Tomasz Szreder

Instytut Chemii i Techniki Jądrowej · Centre for Radiation Research and Technology

Background: Advanced Oxidation Processes (AOPs) are the water treatment techniques that are commonly used forthe decomposition of the non-biodegradable organic pollutants. However, some pollutants are electron deficient and thus resistant to attack by reactive oxygen species (e.g., polyhalogenated compounds) but they may be degraded under reductiv...

Modification of pulse radiolysis (PR) setup and construction of a new laser flash photolysis (LFP) setup at the Institute of Nuclear Chemistry and Technology (INCT) is described. Both techniques are dedicated to studying fast reactions in real time by direct observation of transients. Time resolution of the PR setup at INCT was ~11 ns, limited by t...

The methyl ester of p-hydroxybenzoic acid (methylparaben, MP) is commonly used as a preservative in cosmetics, food and pharmaceuticals. Its widely examined interactions with aqueous system and human organisms prove a necessity of the monitoring of its release to natural environment and the efficiency of its removal from waters and wastewaters. In...

The mechanism of high-energy radiation induced degradation of perfluorooctanoate anion (PFOA, C7F15COO⁻) was investigated in aqueous solutions. Identification and quantification of transient species was performed by pulse radiolysis and of final products by gas and ion chromatography, electrochemical method using fluoride ion-selective electrode an...

In this work, the feasibility of sterilizing a water suspension of poly‐3‐hexylthiophene nanoparticles (P3HT‐NPs) is investigated using ionizing radiation, either γ‐rays or high‐energy electrons (e‐beam). It is found that regardless of the irradiation source, the size, polydispersity, aggregation stability, and morphology of the NPs are not affecte...

The source of the residues of anthropogenic endocrine disruptor known as bisphenol A (BPA) in the natural environment and foods is both production and very wide use of several classes of polymers. Because of the documented inefficiency of BPA removal from waters and wastewaters using conventional treatment methods, several advanced oxidation proces...

In our studies we have focused on two major POP's-representants: tetrabromobisphenol-A (4,4’-isopropylidenebis(2,6-dibromophenol), TBBPA) and perfluorooctanoic acid (PFOA).

The mechanism of radiation-induced fast reactions occurring in the early stages in the 1-octanol system containing 2,9-Bis-(5,5,8,8-tetramethyl-5,6,7,8-tetrahydro-benzo (Herbst et al., 2011; Nash et al., 2015; Bourg et al., 2015)triazin-3-yl)- (Herbst et al., 2011; Panak and Geist, 2013)phenanthroline (CyMe4-BTPhen) extracting agent were studied. T...

The reaction of hydroxyl radical (HO•) with DNA produces many primary reactive species and many lesions as final products. In this study, we have examined the optical spectra of intermediate species derived from the reaction of HO• with a variety of single- and double-stranded oligodeoxynucleotides and ct-DNA in the range of 1 μs to 1 ms by pulse r...

The radiolytic methods of PFOS decomposition in aqueous solutions investigated in this work for potential environmental applications are based on the use of gamma rays or a beam of accelerated electrons (EB) under different chemical conditions in irradiated solutions. The most active reagents in the employed conditions are hydrated electrons from w...

The photoreduction by amines and N-phenylglycine, NPG, of six styryl-quinoxalin-2(1H)-ones derivatives substituted in the styryl moiety, R-SQ, was studied by using flash photolysis. The photoreaction is initiated via a single electron transfer from the electron donor (amines or NPG) to R-SQ excited triplet state, 3R-SQ*, with the formation of a tri...

It has been demonstrated through the use of both gamma-rays and beam of accelerated electrons (EB) for the radiolytic decomposition of PFOA in diluted aqueous solutions that the most reactive species among the products of water radiolysis are hydrated electrons eaq. The reaction of PFOA with the hydrated electrons takes place with the largest yield...

The introduction to chemistry of water radiolysis, production of radicals, and radical reactions is followed by characterization of different kinds of ionizing radiation, and technological installations employed for irradiation of waters and wastewaters for their purification and remediation. The main features of radiation technology include the po...

The monitoring of Advanced Oxidation/Reduction Processes (AO/RPs) for the evaluation of the yield and mechanisms of decomposition of perfluorinated compounds (PFCs) is often a more difficult task than their determination in the environmental, biological or food samples with complex matrices. This is mostly due to the formation of hundreds, or even...

The most important contributions of radiation chemistry to some selected technological issues related to water-cooled reactors, reprocessing of spent nuclear fuel and high-level radioactive wastes, and fuel evolution during final radioactive waste disposal are highlighted. Chemical reactions occurring at the operating temperatures and pressures of...

In the present study we synthesized a shape-persistent molecule featuring four bipyridinium units that upon reduction undergoes intermolecular pimerization because of the rigid architecture of the molecule. The pimerization process has been investigated by a variety of techniques, like, absorption measurements, EPR, gamma and pulse radiolysis, and...

The original version of this article unfortunately contained mistakes concerning some units of measurement: (Table presented).

The most important contributions of radiation chemistry to some selected technological issues related to water-cooled reactors, reprocessing of spent nuclear fuel and high-level radioactive wastes, and fuel evolution during final radioactive waste disposal are highlighted. Chemical reactions occurring at the operating temperatures and pressures of...

1-Octanol/kerosene mixtures and water contacted with organic solvents were used as model solutions for r-SANEX and i-SANEX extractions systems. Investigations aimed on a quantitative evaluation of gaseous products generated in these systems under exposure to an electron beam irradiation. Influence of O2, HNO3 and the presence of model ligands and c...

Gaseous products generated as a result of ammonium, pyrrolidinium and imidazolium ionic liquids (ILs) exposure to ionizing irradiation were under investigations. The main aim was to find out an influence of an aromatic substituent on the radiation chemistry of ILs. Therefore, in each selected ILs groups, an alkyl substituent in an IL cation was rep...

Photoreduction of 7H-benzo[e]perimidin-7-one (3-AOIA, A1) and its 2-methyl derivative (2-Me-3-AOIA, A2) by non-H-donating amines (1,4-diazabicyclo[2.2.2]octane [DABCO]; 2,2,6,6-tetramethylpiperidine [TMP]), and a hydrogen-donating amine (triethylamine [TEA]), has been studied in deaerated neat acetonitrile solutions using laser flash photolysis (LF...

Hydrophobic room-temperature ionic liquids (ILs) hold promise as replacements for molecular diluents for processing of used nuclear fuel as well as for the development of alternative separations processes, provided that the solvent can be made resistant to ionizing radiation. We demonstrate that 1-benzylpyridinium cations are uniquely suited as rad...

On time scales of a nanosecond or less, radiolytically-generated excess electrons in ionic liquids undergo solvation processes and reactions that determine all subsequent chemistry and the accumulation of radiolytic damage. Using picosecond pulse radiolysis detection methods, we observed and quantified the solvation response of the electron in 1-me...

The thermostability of glucose oxidase entrapped in silica gel obtained by sol-gel method was studied by thermostimulated fluorescence of FAD at pH 5 and 7 and compared with that of the native enzyme in the solution and at the presence of ethanol. The unfolding temperatures were found to be lower for the enzyme immobilised in gel as compared with t...

The pairing of a Lindqvist or Keggin polyoxometalate (POM) anion with an appropriate tetraalkylphosphonium cation, [R{sub 3}R{prime}P]{sup +}, has been shown to yield an original family of ionic liquids (POM-ILs), among them salts liquid at or near ambient temperature. The physicochemical properties of several such 'inorganic liquids', in particula...

Pairing of a Keggin or Lindqvist polyoxometalate (POM) anion with an appropriate tetraalkylphosphonium cation is shown to yield the first members of a new family of ionic liquids (ILs). Detailed characterization of one of them, an ambient-temperature "liquid POM" comprising the Lindqvist salt of the trihexyl(tetradecyl) phosphonium cation, by volta...

The pairing of selected polyoxometalate (POM) anions with appropriate tetraalkylphosphonium cations, which display an original family of ionic liquids, is discussed. The ionic liquids exhibit both an ability to solvate a remarkable variety of organic and inorganic materials and negligible vapor pressures, making the liquid solids potential green re...

In chemically amplified resists for ionizing radiations such as electron beams and extreme ultraviolet (EUV), low-energy electrons play an important role in the pattern formation processes. The reactivity of acid generators with low-energy electrons was evaluated using solvated electrons in tetrahydrofuran, which were generated by a pulsed electron...

Time resolved absorption spectra of trapped electrons generated in pulse irradiated polypropylene film containing irganox 1076 are investigated at ∼100K. Antioxidant influences the yield and decay of near-ir electrons in the matrix under consideration.

Luminescence from electron-irradiated polypropylene doped with naphthalene and pyrene was investigated in the temperature range 77–273 K. Excimer emission of the aromatic admixture was observed in the temperature range 240–260 K of the high temperature radiothermoluminescence peak where the glass transition was recorded. The mechanism of solute exc...

The ionic and excited species generated in pure and doped polypropylene (PP) film were studied using pulse radiolysis over a wide temperature range ca 30-295 K. Electron (6-8 MeV) pulse irradiation generated electron-positive hole pairs. The electron was stabilized in the undoped systems as a trap electron. In the presence of electron scavengers, C...

A pulse radiolysis study of isotactic polypropylene (PP) film has been carried out with the main aims of investigating charge trapping in an undoped system and solute radical ion generation in an pyrene (Py) doped matrix. In PP, pulse radiolysis gives electron–positive hole pairs. The electron can be stabilized in the undoped system as a trapped el...

The study of oxidized polypropylene, undoped and doped with pyrene was carried out with the main aim of investigating energy and charge transfer in these systems. The transient absorption spectrum of trapped electrons was not detected in the case of oxidized polypropylene because of electron scavenging by products of polymer oxidation (peroxides an...