Physical chemistry of lyoluminescence
The emission of light on dissolution of irradiated saccharides and amino acids has boon studied. This phenomenon is referred to as lyoluminosconco.The physico-chemical mechanism underlying the phenomenon is based on the production of radicals when the solid material is exposed to ionizing radiation. Autoxidation of "trapped" radicals to poroxyl radicals is accelerated on dissolution. Disproportionation of poroxyl radicals produces excited carbonyl triplet, triplet ground state oxygen and ringlet ground state alcohol. Quenching of the emission from carbonyl triplet by oxygen molecule in the solvent cage generates singlot oxygen. The contribution from singlet oxygen simultaneous transition involvingmolecular pairs (1r., 1,4 ), (1Q , 1Q) depends largelyon the degree of quenching in the solvent cage.cement of the natural lyoluminescence (LL) was studied in aqueous solutions containing fluorescent dyes, chelated and non-chelated rare earth ions. In the presence of trivalent terbium ion, the LL from glutamine is enhanced by a factor 1900 times for threonine,700 times for glutamine240 times for serine and about 52 times for glucose.The enhancement in solution containing europium and dysprosium ions is about 70 and 80 times respectively for glutamine. In terbium citrate, lyoluminescence from glutamine was enhanced by about 423 times. Enhanced emission was observed during the dissolution of irradiated mannose in aqueous solution of micelles containing diphenylisobenzofuran and aqueous solution of eosin.Radical recombination and transformation under given experimental conditions (post-irradiation storage temperature and humidity, solvent pH and dissolved oxygen concentration) results in the variation of lyoluminosconce yield.Lyoluminescence dosimetry with 6Lithium pyruvate offers the best combination for measuring exposures to neutron irradiations.