Effect of γ-irradiation on hexagonal boron nitride membranes and printed films†

Liquid phase exfoliation (LPE) enables cost-effective and scalable production of two-dimensional (2D) materials that are suitable for fabrication of protection films and barrier coatings, through simple and low-cost techniques. Amongst 2D materials, hexagonal boron nitride (hBN) is very attractive for these applications due to its exceptional thermal and chemical stability. However, use of hBN coatings and films in environments such as reactor inspection, spent nuclear fuel handling, reprocessing facilities, or spacecraft components, which often involve elevated temperatures and/or the presence of reactive chemical species, require the protective coatings to retain their chemical, mechanical, or thermal performance under prolonged radiation exposure. In this study, we investigate the radiation tolerance to γ-rays of printed hBN films fabricated by inkjet printing and membranes produced by vacuum filtration, up to a total absorbed dose of 1500 kGy in different atmospheric conditions. Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) reveal no significant structural differences in the samples up to the maximum absorbed dose, indicating excellent radiation tolerance under the conditions tested. Additionally, we did not observe structural changes in the irradiated hBN films even after prolonged exposure to air for two months. The exceptional radiation tolerance and environmental stability of the printed hBN films and membrane make them attractive as protective coatings or insulating layers in various advanced technologies for the nuclear and aerospace sectors, where long-term material stability to γ-rays is crucial.