Papers by Keyword: Hydrogel

Abstract: Synthetic dyes such as methyl orange (MO) are persistent water pollutants that pose serious environmental and health hazards due to their toxicity and resistance to biodegradation. Developing efficient, sustainable, and reusable adsorbents for dye removal remains a major challenge in wastewater treatment. This study presents the design and optimization of chitosan/polyethyleneimine/graphene oxide (CS/PEI/GO) hydrogel nanocomposite beads synthesized through controlled cross-linking with glutaraldehyde (GLA) for enhanced adsorption of MO from aqueous solutions. A Box–Behnken experimental design coupled with response surface methodology (RSM) was employed to evaluate the effects of PEI, GO, and GLA concentrations on adsorption capacity. Statistical analysis confirmed the high significance of the cubic model (F = 38.34, p = 0.0001) with a non-significant lack of fit, validating its strong predictive reliability. PEI concentration had the most pronounced effect, providing protonated amine sites for electrostatic interaction with the anionic dye, while GO increased surface area and provided oxygen-containing groups that enhanced hydrogen bonding and π–π interactions. GLA served as a cross-linker to stabilize the hydrogel structure without deactivating active sites. The optimized composition (2.0% PEI, 900 ppm GO, and 2.5% GLA) achieved a predicted adsorption capacity of 23.16 ± 1.05 mg/g, which closely matched the experimentally obtained value of 23.31 ± 1.19 mg/g, with only 2.2% deviation. These findings confirm that the CS/PEI/GO hydrogel nanocomposite provides a balanced integration of structural stability, functional site availability, and high adsorption efficiency, demonstrating its potential as a scalable, eco-friendly material for advanced dye removal and sustainable wastewater treatment.

Abstract: Industrial wastewater often contains colored toxic dyes and heavy metals that harm ecosystems and human health, highlighting the need for sustainable treatment strategies. This study aimed to develop a guar gum (GG)/polyacrylamide (PAAm)/rice straw biochar (RSBC) hydrogel grafted onto polyethylene terephthalate (PET) (GG/PAAm RSBC-g-PET) textile, and its structure was characterized through swelling behavior, FTIR-ATR spectroscopy, and Scanning Electron Microscopy (SEM) analysis. The modified GG/PAAm/RSBC-g-PET exhibits a significant increase in water absorption compared to GG/PAAm-g-PET. The alteration and shifted peaks were observed particularly at bands of 3441 cm^-1 (RSBC), and 852 cm^-1 (galactose and mannose units), imparting effective crosslinking. SEM analysis revealed a porous structure with irregular magnetite particles, enhancing the active surface area. The performance of the GG/PAAm/RSBC-g-PET composite was evaluated using industrial wastewater, which resulted in reduced turbidity (26.5 NTU) and color (~49.5 ADMI), compared to filtration with PET textile alone (47 NTU and ~69.5 ADMI). The GG/PAAm/RSBC-g-PET composite exhibits comparable yet inconsistent improvements, possibly due to particle release and pore blockage. These findings demonstrate the feasibility of the GG/PAAm/RSBC-g-PET textile for decolorization, indicating its potential application in wastewater remediation.

Abstract: This research explored the synthesis of hydrogels from acrylamide-grafted durian rind cellulose using a microwave-assisted method. The objective of this research was to investigate the effect of cellulose preparation and duration of microwave irradiation on the swelling properties of the obtained bead hydrogel. The mixture of cellulose, acrylamide solution, and potassium peroxydisulfate as the initiator agent was irradiated by microwave at 640 W. FTIR analysis showed that acrylamide was grafted into durian rind cellulose successfully. This study found that bead gels from durian rind cellulose, which underwent delignification and bleaching methods, exhibited a greater swelling capacity (855%) after 180 minutes than bead gels from durian rind cellulose without these methods (807%). The optimum microwave irradiation time was found to be 540 s, resulting in a maximum swelling capacity of 676%.

Abstract: This study presents the possibilities of using a fire extinguishing agent based on a water-soluble polymer for extinguishing fires at facilities where the fire load is formed by liquid combustible materials. It has been theoretically and experimentally shown that by changing the concentration of gelling additives, the viscosity can be varied, which, in turn, directly affects the characteristics of the protective layer created by applying the gel fire extinguishing agent to the surface of the combustible liquid.. The results of an experimental study of the effectiveness of gel fire extinguishing agents based on a polymer of the ECOFLOC A-18 type are presented. A method for preparing liquid solutions of concentrates of aqueous fire extinguishing agents with a gelling agent concentration of up to 10 %, which are easy to dissolve in water or in a foaming agent, is proposed. It is noted that their concentration should be such that when creating a working solution, the amount of gelling agent in it is not less than 0.05 % for the use of the solution in extinguishing fires.

Abstract: This article describes the development and characterization of a curcumin-loaded alginate-xanthan gum hydrogel, designed to provide both antibacterial activity and controlled drug release.The hydrogel formulation consisted of 4% (w/v) alginate, 4% (w/v) xanthan gum, and 500 μg/mL of curcumin. Sterilization was achieved through ethanol immersion, UV irradiation, and autoclaving, with the latter two methods proving to be the most effective in maintaining long-term sterility. Antibacterial efficacy was tested against Staphylococcus aureus, demonstrating a significant inhibition zone around the hydrogel. The curcumin release profile indicated a sustained release over 72 hours, suggesting its suitability for prolonged antibacterial applications.

Abstract: The present research proposes the comparison of chitosan zinc nanocomposites in the form of membranes and hydrogels. Three concentrations (0.2, 0.4, and 0.6 wt%) of zinc (Zn) nanoparticle inclusion were used to create the chitosan nanocomposites for enhanced biological applications. Statistical analysis was performed with sample size N=16, an alpha error of 0.5, 95% confidence interval (CI), and G-power at 80%, The nanocomposite variations were analyzed for their improved capabilities against chitosan for its antibacterial activity (mm), water uptake (%), and other visual parameters including SEM and FTIR. Independent T-test through SPSS software revealed that both nanocomposites were statistically significant with (p = 0.01, p<0.05) and (p=0.026, (p>0.05)). The current study proposes novel chitosan with zinc nanocomposites with enhanced biological activity and offers a future scope for improved biomedical applications.

Abstract: У даному дослідженні представлені можливості використання вогнегасної речовини на основі водорозчинного полімеру для ліквідації пожеж на полігонах ТПВ та полігонах побутових відходів, пожежне навантаження яких утворюється за рахунок твердих горючих матеріалів. Теоретично та експериментально показано, що шляхом зміни концентрації гелеутворювальних добавок можна змінювати в'язкість, що безпосередньо впливає на швидкість випаровування та глибину проникнення вогнегасної речовини в осередок пожежі. Наведено результати експериментальних досліджень ефективності гелевих вогнегасників на основі полімеру ECOFLOC A-07.

Abstract: Hydrogels, a type of polymer, can be synthesized from both natural and synthetic sources, including some biopolymers like alginate and chitosan, making them particularly interesting for biomedical applications. The popularity of hydrogels in the medical field is due to their high-water content, flexibility, and biocompatibility. Hydrogels, which can swell in a hydrated state, are capable of controlling the release of active substances in pharmaceutical and biomedical applications. Alginate and chitosan exhibit polyanionic and polycationic properties when dissolved under appropriate conditions, allowing them to interact with each other. This interaction occurs through the carbonyl groups of alginates and the amino groups of chitosan. Alginate also has the advantages of being non-toxic, biodegradable, biocompatible, and non-allergenic. Therefore, these two materials readily form polyelectrolyte complexes. The use of calcium chloride in producing hydrogels is due to its ability to perform ionic cross-linking on polymers such as alginate. Calcium chloride reacts with the carboxylate groups in alginate, forming stable cross-links between polymer chains. This cross-linking process results in a three-dimensional network that provides structure and stability to the hydrogel. The benefits of adding CaCl₂, in addition to facilitating cross-linking, include increasing the viscosity of the alginate solution, which enhances the formation of the alginate matrix. This study demonstrates that the ratio of chitosan to alginate significantly influences the properties of the resulting hydrogel, impacting its swelling ratio, stability, and ultimately, its potential for biomedical applications. Specifically, the optimal ratio of 5A:1C exhibited superior swelling and gel fraction characteristics, suggesting its potential suitability for controlled drug delivery systems. The successful cross-linking confirmed by FTIR analysis further strengthens the viability of this specific composition for biomedical applications.

Abstract: Natural carbonated composites are formed by calcium carbonate crystals embedded within an organic matrix that the living organism excretes. In this study, a solvent made with sodium alginate, glycerol and sodium hydroxide was used to promote the mineralisation of biomimetic calcium carbonate. Carbon dioxide was captured and stored as a carbonate binder composite, and the cementitious mechanism toward sand particles was revealed. The binder composite comprises amorphous calcium carbonate, calcium alginate-glycerol gel and calcite. Organic additives were crucial to promote the mineralisation of the most stable calcium carbonate polymorph, calcite. The final calcite crystals presented a peanut-like shape, detached from a structured sea urchin-like particle. An estimated 0.15 tonne of carbon dioxide could be permanently stored in 1 tonne of the biomimetic calcium carbonate and sand composite. The composite block presented a compressive strength and elastic modulus of 0.85 and 21.3 MPa, respectively. It is believed that the cementitious mechanism of the carbonate binder composite is formed through the crystallisation of amorphous calcium carbonate (ACC) embedded inside a three-dimensional organic gel enriched with calcium ions into calcite. Hence, calcium carbonate mineralisation mediated by sodium alginate and glycerol introduces new possibilities to create a novel, more sustainable, environmentally friendly binder material.

Abstract: This study focuses on synthesizing and characterizing a semi-Interpenetrating Network (semi-IPN) elastomeric hydrogel comprising natural rubber (NR) and polyethylene glycol methacrylate (PEGMA) for efficient removal of Methylene Blue (MB) dye from aqueous solutions. The impact of varying PEGMA/NR ratios (100/0 to 0/100) was investigated. SEM images displayed a porous and uniform structure with interconnected pores of different sizes. FTIR analysis confirmed the formation of a semi-IPN structure, showcasing functional groups in both NR and PEGMA. Adsorption studies revealed the hydrogel's efficacy in MB dye removal, achieving a maximum adsorption capacity of 6536 mg/g at a PEGMA/NR ratio of 90/10. UV-vis spectroscopy validated the reduction in MB concentration post-exposure to the hydrogel. These findings highlight the cationic ionic nature of the PEGMA/NR semi-IPN elastomeric hydrogel as a promising adsorbent for MB dye removal in wastewater applications, particularly in industrial wastewater treatment.