Gamma radiation effects in vertically aligned carbon nanotubes

Abstract

This paper describes an experimental study of gamma radiation effects in low-density arrays of vertically aligned carbon nanotubes. These arrays are characterized by excellent anti-reflective and absorbing properties for wavelengths from UV to IR which makes them an interesting option for stray light control in optical space applications. Gamma irradiation equivalent to an estimated surface life-time exposition in geostationary orbit does not affect the reflectivity of the structures. First high-energy proton irradiation studies indicate that the reflectivity of the carbon nanotubes forests remains unchanged.

Tuning the grade of graphene: Gamma ray irradiation of free-standing graphene oxide films in gaseous phase

“…The presence of oxygen gas in air leads to a slight increase of the oxygen rich groups content across the surface of the GO sheets. On the other hand the presence of hydrogen, and the lower ionization energy required to form hydrogen radicals, resulted in clear reduction of oxygen rich sites across the GO sheets and to some degree of re-graphitisation without noticeable increase of morphological defects [28]. This last point was also supported, as seen in Fig.…”

“…Alternative non-invasive functionalization routes, such as hard X-ray lithography, were previously shown to lead to effective and specific functionalization of thick arrays of carbon nanotubes by interfering with the surface electronic density of the graphitic walls in air, which lead to the formation of highly crystalline, but yet hydrophilic nanotubes [27]. Recently, radiation chemistry by gamma ray irradiation, a simple and efficient strategy to uniformly induce chemical reactions in solutions via production of reactive radicals [27,28] has been used to reduce GO suspended either in aqueous solution or organic solvents [29][30][31][32][33][34][35]. Radicals, such as ethoxy or hydronium [36,37] generated across the solvent act as reducing agents against oxygen functional groups present on the GO surface.…”