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Tetraphenyldithiodiphosphonate is synthesized by polymerization precipitation. The P = S bond of the material has strong polarity, which is conducive to improving the electron mobility of the complex and inhibiting the accumulation between molecules. The synthesized tetraphenyldithiodiphosphonate is characterized by FT-IR, SEM, XPS and XRD. In addition, the pseudo-second-order kinetic model is used to simulate the experimental data well, and the adsorption process conforms to the Langmuir isotherm model. Thermodynamic studies of adsorption have shown that the adsorption process is essentially a spontaneous endothermic process. At room temperature, tetraphenyldithiodiphosphonate demonstrates a maximum adsorption capacity for uranium(VI) reaching 398.8 mg g−1. [ABSTRACT FROM AUTHOR]

Poly(cyclotriphosphazene-co-polyethyleneimine) microspheres with the solid structure were synthesized by precipitation polymerization method for the separation of highly toxic uranium(VI). The structure and morphology of the prepared microspheres were analyzed via FTIR, SEM–EDS, TEM and BET. The optimal adsorption conditions were also investigated, and the maximum adsorption capacity was 274.2 mg g−1. The experimental results showed that the adsorption kinetics conformed to the pseudo-second-order kinetics and was in good agreement with the Langmuir adsorption isotherm model. Removal of uranium(VI) ions was achieved by the complexation between the amino groups on the adsorbent and uranyl ions. [ABSTRACT FROM AUTHOR]

Highly crosslinked organic–inorganic hybrid polymer poly(cyclotriphosphazene-co-melamine) microspheres (PZM) were synthesized by a simple method. The microspheres was characterized by FTIR, SEM and EDX. It was applied to eliminate thorium(IV) from aqueous solution under various conditions, i.e., pH, initial concentration, dosage and contact time. The experimental data were well-imitated via the pseudo-second-order kinetic model and its adsorption processes comply with the Langmuir isotherm model. Adsorption thermodynamic studies demonstrated that the adsorption process, in essence, was spontaneous and endothermic. Furthermore, the maximum experimental adsorption capacity was 98.6 mg g−1 for initial thorium(IV) concentration 50 mg L−1. When pH = 0.0, the thorium(IV) removal efficiency reached at 76.9%, which indicates that the adsorbent can also was used in a peracid environment. Adsorption behavior of thorium(IV) onto the microspheres were weakly affected via temperature, implying that adsorption would be done at room temperature. [ABSTRACT FROM AUTHOR]

Poly(cyclotriphosphazene-co-4,4′-diaminodiphenyl ether) microspheres (PZA) was based on hexachlorocyclotriphosphazene (HCCP) and 4,4′-diaminodiphenyl ether (ODA). It was synthesized via one-step precipitation method. The PZA microspheres were characterized by FT-IR, XPS, zeta potential and SEM/EDS. Through experimental research, PZA microspheres had the optimal adsorption performance with pH value 3.5, contact time of 60 min, thorium(IV) ions concentration of 30 mg L−1, and PZA microspheres of 10 mg. The maximum adsorption capacity of PZA microspheres for thorium(IV) was 29.04 mg g−1. The adsorption process could be described by the quasi-second order kinetic model and simulated by the Langmuir isotherm equation. [ABSTRACT FROM AUTHOR]

A new synthetic method was designed to prepare poly (trimesoyl chloride-co-polyethyleneimine) (PEI-TMC). Characterization of PEI-TMC was investigated by FTIR, SEM, EDS, XPS, TGA, and BET. TGA test revealed that the PEI-TMC had excellent thermal stability. The BET specific surface area (4.74 ​m2 ​g−1) and pore diameter of about 9.44 ​nm indicated that PEI-TMC possessed a mesoporous structure. The adsorption behavior of U(VI) on the PEI-TMC was investigated. The thermodynamic analysis showed that the process of PEI-TMC adsorption of U(VI) was endothermic and spontaneous, and the adsorption efficiency was better at higher temperatures. The U(VI) sorption on PEI-TMC was conformed to the Langmuir adsorption isotherm and pseudo-second-order kinetic models. The adsorption mechanism of U(VI) with PEI-TMC was systematically elucidated by XPS and FTIR. Under the best condition, the maximum adsorption capacity of PEI-TMC could reach 212.8 ​mg ​g−1 ​by calculating the Langmuir isothermal model. It indicated that PEI-TMC was a potential adsorbent for the treatment of U(VI)-containing wastewater. Diagram of PEI synthesis and its adsorption mechanism for U(VI). Image 1 • A new and facile method is used to prepare PEI-TMC. • The application field of PEI-TMC was expanded for the separation of U(VI). • Excellent adsorption performance was demonstrated. [ABSTRACT FROM AUTHOR]