Abstract—This study introduces a novel hydrogel design in which the combined incorporation of itaconic acid and Titanium dioxide (TiO₂) nanoparticles into an alginate–acrylic matrix creates a synergistic structure with enhanced functional groups, improved stability, and superior adsorption performance. This dual organic–inorganic modification distinguishes the material from conventional hydrogels and represents a meaningful advancement in dye-removal hydrogel systems. A Sodium Alginate (SA) based hydrogel was synthesized through free-radical copolymerization of Acrylic Acid (AA) and Itaconic Acid (IA), followed by incorporation of TiO₂ nanoparticles as functional and reinforcing additives. The structure of the SA-g-(AA-co-IA)/TiO₂ hydrogel was confirmed by Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and Thermogravimetric Analysis (TGA). SEM revealed a porous network with uniformly distributed TiO₂ nanoparticles, while XRD indicated a semi-crystalline matrix retaining TiO₂ crystalline phases. TGA showed improved thermal stability in TiO₂-loaded hydrogels. The material exhibited strong swelling behavior, reaching up to 800% of its dry weight, and demonstrated clear pH-responsive properties. In dye-removal tests, pristine TiO₂ showed low adsorption, whereas the composite hydrogel achieved a 91.2% removal efficiency for Brilliant Green (BG), significantly outperforming the unloaded hydrogel (73.4%). Isotherm analysis indicated that the adsorption followed the Freundlich model, indicating multilayer adsorption. The maximum adsorption capacity (Qₘ = 162.22 mg/g) indicated strong interactions between BG molecules and the hydrogel surface. These results highlight the synergistic role of TiO₂ NPs and the copolymer network in enhancing adsorption performance. The developed hydrogel represents a promising multifunctional material for wastewater treatment and other stimuli-responsive applications.
Keywords—acrylic-itaconic acid, Titanium dioxide, brilliant green, pH-responsive hydrogel, biopolymer nanocomposite
Cite: Uday Abdul-Reda Hussein, Ali Fawzi Al-Hussainy, Wasam Naj, Alzahraa S. Abdulwahid, Hadil Hussain Hamza, Aseel M. Aljeboree, and Ayad F. Alkaim, "TiO₂-Reinforced Alginate-Acrylic-Itaconic Acid Hydrogel for Efficient Brilliant Green Adsorption," International Journal of Environmental Science and Development vol. 17, no. 3, pp. 292-300, 2026.
Copyright © 2026 by the authors. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).