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Brought to you by | University of Queensland -UQ Library Authenticated Download Date | 6/16/15 11:58 PM Gamma Radiation Treatment of Paper 108 included in the trials the Whatman Paper, in order to check, once again, the effects of irradiation on those chemical and physical properties that can be measured only on pure cellulose, for example the degree of polymerisation.The main negative effects of radiation on the paper (observed through viscometric and infrared spectroscopic measurements) are: the formation of unsaturated components, which do not pertain to the structure of the polymer, and the depolymerisation of cellulose, which is proportional to the absorbed radiation 4 . The ageing of paper also influences these effects. Therefore, it was decided to combine the radiation treatment with other treatments that could moderate the formation and the action of free radicals, which are principally responsible for the depolymerisation of cellulose 5 . Two series of experiments were arranged: the effects of oxygen removal in the first, and water soaking in the second. This latter experiment also attempted to simulate the effects of irradiation on already deteriorated paper, imitating, for example the situation after a flood. Moreover, we controlled the in vivo effect of radiation on the microbial flora. Finally, the effect of irradiation after a certain time was verified. All the samples, having undergone the different experimental treatments, were compared with a similar series of samples. which were submitted to accelerated ageing.In brief, the objectives of the present work were:• to verify the effects of radiation on commercial paper and, for some parameters, on cellulose;• to confirm the effect of the ionising radiation to reduce the microbial flora;• to verify the ability of some treatments associated with irradiation: to increase the decontaminating action of radiation, and/or to reduce the negative effects of irradiation on paper;• to verify the action of irradiation on paper over time.The objective of the experimental work was not only to find the most relevant structural changes induced by the decontamination treatment. We also aimed at evaluating the effects of these changes, in view of a costs/benefits analysis, which has to be calculated before proposing the method on a large scale.

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