Macromolecular scintillators

The synthesis and properties of heat-resistant polyazomethines containing 2,5-disubstituted oxadiazole fragments, being insulators convertible into semiconductors by doping with iodine, have been described. The radical copolymerization of alkenes with the fluorescent co-monomer 2-/-butyl-5-(4 -vinyl-4-biphenylyl)-l,3,4-oxadiazole has resulted in useful macromolecular scintillators. Anionic polymerization of 2-phenyl-l,3,4-oxadiazolin-5-one has produced a nylon-type product <1996CHEC-II(4)268>. 

The excimer photophysics of the two macromolecular scintillators studied has been shown to be too complex to be described by either a kinetic model which includes isolated monomer sites or one which considers a time dependent rate of quenching. This is attributed to the existence in each case of more than one and possibly a distribution of conformations of excimer with an associated spectrum of decay times. 

The diffracted beams are detected and their intensities measured by use of a scintillation counter or by use of photographic film the latter is subsequently photometered. An area detector is used for many macromolecular studies. 

Fig. 1. Rates of protein synthesis in poliovirus-infected and mock-infected HeLa cells. The curves shown were generated from numerous experiments in which HeLa cells were incubated for 15 min with radiolabeled amino acids at various times postinfection or mock infection with poliovirus. The cells were harvested immediately following the labeling period, and incorporation of amino acids into macromolecular protein was determined by scintillation spectroscopy of TCA-precipitable material.

---