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Sil S, Kuhar N, Roy K, Chaturvedi D, Morita S, Ozaki Y, Umapathy S. Understanding phase transition and vibrational mode coupling in ammonium nitrate using 2D correlation Raman spectroscopy. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2021; 254:119581. [PMID: 33706114 DOI: 10.1016/j.saa.2021.119581] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/18/2021] [Accepted: 01/30/2021] [Indexed: 06/12/2023]
Abstract
Ammonium nitrate (AN) is an important component of the chemical industry such as an active ingredient in fertilizers, as an oxidizer in explosive compositions and propellants, and as a blasting agent in civil explosives. Numerous accidents have been reported in the past which concerns its thermal instability and poses a big threat to its processing, transportation, and storage. Despite much literature being reported to understand its thermal instability, a mechanistic view remains unclear. In the present work, we have studied the behavior of AN to temperature change using a mathematical approach called 2D correlation (2D Cos) Raman spectroscopy to provide complete insight into the detailed dynamical nature of the interactions between the species (ionic or molecular) occurring with an increase in temperature. We have analyzed various libration and translational modes of nitrate in the low-frequency region using this mathematical tool. It is observed from 2D maps that the phase transition of AN starts with changes in libration modes followed by various nitrate modes and ammonium modes which further precedes low-frequency translational modes. Further, the 2D correlation could differentiate between modes splitting and shifting based on specific 2D Cos pattern. The changes occurring in the N-O deformation modes, symmetric stretching modes as well as anti-symmetric stretching modes which have been attributed to the weakening of the hetero-ionic coupling between the NH4+ and the NO3- ions could be clearly distinguished in the 2D synchronous and asynchronous plots. Besides, moving window analysis was performed to visualize the transition temperature at which phase change of AN takes place.
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Affiliation(s)
- Sanchita Sil
- Defence Bioengineering & Electromedical Laboratory, DRDO, Bangalore 560093, India
| | - Nikki Kuhar
- Department of Inorganic & Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Khokan Roy
- Department of Inorganic & Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Deepika Chaturvedi
- Department of Inorganic & Physical Chemistry, Indian Institute of Science, Bangalore 560012, India
| | - Shigeaki Morita
- Dept. of Engineering Science, Osaka Electro-Communication University, Osaka, Japan
| | - Yukihiro Ozaki
- School of Science and Technology, Kwansei Gakuin University, 2-1 Gakuen, Sanda, Hyogo 669-1337, Japan; Toyota Physical and Chemical Research Institute, 41-1, Yokomichi, Nagakute, Aichi 480-1192, Japan
| | - Siva Umapathy
- Department of Inorganic & Physical Chemistry, Indian Institute of Science, Bangalore 560012, India; Dept. of Instrumentation and Applied Physics, Indian Institute of Science, Bangalore 560012, India.
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Steele BA, Oleynik II. New phase of ammonium nitrate: A monoclinic distortion of AN-IV. J Chem Phys 2016; 143:234705. [PMID: 26696068 DOI: 10.1063/1.4937420] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
A new phase of ammonium nitrate (AN) is found using first principles evolutionary crystal structure search. It is this polymorph that is associated with the phase transition to previously unidentified phase, which was detected in experiment at 17 GPa upon appearance of the two extra peaks in Raman spectrum. The new phase has a monoclinic unit cell in the P21/m space group symmetry (AN-P21/m) and is similar to the known phase IV of AN (AN-IV) except the ammonium molecules are oriented differently relative to the nitrate molecules. The calculated free energy of AN-P21/m is found to be lower than AN-IV at pressures above 10.83 GPa. The equation of state of both AN-P21/m and AN-IV phases (volume vs hydrostatic pressure at room temperature) has been obtained within the quasi-harmonic approximation. The calculated Raman spectrum of both AN-P21/m and AN-IV as a function of pressure is in a good agreement with experiment. The energetic competitiveness of AN-IV and AN-P21/m at ambient conditions suggests a possibility of the phase transition in a small pressure-temperature range near ambient pressure and temperature.
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Affiliation(s)
- Brad A Steele
- Department of Physics, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, USA
| | - Ivan I Oleynik
- Department of Physics, University of South Florida, 4202 East Fowler Avenue, Tampa, Florida 33620, USA
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Chellappa RS, Dattelbaum DM, Velisavljevic N, Sheffield S. The phase diagram of ammonium nitrate. J Chem Phys 2012; 137:064504. [DOI: 10.1063/1.4733330] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Dunuwille M, Davidson AJ, Chellappa RS, Dattelbaum DM, Yoo CS. Pressure induced isostructural metastable phase transition of ammonium nitrate. J Phys Chem A 2011; 115:11889-96. [PMID: 21902257 DOI: 10.1021/jp207754z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The energetic material ammonium nitrate (AN, NH(4)NO(3)) has been studied under both hydrostatic and nonhydrostatic conditions using diamond anvil cells combined with micro-Raman spectroscopy and synchrotron X-ray powder diffraction. The refined powder X-ray data indicates that under hydrostatic conditions AN-IV (orthorhombic, Pmmn) is stable to above 40 GPa. In one nonhydrostatic compression experiment a volume collapse was observed, suggesting an isostructural phase transition to a "metastable" phase IV' between 17 and 28 GPa. The structures of phase IV and IV' are similar with the subtle difference in the hydrogen-bonding network; that is, a noticeably shorter N1···O1 distance seen in phase IV'. This hydrogen bond has a significant component along the b-axis, which proves to be the most compressible until cell axis over the entire pressure range. It is likely that the shear stress of the nonhydrostatic experiment drives the phase IV-to-IV' transition to occur. We compare the present isotherms of phase IV and IV' in both static and nonhydrostatic conditions with the previously obtained Hugoniot and find that the nonhydrostatic isotherm approximately matches the Hugoniot. On the basis of this comparison, we conjecture that a chemical reaction or phase transition may occur in AN under dynamic pressure conditions at 22 GPa.
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Affiliation(s)
- Mihindra Dunuwille
- Institute for Shock Physics and Department of Chemistry, Washington State University, Pullman, Washington 99164-7041, United States
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Schlenker JC, Martin ST. Crystallization Pathways of Sulfate−Nitrate−Ammonium Aerosol Particles. J Phys Chem A 2005; 109:9980-5. [PMID: 16838915 DOI: 10.1021/jp052973x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Crystallization experiments are conducted for aerosol particles composed of aqueous mixtures of (NH(4))(2)SO(4)(aq) and NH(4)NO(3)(aq), (NH(4))(2)SO(4)(aq) and NH(4)HSO(4)(aq), and NH(4)NO(3)(aq) and NH(4)HSO(4)(aq). Depending on the aqueous composition, crystals of (NH(4))(2)SO(4)(s), (NH(4))(3)H(SO(4))(2)(s), NH(4)HSO(4)(s), NH(4)NO(3)(s), 2NH(4)NO(3) x (NH(4))(2)SO(4)(s), and 3NH(4)NO(3) x (NH(4))(2)SO(4)(s) are formed. Although particles of NH(4)NO(3)(aq) and NH(4)HSO(4)(aq) do not crystallize even at 1% relative humidity, additions of 0.05 mol fraction SO(4)(2-)(aq) or NO(3)(-)(aq) ions promote crystallization, respectively. 2NH(4)NO(3) x (NH(4))(2)SO(4)(s) and (NH(4))(3)H(SO(4))(2)(s) appear to serve as good heterogeneous nuclei for NH(4)NO(3)(s) and NH(4)HSO(4)(s), respectively. 2NH(4)NO(3) x (NH(4))(2)SO(4)(s) crystallizes over a greater range of aqueous compositions than 3NH(4)NO(3) x (NH(4))(2)SO(4)(s). An infrared aerosol spectrum is provided for each solid based upon a linear decomposition analysis of the recorded spectra. Small nonzero residuals occur in the analysis because aerosol spectra depend on particle morphology, which changes slightly across the range of compositions studied. In addition, several of the mixed compositions crystallize with residual aqueous water of up to 5% particle mass. We attribute this water content to enclosed water pockets. The results provide further insights into the nonlinear crystallization pathways of sulfate-nitrate-ammonium aerosol particles.
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Affiliation(s)
- Julie C Schlenker
- Division of Engineering and Applied Sciences, Harvard University, Cambridge, Massachusetts 02138, USA
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Schlenker JC, Malinowski A, Martin ST, Hung HM, Rudich Y. Crystals Formed at 293 K by Aqueous Sulfate−Nitrate−Ammonium−Proton Aerosol Particles. J Phys Chem A 2004. [DOI: 10.1021/jp047836z] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Julie C. Schlenker
- Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Pierce Hall, Room 122, Cambridge, Massachusetts 02138
| | - Adam Malinowski
- Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Pierce Hall, Room 122, Cambridge, Massachusetts 02138
| | - Scot T. Martin
- Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Pierce Hall, Room 122, Cambridge, Massachusetts 02138
| | - Hui-Ming Hung
- Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Pierce Hall, Room 122, Cambridge, Massachusetts 02138
| | - Yinon Rudich
- Division of Engineering and Applied Sciences, Harvard University, 29 Oxford Street, Pierce Hall, Room 122, Cambridge, Massachusetts 02138
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Naumov P, Jovanovski G. Vibrational study and spectra-structure correlations in ammonium saccharinate: comparison with the alkali saccharinates. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2000; 56A:1305-1318. [PMID: 10888436 DOI: 10.1016/s1386-1425(99)00229-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The FT IR spectra, at temperatures from liquid-nitrogen boiling (LNT) up to room temperature (RT), as well as the RT Raman solid-state spectra of protonated and deuterated ammonium saccharinate and of a series of alkali (Na, K, Rb, Cs) saccharinates are studied. The spectral assignments are aided with ab initio calculations on the free saccharinato anion at the HF/6-31 + + G(d,p) level. Attention is paid to the ND, CO and SO2 stretching regions. Correlation splitting is believed to be responsible for the presence of a v(CO) doublet. The averaged v(CO) frequency in (purely ionic) ammonium saccharinate is found to be the lowest in the so far studied saccharinates, along with the assumptions that the v(CO) frequency (or the corresponding averaged value) can have predictive value for the type of the metal-to-saccharinato ligand/ion bonding. The appreciably higher contribution of the dominating internal coordinate in the corresponding normal vibration in case of v(as)(SO2) than in v(s)(SO2) makes it suitable for spectra-structure correlations. Contrary to RT, even though no phase transitions were observed in the studied temperature range, some polycentered character is prescribed to the hydrogen bonds in which the ammonium ions of effective symmetry C8 participate at LNT. Certain structural predictions about the saccharinates of K, Rb and Cs are made.
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Affiliation(s)
- P Naumov
- Institute of Chemistry, Faculty of Sciences, Sv. Kiril i Metodij University, Skopje, Macedonia.
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The vibrations of bridging carbonyl groups as more sensitive indicators of molecular geometry than terminal carbonyl groups in transition metal carbonyl cluster compounds. Inorganica Chim Acta 1994. [DOI: 10.1016/0020-1693(94)04216-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Tomkinson J, Kearley GJ. Phonon wings in inelastic neutron scattering spectroscopy: The harmonic approximation. J Chem Phys 1989. [DOI: 10.1063/1.457615] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jayasooriya UA, Kettle SFA, Lugwisha E. Intermolecular vibrational coupling associated with the 2ν2 features of the Raman spectrum of strontium nitrate. J Chem Phys 1987. [DOI: 10.1063/1.453533] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Solid-state studies. Part XXIV: Raman spectral consequences of disorder in the structure of phase II of ammonium nitrate. ACTA ACUST UNITED AC 1982. [DOI: 10.1007/bf01161008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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