Synthesis, characterization, morphology and adsorption performance towards cu+2 ions of nano-sized copolymers of anthranilic acid and o-aminophenol poly(anthranilic acid-co-o-aminophenol)

Synthesis of N-isopropyl acrylamide copolymerized acrylic acid caped with Dibenzo-18-crown-6 composite for selective separation of Co-60 radioisotope from radioactive liquid waste containing Cs-137

A new selective polymeric composite capped with crown ether was successfully synthesized using N-isopropyl acrylamide copolymerized acrylic acid paired with Dibenzo-18-crown-6, P(NIPAm-Co-AA-DB 18C-6), by Gamma irradiation and ultrasonic homogenizer polymerization. Scanner electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and dynamic light scattering were used to characterize the selected polymeric composite's chemical and physical constitution. SEM shows a rough irregular surface, and FTIR spectra confirmed the function groups of P(NIPAm-Co-AA-DB 18C-6). Moreover, a systematic study of monomer and crown ether concentration was investigated to enhance the composite's performance. The behavior of the synthetic composite toward the selective separation of Co-60 from Cs-137 in a binary system was evaluated. Effects of pH, contact time, and initial ion concentration were investigated in a batch mode and the maximum capacity reached 108.0 mg/g for Co-60 and 82.0 mg/g for Cs-137. Four Kinetic models were investigated (pseudo-first-order, pseudo-second-order, Elovich, and Intra-particle diffusion). Regarding the calculated parameters, pseudo-second-order and Elovich models are the most describing the sorption process, indicating the chemisorptions process. Six adsorption isotherms were examined, two-parameter models (Langmuir, and Freundlich) and three-parameter models (Redlich-Peterson, Khan, Sips, and Hills). The best-fitted isotherm was identified using three error methodological approaches: the correlation coefficient (R2), the chi-square test (χ2), and the root-mean-square error. Isotherm models fit the experimental values in the following sequence: Khan > Rdlish-Peterson > Hills > Sips. Finally, an application for column separation was conducted, and Co-60 was completely separated from Cs-137 by 0.1 M HNO3. These findings indicate promising applications in the successive separation of Co-60 from radioactive liquid waste containing Cs-137 from Egyptian reactors.

Graphical abstract

Copolymerization of anthranilic acid and o-phenylenediamine by a free radical in the presence of nanoparticles of copper hexacyanoferrates for the removal of cesium ions in aqueous solutions

Core–shell nanocomposite of copper hexacyanoferrate copolymer of anthranilic acid with o-phenylenediamine (CHCF-poly-AA-co-OPD)) was synthesized and used as ion exchanger for the removal of cesium ions from wastewater. The nanocomposite was prepared by implantation of CHCF nanoparticles into the copolymer of poly(AA-co-OPD) during the polymerization process. By transmission electron microscope, scanning electron microscope and Brunauer–Emmett–Teller, the surface morphology and the porous structure were investigated. The physicochemical characterization of the prepared core–shell nanocomposite was carried out by FT-IR spectroscopy, XRD and thermogravimetric analysis. As a function in pH, metal ion concentration, shaking time and temperature, the capacity of the CSNC toward cesium ions and the behaviors of the process were studied. The results illustrated that the maximum capacity was recorded 1.35 mmol g−1 at pH 11, 10 mmol L−1 Cs+ and 25 °C. Also, Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D–R) isotherms models were studied, in which the data were well fitted with Langmuir model, suggesting that the uptake of Cs+ was monolayer and homogeneous. Also, the adsorption kinetics data were fitted well to pseudo-second-order model. Thermodynamic parameters were calculated in the temperature from 25 to 60 °C, and the data revealed that Cs+ sorption was endothermic, spontaneous and more favorable at higher temperature. Up to 92% desorption of Cs+ was completed with 2 M KCl.

Core–shell polymer nanocomposite based on free radical copolymerization of anthranilic acid and o-amino phenol in the presence of copper hexacyanoferrates nanoparticles and its adsorption properties

Core–shell polymer nanocomposite (CSNC) of copper hexacyanoferrate-copolymer of anthranilic acid with o-aminophenol (CHCF-poly(AA-co-OAP)) was synthesized and used as ion exchanger for the sorption of cesium ions from aqueous solution. The nanocomposite was prepared by implantation of CHCF nanoparticles into copolymer of poly(AA-co-OAP) during the polymerization process. The surface morphology and the porous structure were investigated through transmission electron microscope (TEM), scanning electron microscope (SEM) and Brunauer–Emmett–Teller (BET). The characterization of the prepared (CSNC) was carried out by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and Thermogravimetric (TGA). Which SEM and TEM images confirmed the nano-size of the prepared CSNC. The values of adsorption capacity of CSNC towards cesium ions and the factors influence on the removal of cesium from solutions were investigated as function in pH, metal ion concentration, temperature and contact time. The results illustrated that the highest value of sorption capacity of the prepared CSNC towards Cs+ ions was 2.1 mmol g−1 at pH 11, 10 mmol L−1 Cs+ and 25 °C. Four modeling include on Langmuir, Freundlich, Temkin and Dubinin-Radushkevich (D-R) isotherms models were studied. According to the obtained data, Langmuir model considered the most suitable model, which suggest that the uptake of Cs+ was monolayer and homogeneous. Also, the adsorption kinetics data was fitted well to pseudo-second-order model. Thermodynamic parameters were calculated in the temperature from 25 to 60 °C and the data revealed that Cs+ sorption was endothermic, spontaneous, and more favorable at higher temperature. Up to 92% desorption of Cs+ was completed with 2 M KCl.