Silica nanoparticles functionalized with amine polymer: Synthesis, characterization, application for removing copper and cadmium ions

In this research, silica nanoparticles are synthesized using Stöber method. To enhance the selectivity and adsorption properties of nanosilica, the nanoparticles are functionalized with novel linker and amine molecules to from a dendrimer polymer. The synthesized adsorbent is interrogated an effective adsorbent to eliminate copper and cadmium ions from aqueous samples. The structure, morphology and size of nanoparticles are examined using XRD, FT-IR, FE-SEM, TEM, EDX, TGA and UV-VIS methods. Afterwards, the extraction process is optimized by changing the effective parameters including adsorbent dosage, initial concentration of each ion, pH and time of contact. The maximum adsorption capacity of copper ion is calculated 25 mg/L by using 20 mg adsorbent at pH 7 in 24 minutes. Additionally, the maximum adsorption capacity of cadmium ion is 34 mg/L by applying 24 mg adsorbent dosage at pH 7 in contact time of 28 minutes. Therefore, the maximum adsorption capacity of the adsorbent for Cu(П) and Cd(П) ions at ambient temperature is equal to 70.9 and 69 mg/g, respectively. The adsorption isotherms of the copper and cadmium ions are in accordance with the Langmuir model and monolayer adsorption. Moreover, the kinetic absorption data proves the agreement with the pseudo-first-order model. This data is confirmed that the permeation occurs from inside a layer and it is based on the solid capacity. Additionally, the changes in the adsorption capacity with time are proportional to the unoccupied places on the absorbent surface. Furthermore, the synthetic nanoadsorbent is capable to be reused for 6 absorption-desorption cycles consecutively without a serious change in adsorption efficiency. • Silica nanoparticles are synthesized using Stöber method. • Nanosilica are functionalized with amine molecules to from a dendrimer polymer. • Synthesized adsorbent is applied as an adsorbent to remove heavy metal ions. • The maximum adsorption capacity for Cu 2+ and Cd 2+ are 70.9 and 69 mg/g, respectively. • The adsorption isotherms are in accordance with Langmuir model. • The adsorption kinetic is in agreement with pseudo-first-order model.