Publications by authors named "Karel Stamberg"

Zirconium phosphate (ZrP), especially its alpha allotropic modification, appears to be a very promising sorbent material for the sorption and separation of various radionuclides due to its properties such as an extremely high ion exchange capacity and good radiation stability. Actinium-225 and its daughter nuclide Bi are alpha emitting radioisotopes of high interest for application in targeted alpha therapy of cancer. Thus, the main aim of this paper is to study the sorption of Ac on the α-ZrP surface and its kinetics, while the kinetics of the sorption is studied using Eu as a non-radioactive homologue of Ac.

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The overall need for the preparation of new medicinal radionuclides has led to the fast development of new sorption materials, extraction agents, and separation methods. Inorganic ion exchangers, mainly hydrous oxides, are the most widely used materials for the separation of medicinal radionuclides. One of the materials that has been studied for a long time is cerium dioxide, a competitive sorption material for the broadly used titanium dioxide.

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The work deals with the evaluation of biochar samples prepared from Phyllostachys Viridiglaucescens bamboo. This evaluation consists of the characterization of prepared materials' structural properties, batch and dynamic sorption experiments, and potentiometric titrations. The batch technique was focused on obtaining basic sorption data of ⁸⁸ᵐTcO₄⁻ on biochar samples including influence of pH, contact time, and Freundlich isotherm.

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The study summarizes the results of monitoring the properties of two types of sorbents, BC1 (biochar sample 1) and BC2a (biochar sample 2), prepared by pyrolysis of bamboo biomass (BC1) and as its composite with montmorillonite K10 (BC2a). The main goal was to study their applicability to the Tc (VII) separation from liquid wastes, using NHReO as a carrier. The research was focused on determining the sorbents surface properties (by XRF (X-ray fluorescence) method and potentiometric titration in order to determine the properties of surface groups-Chemical Equilibrium Model (CEM) and Ion Exchange Model (IExM) models were applied here).

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Sorption kinetics of radium on hydroxyapatite and titanium dioxide nanomaterials were studied. The main aim of the current study was to determine the rate-controlling process and the corresponding kinetic model, due to the application of studied nanomaterials as α-emitters' carriers, and to assess the sorption properties of both materials from the radiopharmaceutical point of view by time regulated sorption experiments on the nanoparticles. Radium-223 was investigated as radionuclide used in targeted alpha particle therapy as an in vivo generator.

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The mechanism of Ra uptake on hydroxyapatite and titanium dioxide nanoparticles was studied as a function of pH. Both materials are widely used in food industry and medicine. They offer properties suitable for labelling with medicinal radionuclides, particularly for targeted radionuclide therapy.

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We provide characterization data of hydroxyapatite (nHAp) and titanium dioxide (nTiO) nanoparticles as potential materials for ion sorption, in targeted therapy, barrier materials for waste repositories or photovoltaics. The study is focused on the determination of the values of protonation and ion exchange constants and site densities (∑SOH, ∑X; [mol kg]) of nTiO and nHAp for further Ra kinetics and sorption experiments. These data are very important for further investigation of the materials, which can be used as drug delivery systems or in engineered barriers of deep geological repositories.

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Two members of the tetradentate N-donor ligand families 6,6'-bis(1,2,4-triazin-3-yl)-2,2'-bipyridine (BTBP) and 2,9-bis(1,2,4-triazin-3-yl)-1,10-phenanthroline (BTPhen) currently being developed for separating actinides from lanthanides have been studied. It has been confirmed that CyMe4-BTPhen 2 has faster complexation kinetics than CyMe4-BTBP 1. The values for the HOMO-LUMO gap of 2 are comparable with those of CyMe4-BTBP 1 for which the HOMO-LUMO gap was previously calculated to be 2.

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Kinetics of Pu(IV) and Am(III) sorption from natural groundwater to three types of clays were studied at trace concentrations of the elements. Higher K(d) values were determined for sorption of Pu than of Am, and no clear dependence of the K(d) values and the kinetic coefficients on the composition of the clays can be deduced. Kinetic data evaluated by models for six different control processes indicated a sorption mechanism controlled by Pu or Am diffusion in the inert layer on the surface of the clays.

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