Search Results

You are looking at 1 - 5 of 5 items for

  • Author or Editor: G. Müllen x
  • All content x
Clear All Modify Search

Abstract  

The fractionation factor of tritium between water and biomoleculeswhich are structured by hydrogen bridges, is found to be around 2. In additionto an intramolecular accumulation, an extra-molecular one is found to be about1.4 in the hydration sheets. During growth of plants (maize), the growth incrementof tritium in non-exchangeable organically bound tritium (OBT) is about 2.4times (140% larger than) the growth increment of hydrogen. The intrinsic growthrate of tritium is about 20 percent larger than that of hydrogen. Tritiumbound in water overtakes its kinetic delay in photosynthetic or metabolicreactions according to the larger mass by the fast established thermodynamicisotope effect of proton-triton exchange.

Restricted access
Restricted access

Abstract  

Cryosublimation is one technique, which allows the accumulation of tritium from aqueous solutions using certain chemical compounds. After studying several inorganic compounds such as zeolites and metal salts,1 as well as some humic substances,2 we have now investigated several mono-and polysaccharides, such as glucose, maltose, galactose, starch, agar, and gelatine. Except for starch all of the above mentioned compounds showed a clear enrichment of tritium. The highest value was reached for Agartine, which gave an enrichment factor of 6.2. Since mono-and polysaccharides form weak hydrogen bonds, these results prove again our theory that tritium is preferably accumulated in exchangeable hydrogen bonds.

Restricted access

Summary  

Tritium exchange and enrichment was studied for several different metal salts, e.g., AlF3 . H2O, FeO(OH), CsI, CsF, NaI, NaF and Al(OH)3 using a cryosublimation apparatus. Experiments were performed below equilibrium vapor pressure to avoid any isotope effects. A comparable tritium enrichment factor of 1.14 to 1.43 was obtained for all systems, except for CsF, which gave an enrichment factor of 1.93. These results confirm the concept, that 3H is accumulated in weak hydrogen bonds as already observed in organic molecules.

Restricted access
Journal of Thermal Analysis and Calorimetry
Authors: J. Mullens, G. Reggers, M. Ruysen, R. Carleer, J. Yperman, D. Franco, and L. Van Poucke

Abstract  

The oxidative degradation of HET-acid (1,4,5,6,7,7-hexachlorobicyclo [2.2.1] hept-5-en-2, 3-dicarboxylic acid) is studied by the combination of TG, FTIR, MS and GC-MS. The gases evolved during the decomposition of this flame retardant are investigated on-line by FTIR and by MS. Simultaneously the evolved gases are collected by an adsorbent and, after the thermal experiment, desorbed to release the volatile products for identification using GC-MS. The combination of these techniques offers the unambiguous identification of the evolved products as a function of temperature. The main identified products are CO2, H2O, Cl2, HCl, C2Cl4, maleic acid anhydride, HET-acid anhydride, chlorinated cyclic hydrocarbons and chlorinated unsaturated linear hydrocarbons.

Restricted access