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Cerium dioxide as a new reactive sorbent for fast degradation of parathion methyl and some other organophosphates

Journal of Rare Earths 2014年第4期32卷 360-370页

作者： Pavel Janos Pavel Kuran martin kormunda Vaclav Stengl Tomas Matys Grygar Marek Dosek martin Stastny Jakub Ederer Vera Pilarova Lubos Vrtoch Faculty of the Environment University of Jan Evangelista Purkyne Faculty of Science University of Jan Evangelista Purkyne Institute of Inorganic Chemistry AS CR v.v.i.

Cerium dioxide was used for the first time as reactive sorbent for the degradation of the organophosphate pesticides para-thion methyl, chlorpyrifos, dichlofenthion, fenchlorphos, and prothiofos, as well as of some chemical warfare agents-nerve gases soman and O-ethyl S-[2-（diisopropylamino） ethyl] methylphosphonothioate （VX）. CeO2 specimens were prepared by calcination of basic cerous carbonate obtained by precipitation from an aqueous solution. The CeO2 samples containing certain amounts （1 wt.%-5 wt.%） of the neighboring lanthanides （La, Pr, Nd） were prepared in a similar way from pure lanthanide salts. It was shown that ceria accelerated markedly the decomposition of parathion methyl causing the cleavage of the P-O-aryl bond in the pesticide molecule. A similar reaction mechanism was proposed for the degradation of other organophosphate pesticides and nerve agents. The degradation times （reaction half-times） were in an order of minutes in the presence of CeO2, compared to hours or days under common environ-mental conditions. The reaction in suitable organic solvents allowed conversions of about 90%for parathion methyl loading of 20 mg pesticide/g CeO2 within 2 h with a reactant half-life in the order of 0.1 min. The key parameter governing the degradation efficiency of CeO2 was the temperature during calcination. At optimum calcination temperature （about 773.15 K）, the produced ceria retained a sufficiently high surface area, and attained an optimum degree of crystallinity （related to a number of crystal defects, and thus poten-tial reactive sites）. The presence of other lanthanides somewhat decreased the reaction rate, but this effect was not detrimental and permitted the possible use of chemically impure ceria as a reactive sorbent. A fast organophosphate degradation was demonstrated not only in non-polar solvents （such as heptane）, but also in polar aprotic solvents （acetonitrile, acetone） that are miscible with water. This opens new possibilities for designi

关键词： cerium dioxide carbonate precursor lanthanides organophosphate pesticide parathion methyl chemical warfare agents hydrolysis non-aqueous solvents rare earths

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Unveiling the nanotoxicological aspects of Se nanomaterials differing in size and morphology

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Bioactive Materials 2023年第2期20卷 489-500页

作者： Hana Stepankova Hana Michalkova Zbynek Splichal Lukas Richtera Pavel Svec Tomas Vaculovic Jan Pribyl martin kormunda Simona Rex Vojtech Adam Zbynek Heger Department of Chemistry and Biochemistry Mendel University in BrnoZemedelska 1BrnoCZ-61300Czech Republic Central European Institute of Technology Brno University of TechnologyPurkynova 123BrnoCZ-61200Czech Republic Department of Chemistry Masaryk UniversityKamenice 5BrnoCZ-62500Czech Republic Institute of Laboratory Research on Geomaterials Faculty of Natural SciencesComenius University in BratislavaMlynska dolinaIlkovicova 684215 BratislavaSlovak Republic Central European Institute of Technology Masaryk UniversityKamenice 5BrnoCZ-62500Czech Republic Department of Physics Faculty of ScienceJ.E.Purkyne UniversityPasteurova 1Usti nad LabemCZ-40096Czech Republic

Although the general concept of nanotechnology relies on exploitation of size-dependent properties of nanoscaled materials,the relation between the size/morphology of nanoparticles with their biological activity remains not well ***,we aimed at investigating the biological activity of Se nanoparticles,one of the most promising candidates of nanomaterials for biomedicine,possessing the same crystal structure,but differing in morphology(nanorods *** particles)and aspect ratios(AR,11.5 vs.22.3 vs.1.0)in human cells and BALB/c ***,we report that in case of nanorod-shaped Se nanomaterials,AR is a critical factor describing their cytotoxicity and ***,spherical nanoparticles(AR 1.0)do not fit this statement and exhibit markedly higher cytotoxicity than lower-AR Se *** of cytotoxicity,we also show that morphology and size substantially affect the uptake and intracellular fate of Se *** line with in vitro data,in vivo *** of Se nanomaterials revealed the highest toxicity for higher-AR nanorods followed by spherical nanoparticles and lower-AR ***,we revealed that Se nanomaterials are able to alter intracellular redox homeostasis,and affect the acidic intracellular vesicles and cytoskeletal architecture in a size-and morphology-dependent *** the tested nanoparticles were produced from the similar sources,their behavior differs markedly,since each type is promising for several various application scenarios,and the presented testing protocol could serve as a concept standardizing the biological relevance of the size and morphology of the various types of nanomaterials and nanoparticles.

关键词： Aspect ratio Biocompatibility Nanotoxicology Nanorods

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