An influence of electron beam (EB) irradiation on the crack generation and propagation of transparent glasses are
studied by using a standard indentation fracture method. The thin (less than 0.5mm) transparent glass is used for
substrate of more than 100 inches crystal liquid display. However, it is difficult to product ultra thin and large-size
substrate without fracture. Therefore, these glasses have been expected to enhance the fracture toughness of
substrate for the displays.
As results, EB irradiation, which is one of short-time treatments of dry process at low temperature, increases the
crack nucleation energy of these glasses, although the EB irradiation does not change the crack propagation energy
of these glasses. The EB irradiation generates dangling bonds in these glasses. Partial relaxation of the residual
strain occurs around these dangling bonds in the silica network structure. If the inter-atomic distance of the
stronger metal-oxygen pairs becomes optimum on the potential curve of these glasses, the relaxation increases the
bonding energy of the network structure. Evidently, the enhancement of crack nucleation energy is mainly due to
an increase in the bonding energy for the stronger metal-oxygen atomic pairs in the atomic network structure, as
well as the relaxation of the network structure.
An effect of electron beam (EB) irradiation on wettability was studied for polypropylene for biomedical application. EB
irradiation enhanced the wettability on polypropylene samples. To discuss the effect, the wettability was evaluated by
using contact angle of sessile drop. EB irradiation decreased the contact angle. Based on ESR results, the effects of
electron beam on the wettability were discussed. EB irradiation broke the weakly bonded pairs and formed the dangling
bonds in polypropylene.
Effects of sheet electron beam irradiation on impact strength and wettability of alkali-free glass were studied. The irradiation, which was one of short-time treatments at low temperature below boiling point of water, enhanced impact value, whereas it decreased contact angle of alkali-free glass surface. EB irradiation also enhanced wettability and mist resistance.