Investigating the effect of Graphene / Graphene Oxide on the crystallization and polymorphic stability of Ammonium Nitrate

Abstract. Ammonium nitrate (AN) is used extensively as a high nitrogen fertilizer and acts as an oxidiser in the energetic materials field. It is well known that its usage as part of a composite propellant is limited due to undesirable characteristics such as low burning rate, high hygroscopicity, low stability, and phase transformations. Even with these limitations, there is substantial interest nowadays in the development of AN based propellants as a replacement for Ammonium Perchlorate. This project studies the effect ofGraphene Oxide (G/GO) on the polymorphic stability, phase transition behaviour and crystal structure of AN. G/GOexhibits a number of properties such as large surface area, energetic reactivity, good thermal conductivity and strong mechanical properties which may enhance the behaviour of AN. This study examines the crystallisation and behaviour of AN when doped with G/GO, using a range of crystallisation methods and considers the effect of growth conditions in addition to the role of G/GO as a nucleating agent. This workshows that the behaviour of AN when crystallised in the presence of G/GO differs from that where AN is crystallised onto G/GO surfaces.