Iranian Journal of Polymer Science and Technology 10163255 37 4 2024 10 22 Synthesis and Characterization of a Composite Hydrogel Based on Carboxymethyl Cellulose and ß-Cyclodextrin, Modified with Adipic Acid: Investigating Its Absorption Behavior In Different Saline and Acidic Environments Synthesis and Characterization of a Composite Hydrogel Based on Carboxymethyl Cellulose and ß-Cyclodextrin, Modified with Adipic Acid: Investigating Its Absorption Behavior In Different Saline and Acidic Environments 2086 10.22063/jipst.2025.3708.2343 FA Fateme Yazdaninejad Department of Soil Science, College of Agriculture, Shahid Chamran University of Ahvaz, Postal Code: 61357-83151, Ahvaz , Iran Mostafa Chorom Department of Soil Science, College of Agriculture, Shahid Chamran University of Ahvaz, Postal Code: 61357-83151, Ahvaz , Iran Mohammad Javaherian Department of Chemistry, College of Science, Shahid Chamran University of Ahvaz,Postal Code: 61357-83151, Ahvaz , Iran Journal Article 2024 08 06 Hypothesis: New methods of fertilizer application in agriculture can increase the efficiency of irrigation and improve the exploitation of water and soil resources. Using controlled release systems based on superabsorbent polymers (hydrogels) is one of the appropriate solutions to reduce the wastage of water and nutrients. Hydrogels are able to absorb water from irrigation and rainfall, prevent its deep subsidence and increase the efficiency of water consumption Methods: In this study, the biodegradable compounds of carboxymethyl cellulose ß-yclodextrin and crosslinker adipic acid were used to make hydrogel. The synthesized hydrogel was investigated in terms of swelling capacity in distilled water, NaCl and CaCl2 salt solutions and pH changes Findings: The water absorption process reached the maximum value (78 g/g) within 60 min and then remained almost constant. The highest amount of water absorption was obtained in a solution with pH 7 (1350 g/g). By increasing the concentration of sodium chloride salt solutions from 0.1 M to 0.3 M, the amount of swelling decreased from 48 g/g to 30 g/g and in calcium chloride salt from 21 g/g to 4 g/g, respectivelyThe information obtained from FTIR spectroscopy showed that the produced hydrogel has high porosity and a suitable equilibrium swelling ratio. The morphology of the synthesized hydrogel with TEM and SEM images showed that the synthesized hydrogel has a network structure and a completely porous surface, which increases the absorption of water and nutrients. The thermal stability evaluation (TGA) also showed that the synthesized hydrogel was resistant up to a temperature of 80°C, and with the increase in temperature to 650°C, the weight of the tested sample changed by 62.34%, and from 650°C onwards, the weight of the sample remained constant. This increase in degradation temperature and constant weight of the hydrogel sample indicates an increase in the strength of the bonds in the synthesized hydrogel Hypothesis: New methods of fertilizer application in agriculture can increase the efficiency of irrigation and improve the exploitation of water and soil resources. Using controlled release systems based on superabsorbent polymers (hydrogels) is one of the appropriate solutions to reduce the wastage of water and nutrients. Hydrogels are able to absorb water from irrigation and rainfall, prevent its deep subsidence and increase the efficiency of water consumption Methods: In this study, the biodegradable compounds of carboxymethyl cellulose ß-yclodextrin and crosslinker adipic acid were used to make hydrogel. The synthesized hydrogel was investigated in terms of swelling capacity in distilled water, NaCl and CaCl2 salt solutions and pH changes Findings: The water absorption process reached the maximum value (78 g/g) within 60 min and then remained almost constant. The highest amount of water absorption was obtained in a solution with pH 7 (1350 g/g). By increasing the concentration of sodium chloride salt solutions from 0.1 M to 0.3 M, the amount of swelling decreased from 48 g/g to 30 g/g and in calcium chloride salt from 21 g/g to 4 g/g, respectivelyThe information obtained from FTIR spectroscopy showed that the produced hydrogel has high porosity and a suitable equilibrium swelling ratio. The morphology of the synthesized hydrogel with TEM and SEM images showed that the synthesized hydrogel has a network structure and a completely porous surface, which increases the absorption of water and nutrients. The thermal stability evaluation (TGA) also showed that the synthesized hydrogel was resistant up to a temperature of 80°C, and with the increase in temperature to 650°C, the weight of the tested sample changed by 62.34%, and from 650°C onwards, the weight of the sample remained constant. This increase in degradation temperature and constant weight of the hydrogel sample indicates an increase in the strength of the bonds in the synthesized hydrogel

http://jips.ippi.ac.ir/article_2086_7768607fd348244c0e23914f5e56e393.pdf

Iranian Journal of Polymer Science and Technology 10163255 37 4 2024 10 22 Design and Fabrication of Porous Silicon-Gelatin Hybrid to Detect Bacterial Growth by Reflectometric Interference Fourier Transform Spectrometry Design and Fabrication of Porous Silicon-Gelatin Hybrid to Detect Bacterial Growth by Reflectometric Interference Fourier Transform Spectrometry 2094 10.22063/jipst.2025.35553.2346 FA Shima Abarghoe Department of Nanobiotechnology and Biomimetic, Faculty of Biological Sciences Engineering, Faculty of Interdisciplinary Sciences and Technologies, University of Tehran, Tehran, Iran Fereshteh Rahimi Department of Nanobiotechnology and Biomimetic, Faculty of Life Sciences Engineering, Faculty of Interdisciplinary Sciences and Technologies, University of Tehran, Tehran, Iran 0000-0003-0020-644X Nizami Duran Department of Microbiology, Faculty of Medicine, Mustafa Kemal Hatay University, Antakya-Hatay, Turkiye Ali Abouei Mehrizi Department of Medical Technology and Tissue Engineering, Faculty of Life Sciences Engineering, Faculty of Interdisciplinary Sciences and Technologies, University of Tehran, Tehran, Iran Mahsa Sedighi Department of Pharmaceutics and Nanotechnology, Faculty of Pharmacy, Birjand University of Medical Sciences, Birjand, Iran Journal Article 2024 09 23 Hypothesis: The detection of pathogenic bacteria in food and clinical samples is valuable, and diagnosing them in a short period of time remains a challenge. In this research, an optical nanosensor based on Fourier transform spectroscopy from a porous silicon integrated with gelatin hydrogel was used to detect bacterial growth. Gelatin is a pH-sensitive hydrogel that swells quickly with the growth of bacteria and changes in the pH of the environment. The hybrid of this hydrogel with porous silicon nanostructure creates a pH-sensitive structure whose refractive index changes with bacterial growth and pH changes. This change causes a variation in the effective optical thickness of the hybrid nanostructure, which can be investigated using Fourier transform spectrometry Methods: First, electrochemical etching was used to fabricate porous silicon. In the next step, the oxidized porous silicon surface was functionalized with APTES, which leaves amine groups on the surface for conjugation with gelatin .Finally, the swelling behavior of hydrogel in hybrid was investigated in response to environmental pH changes and then in the presence of different concentrations of bacteria Findings: By X-ray energy dispersive spectroscopy in mapping mode and checking the distribution of elements, the penetration of the gel into the pores of porous silicon was observed. By analyzing the Fourier transform spectrometry of the porous siliconegelatin hybrid in the presence of buffers with different pH levels, it was determined that due to the swelling of the gel layer and the refractive index of this layer approaching the refractive index of the surrounding environment, the location of the first peak used as the fluid peak can be considered as a diagnostic point. The results showed that this structure has the ability to detect changes in environmental pH as well as bacterial growth in the concentration range of 102 to 105 cfu/mL. Hypothesis: The detection of pathogenic bacteria in food and clinical samples is valuable, and diagnosing them in a short period of time remains a challenge. In this research, an optical nanosensor based on Fourier transform spectroscopy from a porous silicon integrated with gelatin hydrogel was used to detect bacterial growth. Gelatin is a pH-sensitive hydrogel that swells quickly with the growth of bacteria and changes in the pH of the environment. The hybrid of this hydrogel with porous silicon nanostructure creates a pH-sensitive structure whose refractive index changes with bacterial growth and pH changes. This change causes a variation in the effective optical thickness of the hybrid nanostructure, which can be investigated using Fourier transform spectrometry Methods: First, electrochemical etching was used to fabricate porous silicon. In the next step, the oxidized porous silicon surface was functionalized with APTES, which leaves amine groups on the surface for conjugation with gelatin .Finally, the swelling behavior of hydrogel in hybrid was investigated in response to environmental pH changes and then in the presence of different concentrations of bacteria Findings: By X-ray energy dispersive spectroscopy in mapping mode and checking the distribution of elements, the penetration of the gel into the pores of porous silicon was observed. By analyzing the Fourier transform spectrometry of the porous siliconegelatin hybrid in the presence of buffers with different pH levels, it was determined that due to the swelling of the gel layer and the refractive index of this layer approaching the refractive index of the surrounding environment, the location of the first peak used as the fluid peak can be considered as a diagnostic point. The results showed that this structure has the ability to detect changes in environmental pH as well as bacterial growth in the concentration range of 102 to 105 cfu/mL.

http://jips.ippi.ac.ir/article_2094_53268583d58c5d91a18792c29a6b5eeb.pdf

Iranian Journal of Polymer Science and Technology 10163255 37 4 2024 10 22 Investigating the Effect of Hydrophobic Nanoparticles on the Performance of Poly(vinyl chloride) Hollow Fiber Membrane Contactors for Carbon Dioxide Absorption Investigating the Effect of Hydrophobic Nanoparticles on the Performance of Poly(vinyl chloride) Hollow Fiber Membrane Contactors for Carbon Dioxide Absorption 2087 10.22063/jipst.2025.35563.2348 FA Parya Amirabedi Department Chemical Engineering, Behbahan Khatam Alanbia University of Technology, Postal Code: 65716-63963,Behbahan, Iran Mahdi Elyasi Kojabad Department Chemical Engineering, Behbahan Khatam Alanbia University of Technology, Postal Code: 65716-63963,Behbahan, Iran Saba Raveshiyan Department of Chemistry Engineering, Tarbiat Modares University, P.O. Box:14115-111, Tehran, Iran Masoud Dorfeshan Department Mechanical Engineering, Behbahan Khatam Alanbia University of Technology, Postal Code: 65716-63963, Behbahan, Iran Journal Article 2024 10 08 Hypothesis: Membrane contactors are one of the new and effective technologies to reduce the pollution resulting from the emission of carbon dioxide gas (CO2) in the environment. These equipments are considered a good alternative to traditional gas absorption methods due to their many advantages. However, despite having important advantages, the wetting of polymer membranes due to contact with liquid absorbents and especially amine solutions is one of the main disadvantages of this equipment Methods: In order to reduce the wetting problem of membranes, in the present study, pure poly(vinyl chloride) (PVC) membranes and mixed matrix membranes containing calcium carbonate nanoparticles and silica nanoparticles, grafted with methyl agent were fabricated by non-solvent induce phase separation method for use in the CO2 absorption process. In the meantime, the structure and performance of the membranes were investigated using different tests. Findings: The results showed that the size of the pores increased with the increase in the percentage of nanoparticles in the polymer solution. So that, the membranes containing 2% (by wt) of nanoparticles had larger finger like pores than other membranes. Also despite the increase in the size of the finger like pores, the presence of nanoparticles in the structure of the mixed matrix membranes caused a noticeable improvement in the tensile strength of these membranes compared to the pure PVC membrane. In addition, the contact angle test showed that the mixed matrix membranes have a larger contact angle than the pure PVC membrane. Thus, the membrane containing 1.5% by wt) of CaCO3 nanoparticles and the membrane containing 2% (by wt) of silica nanoparticles grafted with methyl agent had the highest contact angle. In addition the CO2 absorption test indicated that at an absorbent velocity of 250 m/s, the PVC CO3 mixed matrix membrane exhibited the highest CO2 absorption flux, which was 1.45 × 10-3 mol/m2s. Hypothesis: Membrane contactors are one of the new and effective technologies to reduce the pollution resulting from the emission of carbon dioxide gas (CO2) in the environment. These equipments are considered a good alternative to traditional gas absorption methods due to their many advantages. However, despite having important advantages, the wetting of polymer membranes due to contact with liquid absorbents and especially amine solutions is one of the main disadvantages of this equipment Methods: In order to reduce the wetting problem of membranes, in the present study, pure poly(vinyl chloride) (PVC) membranes and mixed matrix membranes containing calcium carbonate nanoparticles and silica nanoparticles, grafted with methyl agent were fabricated by non-solvent induce phase separation method for use in the CO2 absorption process. In the meantime, the structure and performance of the membranes were investigated using different tests. Findings: The results showed that the size of the pores increased with the increase in the percentage of nanoparticles in the polymer solution. So that, the membranes containing 2% (by wt) of nanoparticles had larger finger like pores than other membranes. Also despite the increase in the size of the finger like pores, the presence of nanoparticles in the structure of the mixed matrix membranes caused a noticeable improvement in the tensile strength of these membranes compared to the pure PVC membrane. In addition, the contact angle test showed that the mixed matrix membranes have a larger contact angle than the pure PVC membrane. Thus, the membrane containing 1.5% by wt) of CaCO3 nanoparticles and the membrane containing 2% (by wt) of silica nanoparticles grafted with methyl agent had the highest contact angle. In addition the CO2 absorption test indicated that at an absorbent velocity of 250 m/s, the PVC CO3 mixed matrix membrane exhibited the highest CO2 absorption flux, which was 1.45 × 10-3 mol/m2s.

http://jips.ippi.ac.ir/article_2087_aa4f4b0905f57c84668051e7ef31a6cc.pdf

Iranian Journal of Polymer Science and Technology 10163255 37 4 2024 10 22 Synthesis and Investigating the Properties of a New Generation of High Modulus Epoxy Glycidyl Ester Resins with Epoxidized Aliphatic Ring Synthesis and Investigating the Properties of a New Generation of High Modulus Epoxy Glycidyl Ester Resins with Epoxidized Aliphatic Ring 2091 10.22063/jipst.2025.35601.2356 FA Mahsa Ghasri Department of Polymer Engineering, Faculty of Materials and Manufacturing Technologies, Malek-Ashtar University of Technology, P.O. Box: 15875-1774,Tehran, Iran 0009-0000-0114-6392 Mehrzad Mortezaei Department of Polymer Engineering, Faculty of Materials and Manufacturing Technologies, Malek-Ashtar University of Technology, P.O. Box: 15875-1774,Tehran, Iran 0000-0003-4045-1810 Hassan Fattahi Department of Polymer Engineering, Faculty of Materials and Manufacturing Technologies, Malek-Ashtar University of Technology, P.O. Box: 15875-1774,Tehran, Iran 0000-0002-0436-5088 Maryam Tavakolizadeh Department of Chemistry, Sharif University of Technology, Postal Code: 14588-9694, Tehran, Iran 0000-0003-1016-604X Journal Article 2024 11 26 Hypothesis: Considering the properties and many applications of epoxy resins in the industry, cycloaliphatic structure in these resins can improve the chemical physical, mechanical and electrical properties of epoxy systems. The aim of this research is the synthesis of cycloaliphatic epoxy resins of bi-functional diglycidyl 4-cyclohexane-1,2-dicarboxylate (Cyclo-2F) and tri-functional diglycidyl-4,5-epoxycyclohexane 1,2 dicarboxylate (Cyclo-3F) and studying the effect of a number of epoxy functional groups and the type of placement of the cycloaliphatic ring on the final properties Methods: To achieve this goal, tetrahydrophthalic anhydride was used as the raw material and the synthesis was done with epichlorohydrin and TCCA. In this researchtwo epoxy resins (bi-functional and tri-functional) have been synthesized, also, the effect of adding NaOH as a solid or solution to the reaction medium to close the epoxy ring was investigated. The synthesis steps were investigated and confirmed using FTIR, 1H-NMR and epoxy equivalent weight (EEW) analyses. To check the final properties, the synthesized resins were cured with m-phenylenediamine (m-PDA) and analyzed by TGA, DSC, tensile and DMTA analysis. Findings: Due to the presence of ester groups in the main structure, the Cyclo-2Fepoxy resin has relatively good modulus and strength, but because the cycloaliphatic structure is not placed in the cured network by hanging out, it practically does not contribute much to the process of transferring stress and improving properties. While in the Cyclo-3F resin, the presence of the epoxy group on the aliphatic ring causes this structure to be placed in the cured network, and in addition to increasing the density of crosslinks, it can withstand the introduced stress and external energies into the composite. If the synthesized tri-functional cycloaliphatic epoxy resin is cured with m-phenylenediamine, it has a tensile modulus of 5.3 GPa, which has improved by more than 50% compared to conventional bisphenol epoxy resins. Hypothesis: Considering the properties and many applications of epoxy resins in the industry, cycloaliphatic structure in these resins can improve the chemical physical, mechanical and electrical properties of epoxy systems. The aim of this research is the synthesis of cycloaliphatic epoxy resins of bi-functional diglycidyl 4-cyclohexane-1,2-dicarboxylate (Cyclo-2F) and tri-functional diglycidyl-4,5-epoxycyclohexane 1,2 dicarboxylate (Cyclo-3F) and studying the effect of a number of epoxy functional groups and the type of placement of the cycloaliphatic ring on the final properties Methods: To achieve this goal, tetrahydrophthalic anhydride was used as the raw material and the synthesis was done with epichlorohydrin and TCCA. In this researchtwo epoxy resins (bi-functional and tri-functional) have been synthesized, also, the effect of adding NaOH as a solid or solution to the reaction medium to close the epoxy ring was investigated. The synthesis steps were investigated and confirmed using FTIR, 1H-NMR and epoxy equivalent weight (EEW) analyses. To check the final properties, the synthesized resins were cured with m-phenylenediamine (m-PDA) and analyzed by TGA, DSC, tensile and DMTA analysis. Findings: Due to the presence of ester groups in the main structure, the Cyclo-2Fepoxy resin has relatively good modulus and strength, but because the cycloaliphatic structure is not placed in the cured network by hanging out, it practically does not contribute much to the process of transferring stress and improving properties. While in the Cyclo-3F resin, the presence of the epoxy group on the aliphatic ring causes this structure to be placed in the cured network, and in addition to increasing the density of crosslinks, it can withstand the introduced stress and external energies into the composite. If the synthesized tri-functional cycloaliphatic epoxy resin is cured with m-phenylenediamine, it has a tensile modulus of 5.3 GPa, which has improved by more than 50% compared to conventional bisphenol epoxy resins.

http://jips.ippi.ac.ir/article_2091_b341ea4d4ed8c5924b05ca1279e72b76.pdf

Iranian Journal of Polymer Science and Technology 10163255 37 4 2024 10 22 Signal-to-Noise Ratio Analysis for Evaluating and Optimizing the Impact Strength of Polyamide/Carbon Fiber Polymeric Composites in 3D Printing Process Signal-to-Noise Ratio Analysis for Evaluating and Optimizing the Impact Strength of Polyamide/Carbon Fiber Polymeric Composites in 3D Printing Process 2090 10.22063/jipst.2025.35624.2363 FA Rezgar Hasanzadeh Department of Mechanical Engineering, Kermanshah University of Technology, Postal Cod: 671568542, Kermanshah, Iran 0000-0002-1982-438X Journal Article 2024 12 21 Hypothesis: Precise control of 3D printing process parameters helps improve the final quality of parts and reduce the likelihood of production defects. Therefore, using the signal-to-noise analysis of Taguchi method can be employed for controlling and optimizing the process conditions of 3D printing of polyamide/carbon fiber polymer composites to improve impact strength. Methods: In this study, polymeric composite samples of polyamide/carbon fiber were fabricated using the fused filament fabrication (FFF) 3D printing process. Three processing parameters-printing temperature, printing speed, and layer height-were considered as the main variables, and their effects on the impact strength of the samples were investigated and optimized using the Taguchi method's signal-to-noise ratio analysis. Findings: The results indicated that higher printing temperatures improved the adhesion between layers and increased the impact strength. By increasing the printing temperature from 220 ℃ to 240 ℃, the impact strength increased from 52.91 kJ/m2 to 107.19 kJ/m2, representing a 103% improvement in impact strength. By increasing the printing speed from 20 mm/s to 30 mm/s, the impact strength increased from 68.15 kJ/m2 to 88.56 kJ/m2, representing a 30% improvement. Finally, increasing the layer height up to a certain value led to a decrease in impact strength, followed by a subsequent increase. A layer height of 0.1 mm resulted in the highest impact strength of 94.92 kJ/m2. By analyzing the results and using the Taguchi method, the optimal conditions for achieving maximum impact strength were identified as a printing temperature of 240 ℃, a printing speed of 30 mm/s, and a layer height of 0.1 mm. Under these optimal conditions, the impact strength of the polyamide/carbon fiber polymer composite samples was 108.15 kJ/m2. This study provides effective optimization strategies to enhance 3D printing processes and develop advanced composite materials for industrial applications. Hypothesis: Precise control of 3D printing process parameters helps improve the final quality of parts and reduce the likelihood of production defects. Therefore, using the signal-to-noise analysis of Taguchi method can be employed for controlling and optimizing the process conditions of 3D printing of polyamide/carbon fiber polymer composites to improve impact strength. Methods: In this study, polymeric composite samples of polyamide/carbon fiber were fabricated using the fused filament fabrication (FFF) 3D printing process. Three processing parameters-printing temperature, printing speed, and layer height-were considered as the main variables, and their effects on the impact strength of the samples were investigated and optimized using the Taguchi method's signal-to-noise ratio analysis. Findings: The results indicated that higher printing temperatures improved the adhesion between layers and increased the impact strength. By increasing the printing temperature from 220 ℃ to 240 ℃, the impact strength increased from 52.91 kJ/m2 to 107.19 kJ/m2, representing a 103% improvement in impact strength. By increasing the printing speed from 20 mm/s to 30 mm/s, the impact strength increased from 68.15 kJ/m2 to 88.56 kJ/m2, representing a 30% improvement. Finally, increasing the layer height up to a certain value led to a decrease in impact strength, followed by a subsequent increase. A layer height of 0.1 mm resulted in the highest impact strength of 94.92 kJ/m2. By analyzing the results and using the Taguchi method, the optimal conditions for achieving maximum impact strength were identified as a printing temperature of 240 ℃, a printing speed of 30 mm/s, and a layer height of 0.1 mm. Under these optimal conditions, the impact strength of the polyamide/carbon fiber polymer composite samples was 108.15 kJ/m2. This study provides effective optimization strategies to enhance 3D printing processes and develop advanced composite materials for industrial applications.

http://jips.ippi.ac.ir/article_2090_2194f5c52e275db194c2d07631df534a.pdf

Iranian Journal of Polymer Science and Technology 10163255 37 4 2024 10 22 Synthesis and Characterization of Self-Healing, Dual-Network Hydrogels Based on Polyvinyl alcohol: StructureProperty Relationships in a Viscoelastic System Synthesis and Characterization of Self-Healing, Dual-Network Hydrogels Based on Polyvinyl alcohol: StructureProperty Relationships in a Viscoelastic System 2093 10.22063/jipst.2025.35633.2368 FA Homa Etemadi Moghaddam Department of Petroleum and Chemical Engineering, Chemistry and Chemical Engineering Research Center of Iran, Postal Code: 1497716320, Tehran, Iran 0009-0000-6631-1782 Mahsa Baghban Salehi Department of Petroleum and Chemical Engineering, Chemistry and Chemical Engineering Research Center of Iran, Postal Code: 1497716320, Tehran, Iran 0000-0002-9097-919x Journal Article 2024 12 30 Hypothesis: Dual-network hydrogels, created by combining two interpenetrating polymer networks, demonstrate improved mechanical stability and selfhealing properties due to the presence of reversible dynamic bonds. These bonds allow the hydrogel to regain its original structure after suffering damage or stress. The distinctive characteristics of this type of hydrogel offer significant potential for a variety of applications in fields such as medicine, materials engineering, and developed technology. Methods: This study developed and investigated a self-healing hydrogel with a reversible dual-network structure made from polyvinyl alcohol (PVA) and varying amounts of acrylamide (AM). The hydrogel was synthesized using PVA, AM, borax as a crosslinker, and iron (III) ions, with ammonium persulfate (APS) serving as a radical polymerization initiator. To evaluate the structure, morphology, and performance of the synthesized hydrogel, several tests were conducted, including Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energydispersive X-ray spectroscopy (EDX) for microscopic surface morphology analysis thermogravimetric analysis (TGA), swelling behavior (in distilled water and 0/9% by wt saline solution), rheological measurements, and assessments of the hydrogel's self-healing capability. Findings: The results of the FTIR analysis confirmed the formation of the hydrogel structure and the presence of functional groups. SEM images showed that as the concentration of acrylamide (AM) increased, the hydrogel's structure changed from a smooth, non-porous surface to a mesoporous and homogeneous structure. At even higher concentrations of AM, a more compact and dense structure was observed due to increased crosslinking density Swelling behavior tests indicated that the PVA/PAM0.5 sample exhibited the highest equilibrium swelling. TGA results confirmed that the thermal stability of the hydrogels improved with higher concentrations of AM. Rheological evaluations revealed that the PVA/PAM0.5 hydrogel maintained its viscoelastic properties and fully recovered its structure after mechanical degradation Additionally, it demonstrated self-healing capabilities within 2 h at ambient temperature, without external stimulation. Hypothesis: Dual-network hydrogels, created by combining two interpenetrating polymer networks, demonstrate improved mechanical stability and selfhealing properties due to the presence of reversible dynamic bonds. These bonds allow the hydrogel to regain its original structure after suffering damage or stress. The distinctive characteristics of this type of hydrogel offer significant potential for a variety of applications in fields such as medicine, materials engineering, and developed technology. Methods: This study developed and investigated a self-healing hydrogel with a reversible dual-network structure made from polyvinyl alcohol (PVA) and varying amounts of acrylamide (AM). The hydrogel was synthesized using PVA, AM, borax as a crosslinker, and iron (III) ions, with ammonium persulfate (APS) serving as a radical polymerization initiator. To evaluate the structure, morphology, and performance of the synthesized hydrogel, several tests were conducted, including Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and energydispersive X-ray spectroscopy (EDX) for microscopic surface morphology analysis thermogravimetric analysis (TGA), swelling behavior (in distilled water and 0/9% by wt saline solution), rheological measurements, and assessments of the hydrogel's self-healing capability. Findings: The results of the FTIR analysis confirmed the formation of the hydrogel structure and the presence of functional groups. SEM images showed that as the concentration of acrylamide (AM) increased, the hydrogel's structure changed from a smooth, non-porous surface to a mesoporous and homogeneous structure. At even higher concentrations of AM, a more compact and dense structure was observed due to increased crosslinking density Swelling behavior tests indicated that the PVA/PAM0.5 sample exhibited the highest equilibrium swelling. TGA results confirmed that the thermal stability of the hydrogels improved with higher concentrations of AM. Rheological evaluations revealed that the PVA/PAM0.5 hydrogel maintained its viscoelastic properties and fully recovered its structure after mechanical degradation Additionally, it demonstrated self-healing capabilities within 2 h at ambient temperature, without external stimulation.

http://jips.ippi.ac.ir/article_2093_01b342cd6c2905b7a8e2bc970fed2b22.pdf