The Interaction of Graphene/Graphene Oxide Surfaces and the Effect on Crystal Growth of Ammonium Nitrate

Abstract

Ammonium Nitrate is an inorganic salt that is made from Nitric Acid and Ammonia. It is commonly used as an explosive in commercial applications such as mining, quarrying, and tunneling works. It could be used in the defence field as an oxidiser in rocket propellants. It is a cheap oxidiser and explosive, but it has many disadvantages compared to conventional alternatives; it is very hygroscopic, has low polymorphic stability, and poor ballistic performance. Graphene Oxide is one monomolecular layer of graphene that contains oxygen functional groups such as carboxyl and hydroxyl groups. It has many interesting properties such as being thermally stable and has promising electric and permeating properties due to its unique structure. It is used in water filtration membranes, biomedical applications, and electronics. Introducing Graphene Oxide (a material already used in composite propellants to improve burn rates and moisture blockage) to Ammonium Nitrate crystals may improve AN’s polymorphic properties such as phase stability and transition thresholds. This project aims to investigate the surface interactions between Graphene Oxide substrates at varying oxygen content and Ammonium Nitrate crystals. The crystals are grown using cooling and evaporation crystallisation techniques. Different analyses are performed including X-Ray Diffraction, Atomic Force Microscopy, and Sessile Drop studies to give a detailed study of the interactions between Graphene Oxide and Ammonium Nitrate. It was found that 15% Graphene Oxide provided a Two-way stabilizing effect for AN III and IV phases. While 25-30% Graphene Oxide portrayed a behavior that is like amorphous glass.