Preparation of superabsorbent eco-friendly semi-interpenetrating network based on cross-linked poly acrylic acid/xanthan gum/graphene oxide (PAA/XG/GO): Characterization and dye removal ability

• Published in: International journal of biological macromolecules 2020-06, Vol.152, p.884-893
• Main Authors: Hosseini, Seyed Mostafa, Shahrousvand, Mohsen, Shojaei, Shahrokh, Khonakdar, Hossein Ali, Asefnejad, Azadeh, Goodarzi, Vahabodin
• Format: Article
• Language: English
• Subjects: Acrylic Resins - chemistry; Adsorption; Coloring Agents - chemistry; Coloring Agents - isolation & purification; Graphene oxide (GO); Graphite - chemistry; Green Chemistry Technology; Hydrogels; Methylene blue; Methylene Blue - chemistry; Methylene Blue - isolation & purification; Models, Molecular; Molecular Conformation; Poly (acrylic acid) (PAA); Polysaccharides, Bacterial - chemistry; Superabsorbent; Temperature; Water Pollutants, Chemical - chemistry; Water Pollutants, Chemical - isolation & purification; Xanthan gum (XG)
• ISSN: 0141-8130; 1879-0003
• DOI: 10.1016/j.ijbiomac.2020.02.082

In this work, a novel environmentally friendly semi-interpenetrating anionic hydrogel based on Xanthan gum/cross-linked polyacrylic acid/graphene oxide was prepared as superabsorbent for removing methylene blue as cationic dye from the water. Acrylic acid (AA) was crosslinked in xanthan (XG)/graphene oxide (GO) solution by a novel synthetic acrylic-urethane crosslinker (MS). Various analyses such as SEM, FT-IR, 1H NMR, XRD, and TGA were used to study morphology, structure, and thermal stability of MS and semi-IPNs. The synthesized hydrogels showed pH-sensitive behavior in water uptake, with the highest and lowest swelling in alkaline and acidic media, respectively. The nanocomposites had better dimension stability and dye adsorption with increasing GO from 0 to 1%. Hydrogel containing 1% GO showed 485% and 88.5% swelling and dye adsorption efficiency, respectively. Different kinetic models including 1st order, 2nd order, intra-particle diffusion, and Elovich kinetics were studied. All models except 2nd order model are in good agreement with the experimental data. GO-containing hydrogels had a significant effect on methylene blue adsorption and this effect increased with an increase in the amount of GO. PAA/XG/GO hydrogels can be introduced as an eco-friendly adsorbent with high efficiency for the removal of cationic dye pollutions. [Display omitted]