The present study deals with the adsorption of arsenic ions from aqueous solution on polyaniline/rice husk (PAn/RH) nanocomposite. Batch studies were performed to evaluate the influence of various experimental parameters like pH, adsorbent dosage, contact time and the effect of temperature. Optimum conditions for arsenic removal were found to be pH 10, adsorbent dosage of 10 g/L and equilibrium time 30 minutes. Adsorption of arsenic followed pseudo-second-order kinetics. The equilibrium adsorption isotherm was better described by Freundlich adsorption isotherm model. The adsorption capacity (q max ) of PAn/RH for arsenic ions in terms of monolayer adsorption was 34.48 mg/g. The change of entropy (∆S 0 ) and enthalpy (∆H 0 ) was estimated at −0.066 kJ/(mol K) and −22.49 kJ/mol, respectively. The negative value of the Gibbs free energy (∆G 0 ) indicates feasible and spontaneous adsorption of arsenic on PAn/RH.

In this work, Functional Fe3O4@ polydopamine nanocomposite (Fe3O4@PDA) with magnetic response and special surface area were successfully assembled utilizing the strong coordination interactions between these two versatile materials. The morphology and size, crystal structure, specific saturation magnetization, chemical structure, and thermal properties were characterized by transmission electron microscopy (TEM), X‐ray diffraction (XRD), vibration magnetometer (VSM), point of zero charge (pHpzc), Fourier infrared (FT‐IR) and thermogravimetric analysis (TGA). The self‐polymerization of dopamine could be completed within 3 days, and Fe3O4 nanoparticles were embedded into PDA polymer. TGA results showed that PDA content of nanocomposite can be up to 51.7 wt% and also showed a significant decrease in the decomposition temperature of PDA from 530 to 270°C in the presence of the Fe3O4 nanoparticles. Through TGA analysis the coating thickness was estimated to be about 0.86 nm that it is well coincident with the measured values using TEM images and XRD analysis. At room temperature by vibrating sample magnetometer (VSM), Fe3O4 and Fe3O4@PDA exhibit superparamagnetic behavior with a saturation moment of 57.87 and 44.7 emu/g, respectively. Furthermore, PZC value reduced for Fe3O4@PDA compared with Fe3O4 nanoparticles and fell from 6.7 to 3.04. J. VINYL ADDIT. TECHNOL., 25:41–47, 2019. © 2018 Society of Plastics Engineers

No abstract

No abstract