  The possibility of registration of quantum states, such as the coalescence of
droplets (tactoids) in the sol phase of aqueous vanadium pentoxide V$_2$O$_5$,
with positron annihilation lifetime spectroscopy is discussed. The decrease of
the long-living positronium (Ps) lifetime term in the result of the coalescence
of V$_2$O$_5$ tactoids is predicted.
