Resumo de eventos cient??ficos
Ionizing radiation for preservation
Registro en:
0000-0003-4168-1626
Autor
VASQUEZ, PABLO A.
NAGAI, MARIA L.
IAEA WORKSHOP ON INNOVATIVE APPROACHES OF ACCELERATOR SCIENCE AND TECHNOLOGY FOR SUSTAINABLE HERITAGE MANAGEMENT
Resumen
The Nuclear and Energy Research Institute ??? IPEN through the Multipurpose Gamma Irradiation
Facility and the Electron Beam Irradiation Facilities has disinfected several tangible cultural collections
from the University of S??o Paulo ??? USP. Brazilian weather conditions added to the actions
of insects and fungi promote biodegradation especially in cellulose based materials. In this sense,
ionizing radiation is an excellent alternative to the traditional preservation process mainly because
the biocidal action. Electron beam irradiation also presents new possibilities for processing materials
with greater speed, despite having limited penetration. Adequate storage of photographic and
cinematographic materials is a challenge for experts from preservation institutions. Contamination
by fungi is one of leading causes of problem in this kind of collections. In addition, another
common physicochemical degradation affecting cellulose triacetate films causing deacetylation of
polymer chain is called ???vinegar syndrome???. In this work are presented results of the effect of the
electron beam irradiation on photographic and cinematographic films using an electron beam accelerator
with energy of 1.5 MeV and beam power of 37.5 kW. Selected film samples were characterized
by FTIR-ATR spectroscopy and FEGSEM-EDS microscopy. Samples were irradiated with absorbed
dose between 2 kGy and 200 kGy. Irradiated samples were analyzed by UV-Vis spectrophotometry,
FEGSEM, thermogravimetric analysis (TG) and differential scanning calorimetry (DSC). Results
showed that disinfection by electron beam radiation can be achieved safely applying radiation absorbed
doses between 6 kGy to 10 kGy with no significant change or modification of main properties
of the constitutive polymeric materials. Electron beam irradiation, due to the effect of crosslinking
is presented as an alternative to treat films affected by ???vinegar syndrome??? applying absorbed dose
of 80 kGy in order to increase shelf life of cultural heritage materials.