Titania modified gum tragacanth based hydrogel nanocomposite for water remediation

In this work, 2-hydroxyethyl methacrylate cross-linked gum tragacanth hydrogel (GumT-cl-HEMA) was systematically synthesized to attain maximum swelling (396.9 %) by simple microwave-assisted green polymerization technique. The prepared GumT-cl-HEMA hydrogel was further modified by using TiO₂ nanoparticles to generate TiO₂ loaded 2-hydroxyethyl methacrylate cross-linked gum tragacanth (GumT-cl-HEMA/TiO₂) hydrogel composite. The GumT-cl-HEMA hydrogel and GumT-cl-HEMA/TiO₂ hydrogel composite were characterized through XPS, BET, XRD, FTIR, TGA and SEM. The GumT-cl-HEMA hydrogel and GumT-cl-HEMA/TiO₂ hydrogel composite were used to perform adsorption to separate the molecules of malachite green (MG) from water. Batch adsorption parameters were examined to analyze the pH effect, time effect and adsorbent dose for the adsorption of malachite green dye from aqueous solution. The inclusion of TiO₂ particles inside the GumT-cl-HEMA hydrogel led to increased adsorption rates and stability. The adsorption was accurately followed the pseudo second order model and Langmuir isotherm model. The reported GumT-cl-HEMA/TiO₂ hydrogel composite removal efficiency was 99.3 % adsorbent dose = 90 mg, MG = 50 ppm, pH = 7, volume = 50 mL and time = 80 min). The synthesized samples were regenerated and then reused for five repeated adsorption-desorption cycles. The construction of GumT-cl-HEMA hydrogel and GumT-cl-HEMA/TiO₂ hydrogel composite gives a facile scheme for efficient adsorbents.