Dendritic polymer immobilized on nanosilica: An effective and recyclable adsorbent for the removal of copper ions from aqueous system

This study demonstrates a synthetic strategy for the preparation of porous SiO۲ using natural and waste materials from rice husks as the source of biosilica. Biogenic porous silica nanoparticles with a mean diameter of ۴۵ nm were successfully prepared from rice husk (RH) biomass via a multistep method. During the first step, sodium silicate is extracted from rice husks. Then, cetyltrimethylammonium bromide (CTAB), HCl, and HOAc were added into sodium silicate solution, and the resulting mixture was sonicated. After the hydrothermal reaction, the collected samples were calcinated to obtain silica nanoparticles. Then, dendritic polymer supported on nanosilica with surface amino groups were fabricated. The synthesized nanostructures were characterized by Fourier transform infrared (FT-IR) spectroscopy, thermogravimetric analysis (TGA) and dynamic light scattering (DLS). Also, the morphologies of the sorbent were characterized using a field emission scanning electron microscope (FE-SEM) and a transmission electron microscope (TEM). The adsorption isotherm studies of the novel adsorbent in removing heavy metals from waste water showed that the maximum absorption amounts of Cu(П) were ۱.۲۴ mmol/g at ۴۵ oC. The excellent adsorption capacity of the nSiO۲-dendrimer nanoadsorbents plus their easy separation, and reusability makes them more suitable adsorbents for the removal of metal ions from wastewater.

کلیدواژه ها:

Rice husk ash ، Silica nanoparticles ، dendritic polymer ، Removal of copper ions ، Adsorption isotherms ، Adsorption Kinetics