of hydrogels. To modify this inherent disadvantage, different approaches have been studied including synthesizing interpenetrating polymer network (IPN) and nanocomposite hydrogels. So, this study has focused on preparation of a novel full-IPN structure based on anionic monomers of 2-acrylamido-2-methylpropane sulfonic acid/acrylic acid-sodium acrylate via facile solution polymerization technique in an aqueous media with incorporation of graphene oxide (GO) nanosheets. Mechanical performance of materials in the "as-prepared condition" and "swollen state" was characterized via tensile, compression, and rheology tests,...
Synthsis of Modified Graphene Nanocomposites Based on Biodegredable Polymers and Investigation of Their Mechanical، Electrochemical and Biological Properties
, M.Sc. Thesis Sharif University of Technology ; Pourjavadi, Ali (Supervisor)
Abstract
Graphene، a molecular single layer of graphite، has tremendous applications in materials science for the development of nanocomposites، tissue engineering and supercapacitors. Graphene application and its developing applications depend on its essential properties such as excellent mechanical and thermal properties. Accordingly، investigation on graphene has drawn significant attention to itself. Hence، exploitation of these important properties including the induction of graphene sheets in polymer matrix seems to be essential. In the present survey، salep، a biodegradable polysaccharide، has been used for either the reduction of graphene oxide or functionalization of graphene. Then، reduced...
Semi-IPN carrageenan-based nanocomposite hydrogels: Synthesis and swelling behavior
, Article Journal of Applied Polymer Science ; Volume 118, Issue 5 , 2010 , Pages 2989-2997 ; 00218995 (ISSN) ; Marandi, G. B ; Pourjavadi, A ; Kiani, G ; Sharif University of Technology
2010
Abstract
Inclusion of nano-clays into hydrogels is an efficient approach to produce nanocomposite hydrogels. The introduction of nano-clay into hydrogels causes an increase in water absorbency. In the present work, Nanocomposite hydro-gels based on kappa-carrageenan were synthesized using sodium montmorillonite as nano-clay. Acrylamide and meth-ylenebisacrylamide were used as monomer and crosslinker, respectively. The structure of nanocomposite hydrogels was investigated by XRD and SEM techniques. Swelling behavior of nanocomposite hydrogels was studied by varying clay and carrageenan contents as well as methylenebisacrylamide concentration. An optimum swelling capacity was achieved at 12% of sodium...
Synthesis and properties of partially hydrolyzed acrylonitrile-co- acrylamide superabsorbent hydrogel
, Article Bulletin of the Korean Chemical Society ; Volume 31, Issue 11 , 2010 , Pages 3163-3172 ; 02532964 (ISSN) ; Hosseinzadeh, H ; Sharif University of Technology
2010
Abstract
In this work, a novel method to synthesis of an acrylic superabsorbent hydrogel was reported. In the two stage hydrogel synthesis, first copolymerization reaction of acrylonitrile (AN) and acrylamide (AM) monomers using ammonium persulfate (APS) as a free radical initiator was performed. In the second stage, the resulted copolymer was hydrolyzed to produce carboxamide and carboxylate groups followed by in situ crosslinking of the polyacrylonitrile chains. The results from FTIR spectroscopy and the dark red-yellow color change show that the copolymerization, alkaline hydrolysis and crosslinking reactions have been do take place. Scanning electron microscopy (SEM) verifies that the synthesized...
Alginate-based biodegradable superabsorbents as candidates for diclofenac sodium delivery systems
, Article Journal of Applied Polymer Science ; Volume 118, Issue 4 , 2010 , Pages 2015-2023 ; 00218995 (ISSN) ; Zeidabadi, F ; Barzegar, Sh ; Sharif University of Technology
2010
Abstract
Novel types of highly swelling hydrogels were prepared by grafting crosslinked polyacrylamide-co-poly-2-acrylamido-2-methylpropane sulfonic acid (PAAm-co-PAMPS) chains onto sodium alginate (Na-Alg) through a free radical polymerization method. The superabsorbent formation was confirmed by Fourier transform infrared spectroscopic (FTIR). The controlled release behavior of diclofenac sodium (DS) from superabsorbent polymer was factinvestigated, and shown that the release profiles of DS from superabsorbent polymer were slow in simulated gastric fluid (SGF, pH 1.2) over 3 h, but nearly all of the initial drug content was released in simulated intestinal fluid (SIF, pH 7.4) within 21 h after...
New smart carrageenan-based superabsorbent hydrogel hybrid: Investigation of swelling rate and environmental responsiveness
, Article Journal of Applied Polymer Science ; Volume 117, Issue 6 , September , 2010 , Pages 3228-3238 ; 00218995 (ISSN) ; Pourjavadi, A ; Seidi, F ; Eftekhar Jahromi, P ; Soleyman, R ; Sharif University of Technology
2010
Abstract
Synthesis of novel natural-based superabsorbents with improved properties is of prime importance in many applications. In this article we report an efficient synthesis of new polysaccharide-based superabsorbent hybrid composing carrageenan, acrylic acid, sodium acrylate, and 2-hydroxyethyl acrylate through homogenous solution polymerization process. Infrared spectroscopy and thermogravimetric analysis (TGA) were carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy (SEM). To deeper studies on the structure-property relation in SAP hydrogels, three hydrogels with different acrylic acid/2-hydroxyethyl...
CMC/celite superabsorbent composites: Effect of reaction variables on saline-absorbency under load
, Article Iranian Polymer Journal (English Edition) ; Volume 19, Issue 8 , May , 2010 , Pages 571-579 ; 10261265 (ISSN) ; Soleyman, R. A ; Ghasemzadeh, H ; Salimi, H ; Sharif University of Technology
Abstract
A series of superabsorbent composites were synthesized through graft copolymerization of acrylic acid (AA) onto carboxymethyl cellulose (CMC) in the presence of celite powder using N,N'-methylenebisacrylamide (MBA) as a cross-linking agent and ammonium persulphate (APS) as an initiator. The chemical structure and thermal properties of the composite hydrogels were characterized by FTIR spectroscopy and TGA methods, respectively. Morphology of the samples was examined by scanning electron microscopy (SEM). In free-state, the swelling conditions and hence the related data are not real, because in all their applications the swelling particles of superabsorbent must absorb aqueous solutions while...
Gamma irradiation mediated synthesis of a new superabsorbent hydrogel network based on poly(acrylic acid) grafted onto salep
, Article Journal of the Iranian Chemical Society ; Volume 7, Issue 3 , 2010 , Pages 652-662 ; 1735207X (ISSN) ; Pourjavadi, A ; Soleyman, R ; Sheikh, N ; Sharif University of Technology
2010
Abstract
A novel and smart biopolymer-based hydrogel was synthesized by graft copolymerization of acrylic acid onto the salep backbones. The new superabsorbent hydrogel was synthesized via simultaneous crosslinking and graft copolymerization of acrylic acid (AA) monomer onto salep backbones using radiochemical methods. In radiochemical methods, γ-rays as initiator, energy source and crosslinker are applied. In our experiments, the effects of reaction variables such as relative contents of salep and AA, as well as γ-rays total dose were examined. According to water absorbency of the entitled network, the best synthesis condition is reported. FTIR spectroscopy, SEM photograph and TGA analysis were used...
Modified chitosan as a polymeric nanoreactor for fabrication of pure zno nano particles
, Article Journal of Applied Polymer Science ; Volume 117, Issue 2 , March , 2010 , Pages 1035-1040 ; 00218995 (ISSN) ; Barzegar, S ; Pourjavadi, A ; Sharif University of Technology
2010
Abstract
ZnO nanoparticles have been prepared successfully by hydrogel decomposition method (HDM). Synthesized ZnO nanoparticles were characterized by X-ray diffraction (XRD), fourier transforms infrared spectroscopy (FTIR), and transition electron microscopy (TEM) techniques. Narrow distribution of sizes with a 20-30 nm diameter and regular distribution of ZnO nanoparticles are attributed to the application of poly(acrylic acid-co-acrylamide) grafted chitosan hydrogel as coating agent. The results show that the polymer thermal decomposition technique is a perfect method for the synthesis of ZnO nano particles
γ-irradiation synthesis of a smart hydrogel: Optimization using taguchi method and investigation of its swelling behavior
, Article Scientia Iranica ; Volume 17, Issue 1 C , June , 2010 , Pages 15-23 ; 10263098 (ISSN) ; Soleyman, R ; Bardajee, Gh. R ; Seidi, F ; Sharif University of Technology
2010
Abstract
In the current work, synthesis of an environmental-sensitive superabsorbent hydrogel using γ-rays is described. Grafted polyacrylonitrile onto a homogeneous solution of starch and kappa-Carrageenan hybrid backbones created a smart material with reversible behavior. The reaction parameters (i.e. acrylonitrile, starch and kappa-Carrageenan concentration, as well as γ-irradiation time) affecting the. water absorbency of the. hydrogel were optimized using the. Taguchi method, in order to achieve a hydrogel with high swelling capacity. FTIR spectroscopy was used for confirming the. structure of the final product and the morphology of the synthesized hydrogel was examined by a scanning electron...