Carbon nano tubes functionalized with novel functional group- amido-amine for sorption of actinides

Neutron Activation Analysis of Rare Earth Element Extraction from Solution through a Surfactant-Assisted Dispersion of Carbon Nanotubes

We report the preparation of surfactant-assisted carbon nanotube dispersions using gum arabic, Triton X-100, and graphene oxide as dispersing agents for removing rare earth elements in an aqueous solution. The analytical tools, including (a) scanning electron microscopy and (b) neutron activation analysis, were utilized for qualitative and quantitative examinations, respectively. Neutron activation analysis was employed to quantitatively determine the percent of extraction of nuclides onto the carbon structure, while the images produced from the scanning electron microscope allowed the morphological structure of the surfactant-CNT complex to be analyzed. This report tested the effects responsible for nuclide removal onto CNTs, including the adsorbent to target mass ratio, the CNT concentration and manufacturing process, the pH, and the ionic radius. Observable trends in nuclide extraction were found for each parameter change, with the degree of dispersion displaying high dependency.

Gamma radiation-induced preparation of chitosan-acrylic acid-1-vinyl-2-vinylpyrrolidone/multiwalled carbon nanotubes composite for removal of 152+154Eu, 60Co and 134Cs radionuclides

Removal behaviors of ^152+154Eu, ⁶⁰Co, and ¹³⁴Cs radionuclides onto Chitosan-acrylic acid-1-vinyl-2-vinylpyrrolidone/oxidized multi-walled carbon nanotubes (CTS-AA-VP/o-MWCNTs) composite has been investigated by batch adsorption technique. CTS-AA-VP/o-MWCNTs composite has been synthesized by copolymerization of acrylic acid (AA) and 1-vinyl-2-vinylpyrrolidone (VP) onto the surface of chitosan/oxidized multi-walled carbon nanotubes (CTS/o-MWCNTs) using gamma radiation. SEM, TGA, and FTIR were applied to characterize the morphology, thermal stability, and structure of the composite. The composite shows high removal capacity of 321.77, 369.91, and 456.46 mg/g towards ^152+154Eu, ⁶⁰Co, and ¹³⁴Cs radionuclides, respectively.

One-pot synthesis of sodium lauryl sulfate-loaded polyacrylonitrile solid-phase extractor for investigating the adsorption behavior of radioactive strontium(II) from aqueous solutions

Sodium lauryl sulfate-loaded polyacrylonitrile (SLSLPAN) was synthesized in the present investigation using an in-situ one step process through gamma radiation-induced polymerization. The structure, composition, surface area and pore size and volume of the employed adsorbent were investigated by Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD) and nitrogen adsorption-desorption measurements. Adsorption of radioactive strontium(II) onto SLSLPAN was studied in the pH range 3-13. Batch kinetic data showed that the equilibrium was attained at 840 min and the pseudo-first-order was the best kinetic model for describing the kinetic data of the present adsorption process. The diffusion of strontium(II) into SLSLPAN was deeply studied using four diffusion models, namely, Bangham, Boyd, Weber-Morris and Mathewas-Weber models. Two-parameter (Freundlich, Langmuir and Temkin) and three-parameter (Redlich-Peterson, Toth and Generalized) isotherm models were used to analyze the adsorption equilibrium data of strontium(II) onto SLSLPAN. The maximum adsorption capacity calculated by the Generalized isotherm model is found to be 0.391 mmol strontium(II) per gram of SLSLPAN. The estimated mean free energy (E = 2.151 kJ/mol) indicated that strontium(II) radionuclides were physically adsorbed onto SLSLPAN. The value of enthalpy change (ΔH^o = 35.325 kJ/mol) and those of free energy change (ΔG^o = -15.278, -16.948, -18.619 and -20.288 at 303, 313, 323 and 333 K, respectively) confirmed that adsorption of strontium(II) radionuclides on SLSLPAN was endothermic and spontaneous process.

Exploring functionalized titania for task specific application of efficient separation of trivalent f-block elements

Functionalized titania, obtained by grafting the dipicolinic acid functionality, was explored for task specific application of highly efficient separation of trivalent f-block elements.

Investigating the effects of amine-functionalized carbon balls in a polybenzoxazine matrix

This study contains arithmetical and experimental examinations of the effects of adding carbon nanoballs (CBs) on the curing behavior and material properties of a benzoxazine system.

Synthesis of amino-functionalized magnetic aerobic granular sludge-biochar for Pb(II) removal: Adsorption performance and mechanism studies

In the present study, a novel amino-functionalized magnetic aerobic granular sludge-biochar (NH₂-M-AGS) was successfully fabricated through magnetization and functional modification and applied for Pb(II) sorption. The composite was characterized by using scanning electron microscopy (SEM), energy dispersive spectrum (EDS), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Zeta potential analysis, vibrating sample magnetometer (VSM) and X-ray photoelectron spectroscopy (XPS). The effects of adsorbent dosage, pH value, contact time and initial metal concentration on the adsorption of Pb(II) were investigated by using batch equilibrium experiments. It was concluded that the pseudo-second-order model was better to describe adsorption kinetic of Pb(II) onto NH₂-M-AGS. The Langmuir model was more accorded with the experimental data, and the maximum adsorption capacity of Pb(II) was 127.0 mg/g. A possible adsorption mechanism could be mainly caused by surface complexation, electrostatic attraction and precipitation. In five adsorption-desorption cycles, the desorption efficiency of Pb(II) exhibited a slight decline and still reached at 88.14%. Furthermore, the good reproducibility indicated that NH₂-M-AGS could be used a desirable, economic and recyclable adsorbent in practical metal-contaminated wastewater treatment.

Preparation of chitosan functionalized polyamidoamine for the separation of trivalent lanthanides from acidic waste solution

The manuscript deals with the sorption of Am(III) and Eu(III) from pH medium using chitosan functionalized with dendrimer like polyamidoamine (PAMAM) polymers up to third generation. The PAMAM polymers were introduced into chitosan by two step processes and were characterized by various instrumental techniques like FTIR, XRD, TG-DTA. The sorption process was highly pH dependent for both Am(III) and Eu(III) with increasing trend for higher pH of the solution. Kinetics of equilibration was found to be fast with equilibrium attained in 10 min for both the metal ions. Pseudo 2nd order kinetics mechanism was found to be followed for both Am(III) and Eu(III). The sorption process of Eu(III) was found to fit the Langmuir isotherm model with maximum sorption capacity of 6.01 mg/g. There was no effect on the generation of PAMAM Dendron on the efficiency, kinetics or sorption capacity for Am(III) as well as Eu(III). The synthesized different generation of PAMAM functionalized chitosan is a promising material for removal of actinides and lanthanides from waste water solution.