Novel Superabsorbent Hydrogel Based on Natural Hybrid Backbone: Optimized Synthesis and its Swelling Behavior

Pourjavadi, Ali,Soleyman, Rouhollah,Bardajee, Ghasem Rezanejade,Ghavami, Somayeh Korean Chemical Society 2009 Bulletin of the Korean Chemical Society Vol.30 No.11

The synthesis of a novel superabsorbent hydrogel with natural hybrid backbone via graft copolymerization of acrylamide (AAm) onto kappa-carrageenan (kC, as a polysaccharide) and gelatin (as a protein) under classic thermal conditions is described. The Taguchi method as a strong experimental design tool was used for synthesis optimization. A series of hydrogels 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 optimum hydrogel was measured in various solutions with pH values ranging from 1 to 13. In addition, swelling kinetics, swelling in various organic solvents, various salt solutions and On–Off switching behavior were investigated. The hydrogel formation was confirmed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetrical analysis (TGA). Surface morphology of the synthesized hydrogels was assessed by scanning electron microscope (SEM).

Modified Carrageenan. 6. Crosslinked Graft Copolymer of Methacrylic Acid and kappa-Carrageenan as a Novel Superabsorbent Hydrogel with Low Salt- and High pH-Sensitivity

Pourjavadi A.,Harzandi A. M.,Hosseinzadeh H. The Polymer Society of Korea 2005 Macromolecular Research Vol.13 No.6

A novel, polysaccharide-based, superabsorbent hydrogel was synthesized through crosslinking graft copolymerization of methacrylic acid (MAA) onto kappa-carrageenan ($_{k}C$), using ammonium persulfate (APS) as a free radical initiator in the presence of methylenebisacrylamide (MBA) as a crosslinker. A proposed mechanism for $_{k}C$­g-polymethacrylic acid ($_{k}C$-g-PMAA) formation was suggested and the hydrogel structure was confirmed using FTIR spectroscopy. The effect of grafting variables, including MBA, MAA, and APS concentration, was systematically optimized to achieve a hydrogel with the maximum possible swelling capacity. The swelling kinetics in distilled water and various salt solutions were preliminarily investigated. Absorbency in aqueous salt solutions of lithium chloride, sodium chloride, potassium chloride, calcium chloride, and aluminum chloride indicated that the swelling capacity decreased with increased ionic strength of the swelling medium. This behavior can be attributed to the charge screening effect for monovalent cations, as well as ionic crosslinking for multivalent cations. The swelling of super absorbing hydrogels was measured in solutions with pH ranging from 1 to 13. In addition, the pH reversibility and on-off switching behavior, at pH levels of 3.0 and 8.0, give the synthesized hydrogels great potential as an excellent candidate for the controlled delivery of bioactive agents.

Synthesis and Properties of Partially Hydrolyzed Acrylonitrile-co-Acrylamide Superabsorbent Hydrogel

Pourjavadi, Ali,Hosseinzadeh, Hossein Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.11

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 hydrogels have a porous structure. The results of Brunauer-Emmett-Teller (BET) analysis showed that the average pore diameter of the synthesized hydrogel was 13.9 nm. The synthetic parameters affecting on swelling capacity of the hydrogel, such as AM/AN weight ratio and hydrolysis time and temperature, were systematically optimized to achieve maximum swelling capacity (330 g/g). The swollen gel strength of the synthesized hydrogels was evaluated via viscoelastic measurements. The results indicated that superabsorbent polymers with high water absorbency were accompanied by low gel strength. The swelling of superabsorbent hydrogels was also measured in various solutions with pH values ranging from 1 to 13. Also, the pH reversibility and on-off switching behavior makes the hydrogel as a good candidate for controlled delivery of bioactive agents. Finally, the swelling of synthesized hydrogels with various particle sizes obey second order kinetics.

Partially Hydrolyzed Crosslinked Alginate-graft-Polymethacrylamide as a Novel Biopolymer-Based Superabsorbent Hydrogel Having pH - Responsive Properties

Pourjavadi A.,Amini-Fazi M. S.,Hosseinzadeh H. The Polymer Society of Korea 2005 Macromolecular Research Vol.13 No.1

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 and N,N'-methylenebis­acrylamide (MBA) as a crosslinker. The crosslinked graft copolymer, alginate-graft-polymethacrylamide (Alg-g­PMAM), 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 Alg-g-PMAM or the H-Alg-g-PMAM was characterized by FTIR spectroscopy. The effects of the grafting variables (i.e., concentration of MBA, MAM, and APS) and the alkaline hydrolysis conditions (i.e., NaOH concentration, hydrolysis time, and temperature) were optimized systematically to achieve a hydrogel having the maximum swelling capacity. Measurements of the absorbency in various aqueous salt solutions indicated that the swelling capacity decreased upon increasing the ionic strength of the swelling medium. This behavior could be attributed to a charge screening effect for monovalent cations, as well as ionic cross-linking for multivalent cations. Because of the high swelling capacity in salt solutions, however, the hydrogels might be considered as anti-salt superabsorbents. The swelling behavior of the superabsorbing hydrogels was also measured in solutions having values of pH ranging from 1 to 13. Furthermore, the pH reversibility and on/off switching behavior, measured at pH 2.0 and 8.0, suggested that the synthesized hydrogels were excellent candidates for the controlled delivery of bioactive agents. Finally, we performed preliminary investigations of the swelling kinetics of the synthesized hydrogels at various particle sizes.

Partially Hydrolyzed Crosslinked Alginate-graft-Polymethacrylamide as a Novel Biopolymer-Based Superabsorbent Hydrogel Having pH-Responsive Properties

A. Pourjavadi,M. S. Amini Fazl,H. Hosseinzadeh 한국고분자학회 2005 Macromolecular Research Vol.13 No.1

Novel Superabsorbent Hydrogel Based on Natural Hybrid Backbone: Optimized Synthesis and its Swelling Behavior

Ali Pourjavadi,Rouhollah Soleyman,Ghasem Rezanejade Bardajee,Somayeh Ghavami 대한화학회 2009 Bulletin of the Korean Chemical Society Vol.30 No.11

The synthesis of a novel superabsorbent hydrogel with natural hybrid backbone via graft copolymerization of acrylamide (AAm) onto kappa-carrageenan (kC, as a polysaccharide) and gelatin (as a protein) under classic thermal conditions is described. The Taguchi method as a strong experimental design tool was used for synthesis optimization. A series of hydrogels 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 optimum hydrogel was measured in various solutions with pH values ranging from 1 to 13. In addition, swelling kinetics, swelling in various organic solvents, various salt solutions and On–Off switching behavior were investigated. The hydrogel formation was confirmed by Fourier transform infrared spectroscopy (FTIR) and thermogravimetrical analysis (TGA). Surface morphology of the synthesized hydrogels was assessed by scanning electron microscope (SEM).

Functionalized mesoporous silica-coated magnetic graphene oxide by polyglycerol-g-polycaprolactone with pH-responsive behavior: Designed for targeted and controlled doxorubicin delivery

Ali Pourjavadi,Zahra Mazaheri Tehrani,Safura Jokar 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.28 No.-

In the present work a novel multifunctional drug nanocarrier was prepared. Polyglycerol-gpolycaprolactonewas grafted on Mesoporous silica-coated magnetic graphene oxide. Doxorubicin, asanticancer drug, was loaded on this carrier. The in vitro drug release showed the controlled pHresponsive behavior. At the endosomal pH (pH 5.5) the amount of drug release enhanced. Thisnanocarrier would have potential application in the tumor therapy owing to its biodegradability,controlled release and pH responsive behavior

Dendritic multi-walled carbon nanotube with thermoresponsive shells: A good carrier for anticancer drugs

Ali Pourjavadi,Zahra Mazaheri Tehrani,Tayebe Shirvani,Malihe Doulabi,Ali Bumajdad 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.35 No.-

In this research, multi-walled carbon nanotubes (MWCNTs) were modified by dendritic macromonomer. Herein, polyamidoamine with acrylamide end groups was incorporated on MWCNTs. Afterwards,poly(N-isopropylacrylamide), (PNIPAM), was grafted on polyamidoamine in a facile synthesis. Then,doxorubicin as anticancer drug was loaded on this nanocarrier. The drug release was studied at belowand above the lower critical solution temperature of PNIPAM, (LCST 32 8C), 27 8C and 37 8C, respectively. At 37 8C (body temperature) the polymer shell dehydrated and the drug release increased. The profile ofdrug release was expressed by Higuchi’s equation which indicated that the drug release mechanism wasdiffusion controlled.

Graphene oxide/poly(imidazole/imidazolium) nanocomposite: An effective support for immobilization of large amounts of Pd nanoparticles

Ali Pourjavadi,Niloofar Safaie,Seyed Hassan Hosseini,Craig Bennett 한국공업화학회 2016 Journal of Industrial and Engineering Chemistry Vol.38 No.-

A multi-layered catalyst based on poly(imidazole/imidazolium) and graphene oxide, with high loadingcapacity for immobilization of palladium nanoparticles was prepared. The catalyst was proven to behighly efficient for reduction of nitroarenes and also for Heck reaction with the use of only 0.1 mol% ofthe catalyst. The reduction of nitroarenes and Heck reaction were performed in water medium andexcellent yields of products were achieved. The synthesized catalyst was readily recovered and reusedfor up to 10 subsequent runs without significant loss of activity.

Synthesis and Properties of Partially Hydrolyzed Acrylonitrile-co -Acrylamide Superabsorbent Hydrogel

Ali Pourjavadi,Hossein Hosseinzadeh 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.11

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 hydrogels have a porous structure. The results of Brunauer-Emmett-Teller (BET) analysis showed that the average pore diameter of the synthesized hydrogel was 13.9 nm. The synthetic parameters affecting on swelling capacity of the hydrogel,such as AM/AN weight ratio and hydrolysis time and temperature, were systematically optimized to achieve maximum swelling capacity (330 g/g). The swollen gel strength of the synthesized hydrogels was evaluated via viscoelastic measurements. The results indicated that superabsorbent polymers with high water absorbency were accompanied by low gel strength. The swelling of superabsorbent hydrogels was also measured in various solutions with pH values ranging from 1 to 13. Also, the pH reversibility and on-off switching behavior makes the hydrogel as a good candidate for controlled delivery of bioactive agents. Finally, the swelling of synthesized hydrogels with various particle sizes obey second order kinetics.