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

Here, synthesis of an efficient nanocomposite based on a polyacrylamide grafted carboxymethyl tamarind (CMT-g-PAM) and a SiO2 nanoparticle is presented. The synthesized nanocomposites are characterized using FT-IR, SEM, TEM, C-13 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 SiO2 is introduced in the polymer matrix (i.e., CMT-g-PAM/SiO2-3). 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-SiO2 nanoparticle interaction. CMT-g-PAM/SiO2-3 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 Delta G(o) confirmed the spontaneous nature of adsorption. Further, desorption experiments affirmed that the developed nanocomposite has excellent regenerative efficacy.