Carboxymethyl Tamarind-g-poly(acrylamide)/Silica: A High Performance Hybrid Nanocomposite for Adsorption of Methylene Blue Dye

Abstract

Here, synthesis of an efficient nanocomposite based on a polyacrylamide grafted carboxymethyl tamarind (CMT-g-PAM) and a SiO 2 nanoparticle is presented. The synthesized nanocomposites are characterized using FT-IR, SEM, TEM, 13 C NMR, elemental analysis, viscosity, rheological measurement, and molecular weight determination. Various characterizations reveal the existence of an excellent polymer matrix–nanoparticle interaction, which is at a maximum when 1.5 wt % of SiO 2 is introduced in the polymer matrix (i.e., CMT-g-PAM/SiO 2 -3). Nanocomposites show tremendous methylene blue (MB) dye adsorption capacity, because of their higher hydrodynamic radius as well as hydrodynamic volume, which originates from proper polymer matrix–SiO 2 nanoparticle interaction. CMT-g-PAM/SiO 2 -3 exhibited a maximum adsorption capacity ( Q max ) of 43.859 mg·g –1 . The adsorption behavior of the nanocomposite shows that adsorption kinetics and isotherms are in good agreement with pseudo-second-order and Langmuir equations, respectively. Negative values of Δ G ° confirmed the spontaneous nature of adsorption. Further, desorption experiments affirmed that the developed nanocomposite has excellent regenerative efficacy.