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Partially hydrolyzed crosslinked alginate-graft-polymethacrylamide as a novel biopolymer-based superabsorbent hydrogel having pH-responsive Properties [electronic resource]
, Article Macromolecular Research ; January 2005, Volume 13, Issue 1, pp 45-53 ; Aminfazl, M. S ; Hosseinzadeh, H
Abstract
In this study, a series of highly swelling hydrogels based on sodium alginate (NaAlg) and polymethacrylamide (PMAM) was prepared through free radical polymerization. The graft copolymerization reaction was performed in a homogeneous medium and in the presence of ammonium persulfate (APS) as an initiator andN,N′-methylenebisacrylamide (MBA) as a crosslinker. The crosslinked graft copolymer, alginate-graft-polymethacrylamide (Alg-g-PMAM), was then partially hydrolyzed by NaOH solution to yield a hydrogel, hydrolyzed alginate-graft-polymethacrylamide (H-Alg-g-PMAM). During alkaline hydrolysis, the carboxamide groups of Alg-g-PMAM were converted into hydrophilic carboxylate anions. Either the...
Superabsorbency, pH-sensitivity and swelling kinetics of partially hydrolyzed chitosan-g-poly(acrylamide) hydrogels
, Article Turkish Journal of Chemistry ; Volume 30, Issue 5 , 2006 , Pages 595-608 ; 13000527 (ISSN) ; Mahdavinia, G.R ; Sharif University of Technology
2006
Abstract
Acrylamide (AAm) monomer was directly grafted onto chitosan using ammonium persulfate (APS) as an initiator and methylenebisacrylamide (MBA) as a crosslinking agent under an inert atmosphere. Two factors affecting the swelling capacity of the obtained hydrogel, AAm and MBA concentrations, were studied. The polymer structures were characterized by FTIR spectroscopy. Water absorbencies of the hydrogels were compared between before and after the alkaline hydrolysis treatment. Saponification of chitosan-g-poly(acrylamide) (chitosan-g-PAAm) with a hot sodium hydroxide solution gave rise to a high water absorbency. Swelling of the hydrogel samples in saline solution (0.15 mol/L NaCl, CaCl2 and...
Synthesis and swelling behavior of a novel protein-based superabsorbent hydrogel composite: Collagen-g-poly (sodium acrylate)/kaolin
, Article Journal of Polymer Materials ; Volume 23, Issue 3 , 2006 , Pages 331-339 ; 09738622 (ISSN) ; Feizabadi, Kh ; Hosseinzadeh, H ; Sharif University of Technology
2006
Abstract
This article describes the synthesis and swelling properties of a superabsorbing hydrogel composite based on collagen. The composite have been prepared via graft copolymerization of acrylic acid (AA) in the presence of kaolin powder using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The certain variables of the graft copolymerization (i.e. the monomer, the initiator, and the crosslinker concentration as well as kaolin/collagen weight ratio) affected on the ultimate water-swelling capacity were optimized. Evidence of grafting and kaolin interaction was obtained by comparison of FTIR spectra of initial substrates and superabsorbent...
Superabsorbent hydrogels from starch-g-PAN: Effect of some reaction variables on swelling behavior
, Article Journal of Polymer Materials ; Volume 20, Issue 1 , 2003 , Pages 113-120 ; 09700838 (ISSN) ; Pourjavadi, A ; Sharif University of Technology
2003
Abstract
Two series of alkali hydrolyzed starch-g-polyacrylonitrile (H-SPAN) superabsorbents were prepared from granular and gelatinized corn starches. The grafting parameters of SPAN copolymers were determined and the polymers were analyzed by FTIR spectroscopy. A combination of three influencing factors (i.e. thermal pre-treatment of the initial starch, presence or absence of oxygen in the stage of ceric-initiated PAN grafting, and neutralization after alkali treatment) on swelling characteristics of the final hydrogel was evaluated in a practical viewpoint. The superabsorbents were discriminated according to their swelling behavior in water and different aqueous salt solutions. The swelling...
Constitutive Modeling for Transient Swelling Behavior of Polymeric Hydrogel with Large Deformations
, Ph.D. Dissertation Sharif University of Technology ; Naghdabadi, Reza (Supervisor) ; Sohrabpour, Saeed (Supervisor) ; Baghani, Mostafa (Co-Advisor)
Abstract
In this work, the mechanical behavior of smart hydrogels is studied for temperature sensitive and, pH and temperature sensitive ones. First, an equilibrium model is presented for the temperature sensitive hydrogles which is continuous and numerically stable especially in the vicinity of the phase transition temperature. The model results are validated through comparing them with the experimental data available in the literature. The model results are in good agreement with those of experiments especially for hydrogels with high cross-linking density. Then, the model is implemented in a finite element framework by which some homogeneous and inhomogeneous problems are numerically solved....
Synthesis of Organic Solvent Absorbent Crosslinked Polymers Based on Carbon Nanotubes and Hydrophobic Monomer
, Ph.D. Dissertation Sharif University of Technology ; Pourjavadi, Ali (Supervisor)
Abstract
In this thesis, organic solvent absorbent crosslinked polymers based on carbon nanotubes and hydrophobic monomers were synthesized by radical polymerization. Surfaces of carbon nanotubes were modified for the better dispersion in a polymeric matrix and participation in polymeric reactions. Different hydrophobic monomers such as diphenyl acrylamide and ionic liquids based on vinyl imidazolium cation with long alkyl chain and lipophilic counter anion such as tetrafluoro borate were synthesized and utilized with hydrophobic long alkyl chain acrylate monomers for the preparation of organogels. Swelling behavior of synthesized organogels in different organic solvents was investigated. The results...
Analysis of Photo-Mechanical Response of Light Sensitive Homogeneous Hydrogels
, M.Sc. Thesis Sharif University of Technology ; Naghdabadi, Reza (Supervisor)
Abstract
Light-sensitive hydrogels are advanced materials with modern applications that have the ability to deform with light radiation at specific frequencies. Numerous studies have been conducted to identify the behavior and deformation of these materials. Most studies have experimentally investigated the light-sensitive behavior of hydrogels. On the other hand, modeling the behavior of light-sensitive hydrogels is very complicated, so that the use of these models is possible only in certain cases. Therefore, in the present study, the existing studies have been reviewed in order to simplify the relationships governing the deformation of light-sensitive hydrogels. In this regard, the deformation...
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....
Multiwalled carbon nanotube-polyelectrolyte gels: Preparation and swelling behavior for organic solvents
, Article Solid State Ionics ; Vol. 257 , 2014 , pp. 32-37 ; ISSN: 01672738 ; Doulabi, M ; Sharif University of Technology
Abstract
In this article, we report the first multiwalled carbon nanotube-polyelectrolyte gel containing vinylimidazolium-typed ionic liquid monomer as an absorbent of less-polar or nonpolar organic solvents. To prepare such MWCNT-polyelectrolyte gel, the modified MWCNTs with polymerizable vinyl groups on their surfaces were prepared and then underwent copolymerizations with dodecyl methacrylate and vinylimidazolium in the presence of AIBN as initiator, yielding a cross-linked polyelectrolyte. In order to estimate the compatibility between the solvents and the polymers, a series of vinylimidazolium-typed ionic liquid monomers ([Cnvim][X]) with different alkyl tail length (C6, C10 and C12) and counter...
Novel highly swelling nanoporous hydrogel based on polysaccharide/protein hybrid backbone
, Article Journal of Polymer Research ; Volume 18, Issue 3 , 2011 , Pages 337-346 ; 10229760 (ISSN) ; Pourjavadi, A ; Soleyman, R ; Sharif Unviersity of Technology
2011
Abstract
Novel high capacity swelling nanoporous hydrogel (NPH) was synthesized via graft copolymerization of acrylamide (AAm) onto kappa-carrageenan (kC, as a polysaccharide) and gelatin (as a protein) hybrid backbone, after hydrolysis of this system. The Taguchi method as a strong experimental design tool was used for its optimized synthesis. The Taguchi method was applied for the experimental and standard 9 orthogonal array (OA) with four factors and three levels for each factor. A series of NPHs were synthesized by proposed conditions of Qualitek-4 Software. Considering the results of 9 trials according to analysis of variance (ANOVA), optimum conditions were proposed. The swelling behavior of...
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...
Coupling behavior of the pH/temperature sensitive hydrogels for the inhomogeneous and homogeneous swelling
, Article Smart Materials and Structures ; Volume 25, Issue 8 , 2016 ; 09641726 (ISSN) ; Baghani, M ; Naghdabadi, R ; Sohrabpour, S ; Sharif University of Technology
Institute of Physics Publishing
2016
Abstract
In this work, a model is developed to continuously predict homogeneous and inhomogeneous swelling behavior of pH/temperature sensitive PNIPAM hydrogels. Employing the model, homogeneous swelling of the pH/temperature sensitive hydrogel is investigated for free and biaxial constrained swelling cases. Comparing the model results with the experimental data available in the literature, the validity of the model is confirmed. The model is then employed to investigate inhomogeneous swelling of a spherical shell on a hard core both analytically and numerically for pH or temperature variations. In this regard, numerical tools are developed via preparing a user defined subroutine in ABAQUS software....
Experimental investigation on CO2-light crude oil interfacial and swelling behavior
, Article Chinese Journal of Chemical Engineering ; 2017 ; 10049541 (ISSN) ; Ayatollahi, S ; Sharif University of Technology
Abstract
A systematic series of experiments are designed and performed including interfacial tension (IFT) measurements concomitant with Bond (BN, the ratio of gravity forces to capillary forces) and swelling/extraction measurements. Dynamic IFT, BN and swelling/extraction are measured as a function of pressure at temperatures of 30, 50 and 80°C. In addition, in the light of measured IFT the minimum miscibility pressure (MMP) of CO2 and light crude oil is determined based on a method called vanishing interfacial tension (VIT). The obtained results interestingly revealed that equilibrium IFT decreases linearly with pressure in two distinct pressure intervals while equilibrium BN shows an increasing...
Improving survivability of lactobacillus plantarum in alginate-chitosan beads reinforced by Na-tripolyphosphate dual cross-linking
, Article LWT ; Volume 97 , 2018 , Pages 440-447 ; 00236438 (ISSN) ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
Abstract
In the present study, Lactobacillus plantarum PTCC 1058 was microencapsulated in Alginate-chitosan blended beads based on ionically dual cross-linking by Na-tripolyphosphate (Na-TPP). The homogenous solution of bacteria and alginate was dripped into the gelling bath of calcium chloride. After 30 min hardening, filtrate beads were transferred into the solution of chitosan. Dual cross-linked gel beads were prepared by employing Na-TPP solution to the chitosan coated beads. Morphology, particle size, alginate-chitosan interaction, characterizing the structure of single and dual cross-linked beads were determined by using scanning electron microscopy SEM, FTIR and XRD analysis. FTIR analysis...
Experimental investigation on CO2-light crude oil interfacial and swelling behavior
, Article Chinese Journal of Chemical Engineering ; Volume 26, Issue 2 , 2018 , Pages 373-379 ; 10049541 (ISSN) ; Ayatollahi, S ; Sharif University of Technology
Chemical Industry Press
2018
Abstract
A systematic series of experiments are designed and performed including interfacial tension (IFT) measurements concomitant with Bond (BN, the ratio of gravity forces to capillary forces) and swelling/extraction measurements. Dynamic IFT, BN and swelling/extraction are measured as a function of pressure at temperatures of 30, 50 and 80 °C. In addition, in the light of measured IFT the minimum miscibility pressure (MMP) of CO2 and light crude oil is determined based on a method called vanishing interfacial tension (VIT). The obtained results interestingly revealed that equilibrium IFT decreases linearly with pressure in two distinct pressure intervals while equilibrium BN shows an increasing...
Synthesis and investigation of swelling behavior of new agar based superabsorbent hydrogel as a candidate for agrochemical delivery
, Article Journal of Polymer Research ; Volume 16, Issue 6 , 2009 , Pages 655-665 ; 10229760 (ISSN) ; Farhadpour, B ; Seidi, F ; Sharif University of Technology
2009
Abstract
In this investigation a new type of superabsorbent hydrogel based on agar was prepared, and the effect of the feed ratio of some components (acrylic acid, MBA, APS and agar) on the swelling capacity of the hydrogel was systematically studied. Maximum water absorbency of the optimized final product was found to be 1,100∈g/g in distilled water. The structure of the hydrogel was characterized by FT-IR method and morphology of the samples was examined by scanning electron microscopy (SEM). Swelling properties of optimized hydrogel sample in different swelling mediums were investigated. The optimum hydrogel were also loaded with potassium nitrate and its potential for controlled release of...
Swelling behavior of heavy crude oil during injection of carbonated brine containing chloride anion
, Article Journal of Molecular Liquids ; Volume 276 , 2019 , Pages 7-14 ; 01677322 (ISSN) ; Zeinolabedini Hezave, A ; Ayatollahi, S ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Carbonated brine (CB) injection, known as one of the effective enhanced oil recovery processes, is highly dependent on the reservoir conditions (i.e. temperature and pressure) as well as the type of dissolved salt in aqueous solution. This study is aimed to investigate the influential parameters on the swelling of crude oil as the most important mechanism during CB injection. The swelling of crude oil in the presence of different CB solutions consisted of different salts such as KCl, NaCl, CaCl2 and MgCl2 with constant concentration of 15,000 ppm is studied using a high-pressure, high-temperature visual cell which measures the volume of drop using image processing software based on...
Grafted CMC/silica gel superabsorbent composite: Synthesis and investigation of swelling behavior in various media
, Article Journal of Applied Polymer Science ; Volume 108, Issue 5 , 2008 , Pages 3281-3290 ; 00218995 (ISSN) ; Seidi, F ; Salimi, H ; Soleyman, R ; Sharif University of Technology
2008
Abstract
In the present study, we attempt to synthesize and characterize novel CMC-g-poly (acrylic acid-co-2-acrylamido-2-methylpropanesulfonic acid)/silica gel composite. Infrared spectroscopy and TGA thermal analysis were carried out to confirm the chemical structure of the hydrogel. Moreover, morphology of the samples was examined by scanning electron microscopy. The effect of reaction variables affecting on water absorbency of the composite and swelling behavior in various solvents, salt, and pH solutions was investigated. Maximum water absorbency of the optimized final product was found to be 4000 g/g in distilled water. The absorbency under load (AUL) of the hydrogel was also determined by...
Interactions between superabsorbent polymers and cement-based composites incorporating colloidal silica nanoparticles
, Article Cement and Concrete Composites ; Volume 37, Issue 1 , March , 2013 , Pages 196-204 ; 09589465 (ISSN) ; Fakoorpoor, S. M ; Hosseini, P ; Khaloo, A ; Sharif University of Technology
2013
Abstract
The relatively new applications of superabsorbent polymers (SAPs) in cement based materials call for investigations regarding their behaviors in relation to other constituents in the system. Colloidal silica nanoparticles (CS) are becoming increasingly important for the improvement of strength and durability of cement based materials. In this study, a poly (AA-co-AM) SAP was synthesized by free radical polymerization, and its behaviors in cement based composites incorporating CS were investigated. These included swelling behavior, setting time, mechanical performance in different curing conditions, and rheological properties of fresh pastes. The observation of an unusual reduction in...
Salep-g-poly(sodium acrylate)/alumina as an environmental-sensitive biopolymer superabsorbent composite: Synthesis and investigation of its swelling behavior
, Article Advances in Polymer Technology ; Volume 31, Issue 1 , 2012 , Pages 41-51 ; 07306679 (ISSN) ; Pourjavadi, A ; Soleyman, R ; Ghavami, S ; Sharif University of Technology
Abstract
A novel kind of a biopolymer-based superabsorbent composite, salep-g-poly(sodium acrylate)/alumina, was prepared from salep, sodium acrylate, and alumina by aqueous polymerization, using N,N'-methylenebisacrylamide (MBA) as a cross-linker and ammonium persulfate (APS) as an initiator. The reaction parameters [i.e., acrylic acid (AA), MBA, APS amounts, and neutralization percentage of AA as well as alumina/salep weight ratio] affecting the water absorbency of the hydrogel composite were optimized using systematic method to achieve a composite with high swelling capacity as possible. The swelling behavior of optimum superabsorbent composite was measured in various pH solutions. In addition,...