Ammonium nitrate: a promising rocket propellant oxidizer

In this review data from the literature on thermal decomposition of ammonium nitrate (AN) and the effect of additives to their thermal decomposition are summarized. The effect of additives like oxides, cations, inorganic acids, organic compounds, phase-stablized CuO, etc., is discussed. The effect of an additive mainly occurs at the exothermic peak of pure AN in a temperature range of 200°C to 140°C.

Review on Thermal Decomposition of Ammonium Nitrate

Ground-state structures and vibrational frequencies are calculated for complexes of the nitrate anion with one and two water molecules at the ab initio Hartree–Fock level with a basis set including diffuse and polarization functions. Two local minimum geometries are found for each complex. Calculations of the electronically excited states at the CIS level are then used to find the forces on each of the atoms upon vertical excitation to the two lowest-lying (near-degenerate) strongly allowed electronic transitions. These forces are converted to gradients of the excited-state potential surfaces along the ground-state normal modes and compared with the parameters obtained previously from empirical simulations of the experimental resonance Raman intensities of NO3− in dilute aqueous solution. The calculations on two-water clusters agree well with the experimental excited-state geometry changes along the totally symmetric N–O stretch. The calculations underestimate the frequency splitting of the antisymmetric ...

Symmetry breaking effects in NO3−: Raman spectra of nitrate salts and ab initio resonance Raman spectra of nitrate–water complexes

Solid ammonium nitrate (NH 4 NO 3 ) exists in five stable polymorphic forms (designated as phases I, II, III, IV, and V) below its melting point at around 170°C. Phase IV is stable in a temperature range of −17°C ∼ 32°C and is the only phase that has been considered by the atmospheric research community until recently. In this study, we examine the IV ↔ III phase transition of NH 4 NO 3 and how relative humidity (RH) affects the transition path and the transition temperatures using in-situ microscopic Fourier Transform InfraRed spectroscopy. Two kinds of NH 4 NO 3 samples, powder produced from grinding commercially produced chemicals and single particles obtained by efflorescence of droplets on PTFE filters, were studied. The powder samples exhibit the IV↔III phase transition and the transition temperature depends on the RH while the single particle samples exhibit only the IV↔II transition at about 52°C (forward) and 48°C (reverse), bypassing phase III, with transition temperatures independent of the RH....

https://www.tandfonline.com/doi/pdf/10.1080/02786820701272038

H.C. Tang

Papers

Raman study of NH4NO3 and ND4NO3—250–420K

Raman scattering study of the low temperature phase of ammonium nitrate