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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) ; Dadbin, S ; Tabatabaei, M ; Sharif University of Technology
Taylor and Francis Ltd
2019
Abstract
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...
Dual-diffusivity stochastic model for macromolecule release from a hydrogel
, Article ACS Applied Bio Materials ; Volume 3, Issue 7 , 2020 , Pages 4208-4219 ; Lau, C. M. L ; Abdekhodaie, M. J ; Chau, Y ; Sharif University of Technology
American Chemical Society
2020
Abstract
A three-dimensional model has been developed to describe the multiphase release of macromolecular drugs encapsulated in a hydrogel. The heterogeneity of network mesh size was considered by assigning varying diffusion coefficients to the network lattices randomly. Using a stochastic approach, the random nature of diffusion of drug molecules was captured within the network. The simplest form of distribution containing two diffusion coefficients was tested. To generate the drug release profiles for experimental validation under the limitation of computational cost, a simple scaling relationship was employed. Unlike the single-diffusivity model, the dual-diffusivity model showed good agreement...
Hydrolyzed collagen-based hydrogel with salt and pH-responsiveness properties
, Article Journal of Applied Polymer Science ; Volume 106, Issue 4 , 2007 , Pages 2371-2379 ; 00218995 (ISSN) ; Salimi, H ; Kurdtabar, M ; Sharif University of Technology
2007
Abstract
A novel hydrolyzed collagen-based hydrogel has been prepared by grafting the binary mixture of acrylamide and 2-acrylamido-2-methylpropanesulfonic acid onto the collagen backbone in the presence of a cross-linking agent. Its physicochemical properties in aqueous solution were studied. The effect of reaction variables on both gel content and swelling capacity was investigated to achieve a hydrogel with improved absorbency and gel content. The absorbency under load of optimized hydrogel was also investigated by using an absorbency under load tester at various applied pressures. The swelling ratio in various salt solutions was also determined and additionally, the swelling of hydrogels was...
Modified CMC. V. synthesis and super-swelling behavior of hydrolyzed CMC-g-PAN hydrogel
, Article Journal of Applied Polymer Science ; Volume 103, Issue 2 , 2007 , Pages 877-883 ; 00218995 (ISSN) ; Zohuriaan Mehr, M. J ; Ghasempoori, S. N ; Hossienzadeh, H ; Sharif University of Technology
2007
Abstract
Polyacrylonitrile (PAN) was grafted onto carboxymethyl cellulose (CMC) sodium salt backbones by using cerie ammonium nitrate (CAN) as an initiator. The graft co-polymer, CMC-g-PAN, was hydrolyzed by NaOH solution to yield hydrogel, H-CMC-g-PAN. The nitrile groups of CMC-g-PAN were completely converted to a mixture of hydrophilic carboxamide and carboxylate groups during alkaline hydrolysis, followed by in situ crosslinking of the grafted PAN chains. The structure of the products was confirmed by FTIR spectroscopy. The synthetic parameters affecting the swelling capacity of the hydrogel (i.e., CMC-g-PAN add-on value, the hydrolysis time and temperature, and concentration of NaOH) were...
The impact of zirconium oxide nanoparticles content on alginate dialdehyde-gelatin scaffolds in cartilage tissue engineering
, Article Journal of Molecular Liquids ; Volume 335 , 2021 ; 01677322 (ISSN) ; Salavati Niasari, M ; Mohandes, F ; Firouzi, Z ; Mousavi, S.-D ; Sharif University of Technology
Elsevier B.V
2021
Abstract
The desire to regenerate and repair native tissues can be immediately performed by multiple tissue engineering procedures. Gelatin and alginate are biocompatible and biodegradable polymers. The addition of ZrO2 nanoparticles (NPs) into the alginate-gelatin hydrogel is considered to improve mechanical and chemical properties. Therefore, nanocomposite hydrogels have been manufactured by the freeze-drying procedure utilizing oxidized alginate-gelatin with ZrO2 NPs as a reinforcement. The fabricated nanocomposite hydrogels were character-ized by FTIR, FESEM, and rheometer. The hydrogels containing a higher ZrO2 NPs content (1.5%) have better mechanical properties than the hydrogels without NPs....
A review on catalytic reduction/degradation of organic pollution through silver-based hydrogels
, Article Arabian Journal of Chemistry ; Volume 15, Issue 9 , 2022 ; 18785352 (ISSN) ; Ali Ghasemzadeh, M ; Alipour, S ; Zamani, F ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Various challenging pollutants are produced in the environment by organic materials of diverse industries including leather, paint, and textile. Nowadays, it is vital to develop efficient manners regarding the fundamental issues and removing pollutants. Such pollutants can be effectively removed from the environment through heterogeneous catalysts. Recently, a huge deal of interest has been attracted by hydrogel-based metal catalysts as heterogeneous and efficient catalysts. In this regard, silver with its unique features is suitable for environmental remediation. Hence, the present review deals with summarizing the present advances in the synthesis of silver-based hydrogel catalysts, as...
Experimental evaluation of a solar-driven adsorption desalination system using solid adsorbent of silica gel and hydrogel
, Article Environmental Science and Pollution Research ; Volume 29, Issue 47 , 2022 , Pages 71217-71231 ; 09441344 (ISSN) ; Behshad Shafii, M ; Ebrahimpour, B ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2022
Abstract
Nowadays, the world is facing a shortage of fresh water. Utilizing adsorbent materials to adsorb air moisture is a suitable method for producing freshwater, especially combining the adsorption desalination system with solar energy devices such as solar collectors. The low temperature of solar collectors has caused some water to remain in the adsorbents in the desorption process and has reduced the possibility of using these systems. In this research, for the first time, an evacuated tube collector (ETC) is used as an adsorbent bed so that the temperature of the desorption process reaches higher values and as a result, more fresh water is expected to produced. In this study, two adsorption...
Magnetic carboxymethyl cellulose/silk fibroin hydrogel embedded with halloysite nanotubes as a biocompatible nanobiocomposite with hyperthermia application
, Article Materials Chemistry and Physics ; Volume 287 , 2022 ; 02540584 (ISSN) ; Choopani, L ; Aghamirza Moghim Aliabadi, H ; Ganjali, F ; Kashtiaray, A ; Maleki, A ; Ahangari Cohan, R ; Salimi Bani, M ; Komijani, S ; Ahadian, M. M ; Salehpour, N ; Mahdavi, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
A novel and high potent magnetic nanobiocomposite was prepared based on Carboxymethyl cellulose (CMC) and epichlorohydrin (ECH) cross-linker interactions to form a three-dimensional cross-linked CMC hydrogel followed by silk fibroin (SF) and halloysite nanotubes (HNTs) modifications and further in situ Fe3O4 magnetic nanoparticles (MNPs) formation. Different analytical techniques like FT-IR, EDX, FE-SEM, XRD, TGA, and VSM were used to characterize the structure of the prepared nanobiocomposite. The spherical morphology of Fe3O4 MNPs and tubular HNTs were presented in the FE-SEM images. In biological tests, since the hemolysis percent was even less than the negative control, the CMC...
Effectively exerting the reinforcement of polyvinyl alcohol nanocomposite hydrogel via poly(dopamine) functionalized graphene oxide
, Article Composites Science and Technology ; Volume 217 , 2022 ; 02663538 (ISSN) ; Pircheraghi, G ; Nazockdast, H ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Nature-inspired coating with polydopamine (PDA) is a promising way to improve the performance of graphene oxide (GO) based nanocomposites due to its high ability to enhance interactions in matrix-disperse systems. Here, we examined the capability of two types of PDA to develop the reinforced polyvinyl alcohol (PVA)/GO hydrogels. In the first mode, dopamine hydrochloride was polymerized as nanoparticles and then incorporated into PVA solution with GO nanoplatelets (P-NG hydrogel). In the second mode, polydopamine was polymerized in the presence of GO nanoparticles to obtain PDA surface-modified GO and then PVA nanocomposite hydrogel (P-CG sample). Rheological and tensile findings revealed...
Synthesis, characterization and swelling behavior of chitosan-sucrose as a novel full-polysaccharide superabsorbent hydrogel
, Article Journal of Applied Polymer Science ; Volume 109, Issue 4 , 15 August , 2008 , Pages 2648-2655 ; 00218995 (ISSN) ; Aghajani, V ; Ghasemzadeh, H ; Sharif University of Technology
2008
Abstract
A novel full-polysaccharide hydrogel was prepared by crosslinking of chitosan with periodate-oxidized sucrose. A tetraaldehyde molecule is synthesized via periodate oxidation of sucrose and then applied as a crosslinking agent to form a new hydrogel network. A mechanism for the superabsorbent hydrogel formation via reductive N-alkylation was also suggested. The structure of the hydrogel was confirmed by FTIR spectroscopy, scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). It is shown that crosslinking of chitosan can improve its thermal stability. The effects of crosslinker concentration, pH, and inorganic salt on the swelling behavior of the hydrogel were studied. The...
Mechanical Properties Enhancement of Hydrogel Scaffolds Using Combination of Electrospun Nanofibers
,
M.Sc. Thesis
Sharif University of Technology
;
Mashayekhan, Shohreh
(Supervisor)
Abstract
Cardiovascular disease is responsible for a majority of health problem in developing countries. Heart diseases are the leading cause of death in the United State with approximately 40% of the death occurs by heart failures and coronary artery defects. Myocardial infarction is one of the diseases that occurs by coronay artery blockage. Cardiac tissue engineering (CTE) is an emerging field that holds great promise towards the development of innovative treatment strategies for heart disease. There are two common scaffolds for CTE, electrospun fiber mats and hydrogels. Although fibers are known as 3D environment for cells, they actually act as a 2D surface, because of lack of cell infilteration....
Design and Synthesis of Heterogeneous Nanocatalysts Based on Immobilized Metals on Polymeric Substrates and their Applications in Organic Reactions
, Ph.D. Dissertation Sharif University of Technology ; Pourjavadi, Ali (Supervisor)
Abstract
Today, catalysts have shown the growing applications in chemical industries especially for drug synthesis. Using immobilized heterogeneous catalysts is a sensible way to benefit from advantages of both heterogeneous and homogeneous catalysts. In this regards, homogeneous catalysts are immobilized on to a solid support through various methods. However, low loading amount of homogenous part and subsequently insufficient catalytic activity are main limitations of immobilized heterogeneous catalysts. For this reason, polymeric supports have been introduced to immobilize metal ions or nanoparticles. These polymeric supports not only possess advantages such as anti-corrosive properties, simple...
Smart polymeric hydrogels for cartilage tissue engineering: A review on the chemistry and biological functions
, Article Biomacromolecules ; Volume 17, Issue 11 , 2016 , Pages 3441-3463 ; 15257797 (ISSN) ; Abdorahim, M ; Simchi, A ; Sharif University of Technology
American Chemical Society
Abstract
Stimuli responsive hydrogels (SRHs) are attractive bioscaffolds for tissue engineering. The structural similarity of SRHs to the extracellular matrix (ECM) of many tissues offers great advantages for a minimally invasive tissue repair. Among various potential applications of SRHs, cartilage regeneration has attracted significant attention. The repair of cartilage damage is challenging in orthopedics owing to its low repair capacity. Recent advances include development of injectable hydrogels to minimize invasive surgery with nanostructured features and rapid stimuli-responsive characteristics. Nanostructured SRHs with more structural similarity to natural ECM up-regulate cell-material...
Manufacturing of hydrogel biomaterials with controlled mechanical properties for tissue engineering applications
, Article Acta Biomaterialia ; Volume 62 , 2017 , Pages 42-63 ; 17427061 (ISSN) ; Minooei, F ; Mohammadi, M. H ; Khetani, S ; Rezaei Kolahchi, A ; Mashayekhan, S ; Sanati Nezhad, A ; Sharif University of Technology
Abstract
Hydrogels have been recognized as crucial biomaterials in the field of tissue engineering, regenerative medicine, and drug delivery applications due to their specific characteristics. These biomaterials benefit from retaining a large amount of water, effective mass transfer, similarity to natural tissues and the ability to form different shapes. However, having relatively poor mechanical properties is a limiting factor associated with hydrogel biomaterials. Controlling the biomechanical properties of hydrogels is of paramount importance. In this work, firstly, mechanical characteristics of hydrogels and methods employed for characterizing these properties are explored. Subsequently, the most...
Synthesis and properties of highly swelling PAAm/chitosan semi-IPN hydrogels
, Article Macromolecular Symposia ; Volume 274, Issue 1 , 2008 , Pages 171-176 ; 10221360 (ISSN) ; Pourjavadi, A ; Zohuriaan Mehr, M. J ; Sharif University of Technology
2008
Abstract
A semi-interpenetrating polymer network (semi-IPN) hydrogel composed of crosslinked chitosan and Polyacrylamide (PAAm) was prepared in the presence of formaldehyde as a crosslinker. The swelling capacity of hydrogel was shown to be affected by the crosslinker and the PAAm/chitosan ratio. The PAAm/chitosan semiIPN hydrogels are swelled at low pHs that attributed to both osmotic pressure and repulsion of -NH3+ groups on chitosan backbones. The swelling of hydrogel in acidic pHs showed that with increasing of chitosan content in the hydrogel, the swelling capacity was increased. But the swelling capacity of hydrogel in neutral pH is reversed, i.e. the higher the PAAm/chitosan ratio, the higher...
Synthesis and superswelling behavior of carboxymethylcellulose-poly(sodium acrylate-co-acrylamide) hydrogel
, Article Journal of Applied Polymer Science ; Volume 108, Issue 2 , 2008 , Pages 1142-1151 ; 00218995 (ISSN) ; Hosseinzadeh, H ; Sharif University of Technology
2008
Abstract
In this paper, attention is paid to synthesis and swelling behavior of a superabsorbent hydrogel based carboxymethylcellulose (CMC) and polyacrylonitrile (PAN). The physical mixture of CMC and PAN was hydrolyzed in NaOH solution to yield hydrogel, CMC-poly(NaAA-co-AAm). During alkaline hydrolysis, the nitrile groups of PAN were completely converted to a mixture of hydrophilic carboxamide and carboxylate groups followed by in situ crosslinking of the grafted PAN chains. A proposed mechanism for hydrogel formation was suggested and the structure of the product was established using FTIR spectroscopy. The reaction variables affecting the swelling capacity of the hydrogel were systematically...
Optimization of synthesis conditions of a novel carrageenan-based superabsorbent hydrogel by taguchi method and investigation of its metal ions adsorption
, Article Journal of Applied Polymer Science ; Volume 107, Issue 5 , 2008 , Pages 2970-2976 ; 00218995 (ISSN) ; Amini Fazl, M. S ; Barzegar, Sh ; Sharif University of Technology
2008
Abstract
The Taguchi method, a robust experimental design, was used for optimization of synthesis of a novel biopolymer-based superabsorbent hydrogel, kappa-carrageenan (K-C)-g-acrylic acid (AA)-co-2-acrylamido-2- methylpropanesulfonic acid (AMPS). The Taguchi method was applied for the experimental and standard 18 orthogonal arrays (OA) with seven factors and three levels for each factor. In the synthesis of the superabsorbent, N,N'-methylene bisacrylamide (MBA) as crosslinker, ammonium persulfate (APS) as initiator, monomer ratio (AA/AMPS), K-C concentration, Total Monomer, neutralization percent (NU), and reaction temperature were used as important factors. After analyzing with analysis of...
Grafting of acrylamide onto kappa-carrageenan via γ-irradiation: Optimization and swelling behavior
, Article Radiation Physics and Chemistry ; Volume 77, Issue 2 , 2008 , Pages 131-137 ; 0969806X (ISSN) ; Pourjavadi, A ; Sheikh, N ; Sadegh Amini Fazl, M ; Sharif University of Technology
2008
Abstract
The Taguchi method, a robust experimental design for optimization, was used for the synthesis of a superabsorbent hydrogel network using γ-rays as an initiator, energy source and crosslinker at the same time. Nine different samples of superabsorbent hydrogels were prepared in various conditions from kappa-carrageenan (κC) and acrylamide by γ-irradiation at room temperature. Considering the results of nine trials and according to analysis of variance (ANOVA), a new experimental condition with the concentrations of κC and acrylamide 1.5 g and 0.028 mol (2 g in total volume of 50 mL H2O), respectively, as well as γ-ray at the optimum total dose (7 kGy) was proposed. After preparing the desired...
Synthesis, characterization, and swelling behavior of alginate-g- poly(sodium acrylate)/kaolin superabsorbent hydrogel composites
, Article Journal of Applied Polymer Science ; Volume 105, Issue 5 , 2007 , Pages 2631-2639 ; 00218995 (ISSN) ; Ghasemzadeh, H ; Soleyman, R ; Sharif University of Technology
2007
Abstract
A novel superabsorbent composite based on sodium alginate and the inorganic clay kaolin was synthesized via the graft copolymerization of acrylic acid (AA) in an aqueous medium with methylene bisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The effects of reaction variables, such as the MBA, AA, and APS concentrations and the alginate/kaolin weight ratio, on the water absorbency of the composite were systematically optimized. Evidence of grafting and kaolin interactions was obtained by a comparison of the Fourier transform infrared spectra of the initial substrates with that of the superabsorbent composite, and the hydrogel structure was confirmed...
Optimized synthesis of carrageenan-graft-poly(sodium acrylate) superabsorbent hydrogel using the Taguchi method and investigation of its metal ion absorption
, Article Polymer International ; Volume 56, Issue 2 , 2007 , Pages 283-289 ; 09598103 (ISSN) ; Amini Fazl, M. S ; Sharif University of Technology
2007
Abstract
The Taguchi method, a robust experimental design, was used for the optimization of the synthesis of a novel biopolymer-based superabsorbent hydrogel, carrageenan-graft-poly(sodium acrylate). The Taguchi method was applied for the experiment and standard 16 orthogonal arrays with five factors and four levels for each factor were used. In the synthesis of the superabsorbent hydrogel, N,N′-methylene bisacrylamide (MBA) was used as crosslinker, ammonium persulfate as initiator, and acrylic acid as monomer. Neutralization percent and reaction temperature were used as important factors. The analysis of variance results showed that the most important factor in this synthesis was MBA concentration....