R. Čech

Determination of radiolytic products of two-phase tributylphosphate—Water systems by capillary isotachophoresis

A capillary isotachophoresis was used for determination of ionogenic radiolytic products of two-phase tributylphosphate—water systems. Optimum operating conditions for analytical determination of dibutylphosphate (DPP), monobutylphosphate (MBP), H3PO4, formic, acetic, propionic and butyric acid were found.

Radiolysis of carbon tetrachloride-nitrobenzene mixtures. Radiation yields of major liquid products

The yields of major non-gaseous radiolytical products in the mixtures of carbon tetrachloride-nitrobenzene in a wide concentration scale have been established and found to depend on the composition of the mixture. Decrease of the yield hexachloroethane with increasing concentration of nitrobenzene was explained by the energy transfer from CCl4 to the molecule of C6H5NO2. Chlorobenzene is formed from an exciplex [CCl4.C6H5NO2]* or complex with charge transfer or from reaction of the excited molecules of nitrobenzene, and the formation of dichlorobenzenes, trichlorobenzenes and chloronitrobenzene can be explained by radical substitutional reactions.

Determination of radiation yields of ionogenic products of two-phase water-dibutylphosphate systems by capillary isotachophoresis

The main ionogenic radiolytical degradation products are monobutylphosphate, phosphoric acid, formic, acetic, propionic and butyric acids as the result of gamma-irradiation of two-phase water-dibutylphosphate system. The products were determined using capillary isotachophoresis. According two-phase theory the total (TG(X)) and partial (GI(X) for aqueous phase and GII(X) for organic phase) radiation yields of products and decomposition of DBP in the radiolysis of two phase water-dibutylphosphate systems were calculated from the results.

Determination of radiation yields of ionogenic products of two-phase water-tributylphosphate and water-di-(2-ethylhexyl)-phosphoric acid systems by capillary isotachophoresis

It was found that the main ionogenic radiolytical degradation products of tributylphosphate were monobutylphosphate dibutylphosphate, phosphoric acid, formic, acetic, propionic and butyric acids as the result of gamma-irradiation of two-phase water-tributylphosphate system. In the case of irradiation of two-phase water-di(2-ethylhexyl)-phosphoric acid system, the main radiolytic degradation products are 2-ethylhexylphosphoric acid and phosphoric acid. All products were determined using isotachophoresis. According two-phase theory the total and partial radiation yields of products were calculated from the results.

Two-phase formation of nitrophenols at the radiolysis of nitrobenzene-water emulsions

Two-phase additivity rule for radiation yields of p-nitrophenol, m-nitrophenol and p-nitrosophenol has been demonstrated. The data of partial radiation yields indicated that the nitrobenzene phase is by several times more reactive than a water phase /H2O, 3M HNO3 or 1.5M H2SO4/ in respect of nitrophenols formation.

Radiation yields of phenol derivatives in nitrobenzene-water systems

Abstract Radiolysis of nitrobenzene was studied in two-phase systems with water, sulfuric acid and nitric acid solutions. In kinetic regime of radiolysis the two-phase additivity rule was applied to calculate partial radiation yields of p -nitrophenol, m -nitrophenol, p -nitrosophenol, 2,4-dinitrophenol, 2,5-dinitrophenol, o -nitroaniline and o -, m -, p -aminophenols in the systems of various volume ratios. Nitrobenzene phase was found to be several times more reactive than the aqueous one in respect of the phenols and aniline derivatives formation. In the absence of agitation the yields depend strongly on the thickness of the phases irradiated, as it ensues from the diffusion regime theory of radiolysis in biphasic systems, which was illustrated.

Radiolysis of the trichloromethane-water two-phase system

The radiolysis of the CHCl3-water two-phase system in the absence of oxygen has been investigated by continuous γ-ray irradiation. The major products of radiolysis were determined to be the same, except for tetrachloromethane, as in the case of the radiolysis of pure CHCl3, however, the radiolytical yields were different. The dependencies of gross radiation yields of the radiolysis products on the CHCl3 volume fraction follow the two-phase rule of additivity. The partial yields of all products determined were calculated for both phases and revealed that the major products HCl and C2H2Cl4 are formed in both phases. The other organic products are formed mainly in the organic phase. The decrease of organic product yields is probably caused by the presence of water in the organic phase. The radiolysis of CHCl3-water did not proceed in the diffusional regime even at high absorbed doses due to the relatively high solubility of CHCl3 in water andvice versa.

Radiation stability of benzyldibutylamine in benzene in the presence of nitric acid

We have investigated the influence of the presence of nitric acid on the stability of benzyldibutylamine in the organic phase irradiated by a dose of 143 kGy. The composition of degradation products of radiolysis in individual chromatographic fractions was identified by means of mass, NMR and IR spectra and elemental analysis. It follows from the mass blance that benzyldibutylamine is stable with gamma-radiation of medium-high dose and that its mass loss does not exceed 22% of the irradiated fraction.

Radiolysis of tetrachloromethane-water two-phase systems

Abstract The radiolysis of two-phase systems CCl 4 -water proceeds in kinetical regime up to dose 12 kGy. Groos radiation yields of chloride ions are the same as the radiolysis of saturated solutions in this period. A two-phase rule of additivity is valid and the partial yields for both phases were calculated; G CCl 4 (Cl - = 5.61 ± 0.10 and G H 2 O (Cl - ) = 8.29 ± 0.51 molecules/100 eV, respectively. The radiolysis proceeds in diffusional regime at the absorbed dose of more than 50 kGy. The gross radiation yield of chloride ions is determined by hydrolysis of molecular chlorine which is produced with G (Cl 2 ) = 0.68 ± 0.14 molecules/100 eV. An additional part of chloride ions is produced by radiolysis of substrates which diffuse into both phases with value G dif (Cl - ) = 2.38 ± 0.31 molecules/eV. This value is approximately three times less than the gross radiation yields in kinetical regime of radiolysis of two-phase systems in saturated solutions of these substrates.

Radiation and quantum yields of Cl- ions in chlorobenzene, carbon tetrachloride and water two-phase systems

Abstract The ɣ-radiolysis of unstirred two-phases systems of water-carbon tetrachloride and water-chlorobenzene and the dependence of total radiation-chemical yields of Cl- ions from the partial volume of phase II (organic phase) has been examined. From this dependence, the partial yields IG(Cl-) and IIG(Cl-) for water and organic phase has been calculated, respectively. The photolysis of two-phases systems has been investigated under the conditions similar to irradiation experiments and the quantum yields were compared.