Positron annihilation lifetime measurements in collagen biopolymer

Lifetime measurement in Positron Annihilation Spectroscopy (PAS) is applied to the study of free-volume collagen characteristics as a function of concentration. The lifetimes of positrons were measured by a conventional fast-fast coincidence system. All lifetime data are fitted in three components by using the computer program POSITRON-FIT and resolved. For each concentration, lifetime distributions were analyzed in order to obtain the different components, thus we have observed three components of which one long component τ₃. This long lived component can be associated with a pick-off annihilation of ortho-positronium (o-Ps) trapped in free volumes of amorphous region. This investigation shows the potential of positron annihilation spectroscopy in the study of biopolymer microstructures.