Effective Removal of Methylene Blue Dye Using Silver Nanoparticles Containing Grafted Polymer of Guar Gum/Acrylic Acid as Novel Adsorbent

In the present work, the synthesis of novel nanocomposite adsorbent based on graft copolymer of Poly(AA)/GG incorporated silver nanoparticles (AgNPs) has been carried out for the elimination of Methylene blue (MB) dye from the aqueous phase. The characterization of synthesized nanocomposite has been carried out by using various analytical techniques such as UV-Vis, FTIR, XRD, FE-SEM, EDX, DLS and BET studies. The UV-Vis, DLS and XRD studies revealed the stable formation of AgNPs inside the polymer matrix with an average size of 100 +/- 1 nm. The - 26.40 mV value of Zeta potential also confirms the stability of AgNPs inside the polymer matrix. Furthermore, the resultant adsorbent with an improved adsorption capacity is used to eliminate the MB dye from liquid phase. The parameters such as adsorbent dose and pH of dye solution in adsorption process are optimized. Moreover, the study of the adsorption kinetics and isotherm indicate that the pseudo-second-order kinetics and Langmuir isotherm model is more suitable for describing the experimental adsorption data having maximum adsorption capacity of 833.33 mg/g. Further, the positive values of enthalpy and entropy change specify that the adsorption of MB dye onto the surface of AgNPs/GG/Poly(AA) is endothermic, spontaneous and favorable process. Hence, In-situ synthesis of AgNPs inside polymer and grafting of AA as monomer onto GG has proven to be accountable for the substantial changes in adsorption capacity for removal of MB dye from aqueous phase. Therefore, the resultant AgNPs/GG/Poly(AA) nanocomposite may prove to be a noble adsorbent for the removal of MB dye from the liquid phase. [GRAPHICS] .