Ind. Eng. Chem. Prod. Res. Dev. 1985, 24, 440-442
440
Merrill, R. M. Sandia Laboratories Report SAND79-0653, Dec 1980, Albuquerque, NM. Schumacher, R. J.; Bullock, K. Mound Facllity Report MLM-3121, November 1983. Schumacher, R. J.; Brown, N. E.; Deutsch. E. Mound Facility Report to be published in 1985. Searcy, J. Q.: Shanahan, K. L. Sandia Laboratories Report SAND78-0466, Aug 1978, Albuquerque, NM.
Yelton, R. 0.; Lieberman, M. L.; Andrzejewski. W. J. presented at the XXIII International Conference on Coordinatlon Chemistry, Boulder, CO, 1984.
Received for review February 1, 1985 Revised manuscript received April 2, 1985 Accepted May 10, 1985
Fundamental Research on Explosives Program Thomas Rivera Explosives Technology, MS C920, Los Alamos National Laboratory, Los Alamos, New Mexico 87545
The Fundamental Research on Explosives (FRE) program is a multidisciplinary, Laboratory-wide fundamental research effort whose aim is to gain a detailed molecular-level understanding of the energetics of liquid nitric oxide decomposition that supports the phenomenon of detonation in that system. In the FRE program we are interested in the details of the acquisition and maintenance of steady detonation in liquid nitric oxide and in how this steady condition compares to the existing (Chapman-Jouguet) theory of steady detonation.
Introduction The Fundamental Research on Explosives (FRE) program was initiated as a 5-year program beginning in fiscal year 1982. It was established as a Laboratory-wide, coordinated theoretical and experimental effort aimed at gaining a fundamental understanding of detonation behavior using state-of-the-art techniques not previously applied to explosives. The program represents a new approach in our efforts to understand the fundamental processes of detonation. Initial tasks included choosing a prototype explosive molecule simple enough to allow study of the details of the detonation process both experimentally and theoretically. Liquid nitric oxide (NO) was selected. Subsequently, a plan of attack evolved that established the following goals: (1)determine the equation-of-state (EOS) properties of liquid NO, (2) explore the chemistry of initiating and detonating liquid NO, and (3) measure detonation properties of liquid NO with sufficient precision to enable a test of current Chapman-Jouguet (CJ) theory. A list of fiscal year 1984-participating FRE team members is presented in Table I. Overview A. Detonation Products EOS. The experimental portion of the work on the EOS of the detonation products of liquid NO has been successfully completed (Schott et al., 1985). The experimental data, which was obtained in the pressure range of 10-30 GPa, are compared with theoretical Hugoniot curves in Figure 1. Our newly developed method (Johnson et al., 1984;Shaw et al., 1983) for treating nonspherical potentials of molecular fluids using effective spherical potentials coupled with existing mixing rules was utilized in modeling the EOS. Intermolecular potentials were calculated by using ab initio (Hay et al., 1984) and semiempirical methods (Pack, 1984). The agreement between experimental data and theoretical calculations is excellent. The resulting EOS is adequate for our planned test of CJ theory, but the question of what forms of oxidized nitrogen are actually present as products of detonating NO remains to be answered. B. Shock Wave Measurements. We have experimentally verified the attainment of chemical equilibrium 0196-4321/85/ 1224-O440$Q1.50/0
Table I. FRE Team Members, Fiscal Year 1984 name category contributing activity S. F. Agnew spectroscopy spectroscopy of molecules at high density N. C. Blais spectroscopy studies of clusters of explosive molecules J. B. Cross spectroscopy intermolecular forces W. C. Davis" hydrodynamics detonation physics W. Fickett technical advisor, detonation TACb physics N. R. Greiner spectroscopy detonation products' chemistry P. J. Hay theory ab initio intermolecular potentials B. L. Holian TACb technical advisor, theory J. D. Johnson theory thermodynamics of dense molecular fluids R. L. Mills" hydrodynamics unreacted NO EOS D. S. Moore laser-based diagnostics of spectroscopy shocked materials N. S. Nogar spectroscopy spectroscopy of highly excited molecules semiempirical intermolecular R. T. Pack" theory potentials T. Rivera project manager coordination of research program R. N. Rogers0 consultant explosives' chemistry R. R. Ryan TACb technical advisor, spectroscopy S. C. Schmidt hydrodynamics laser-based diagnostics of shocked material D. Schiferl spectroscopy of molecules at spectroscopy high density B. I. Schneider theory intermolecular potentials G. L. Schott hydrodynamics shocked-state measurements L. A. Schwalbe hydrodynamics unreactsd NO EOS M. S. Shaw theory thermodynamics of dense molecular fluids J. R. Stine theory theoretical chemical dynamics B. I. Swanson spectroscopy spectroscopy of molecules at high density J. J. Valentini spectroscopy spectroscopy of highly excited molecules Los Alamos Fellow.
Technical Advisory Committee.
in detonating liquid NO. We were able to do this because the same thermodynamic state is reached by shocking either liquid NO or liquid N2 + O2mixtures to -21 GPa (Schott, 1984). At lower shock pressures, -3 GPa, we found that the reactions leading to detonation are ap0 1985 American Chemical Society
Ind. Eng. Chem. Prod. Res. Dev., Vol. 24, No. 3, 1985 441
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parently slow enough to be studied on a time scale of 1 ps (Figure 2). These pressures and their associated velocities are conditions achievable with the gas guns we plan to use in future experiments. Subsequent investigations on the shock-initiation regime of liquid NO will include the implementation of laser-interferometric techniques to continuously track motions of the shock and driving interface. C. Spectroscopic Diagnostics of Shocked Molecules. We have developed spectroscopic techniques for the diagnostics of shock-compressed materials. The techniques include (1)backward-stimulated Raman scattering (BSRS) (Schmidt et al., 1983) and (2) reflected broadband, coherent anti-Stokes Raman scattering (RBBCARS) (Moore et al., 1983). The BSRS technqiue has been used to measure the frequency shift of the vibrational ring-stretching mode of benzene, shock-compressed to pressures of 0.6-1.2 GPa. The RBBCARS method was used to measure the "ring-breathing" vibrational frequencies of neat liquid benzene, neat liquid deuterated benzene (benzene-d,), and mixtures of these under shock compression to pressures up to 1.53 GPa. Figure 3 is a schematic representation of the RBBCARS experiment. Future spectroscopic investigations on the shock-initiation regime of liquid NO will utilize the RBBCARS technique in an attempt to identify chemical species.
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D. High-Pressure-Induced Chemistry of NO. Thus far, attempts to observe NO at high static pressures in diamond-anvil cells have revealed a condensed-phase chemistry of NO having a high degree of complexity that includes evidence for ionic species, isomerizations, radicals, and disproportionation (Agnew et al., 1983, 1985). We have conducted laboratory-scale studies of the detonation products of condensed NO (Greiner, 1985). The products found in these studies apparently come from at least two different reaction sources: (1)those characteristic of pressure-induced disproportionation as observed in diamond-anvil cells and (2) those predicted as being sole detonation products by means of calculations based on ideal detonation theory. These experiments were performed in a vacuum chamber fitted with a cryogenically cooled detonating device designed to detonate solid NO condensed from a gas stream onto a surface cooled to 15
442
Ind. Eng. Chem. Prod. Res. Dev. 1085, 24, 442-447
K. Figure 4 depicts the cryotip and shock mount. The slapper and booster used to initiate detonation are shown in Figure 5. We are proceeding to characterize the reactions and to verify the extent to which true detonation was achieved. E. Detonation-Velocity Measurements. We have measured the detonation velocity of liquid NO in graphite tubes at 115 K as a function of charge diameter (Davis, 1985). The failure diameter was found to be 8 mm, with the corresponding velocity near failure being 5160 m/s. The infinite-diameter velocity was found to be 5622 m/s. We are modifying our apparatus for measurements of detonation pressure and wave shape. Pressure will be determined by measuring the velocity of metal plates driven by the explosive and wave shape by streak-camera records of the deflection of a mirrored surface by the detonation front. F. Chemical Dynamics. We have studied the lowdensity (gas-phase) chemical dynamics of NO decomposition reactions. Our spectroscopic investigations (Blais, 1985) into a molecular chain mechanism for NO detonation proposed by Valentini et al. (1983) have confirmed our earlier notions that we cannot rely solely on experience and intuition gained from low-density gas-phase kinetics studies. Theoretical investigations into possible gas-phase reaction mechanisms have also been made by Stine and Noid (1983). Currently under study are the initiation and mechanism in the detonation of condensed-phase NO (Stine, 1984). We seek to gain insight into the influence of such effects as cage, many-body, and quantum effects on hypothetical mechanisms. A valence bond type of potential energy surface that allows a cluster of (NO), to dissociate into possible neutral subspecies is under development. Conclusions The Fundamental Research on Explosives Program seeks the fundamental knowledge of why and how chemical
changes take place in a detonating high explosive. We have demonstrated that a coordinated effort involving theory and experiment, reaching across scientific disciplines, is useful in attaining this knowledge. The advances achieved as a result of this program present avenues for innovation and further progress in the understanding of the fundamentals of high explosives utilization.
Acknowledgment This work is supported by Institutional Supporting Research and Development funds provided by the Los Alamos National Laboratory of the University of California under the auspices of the Department of Energy, Contract W-7405-ENG-36. Registry No. NO, 10102-43-9.
Literature Cited Agnew, S. F.; Swanson, 9.I.; Jones, L. H.; Mills, R . L.; Schiferl, D. J. fhys. Chem. 1983, 87, 5065. Agnew, S. F.; Swanson, B. I.; Jones, L. H.; Mills, R. L. J. Phys. Chem. 1985, 89, 1678. Blais, N. C. J. Phys. Chem., in press. Davis, W. C. Roc. Symp. Detonation 8th, in press. Greiner, N. R. Proc. Symp . Detonation Bth, in press. Hay, P. J.; Pack, R. T.; Martin, R. L. J. Chem. fhys. 1984, 8 1 , 1360. Johnson, J. D.; Shaw, M. S.; Holiin, B. L. J. Chem. Phys. 1984, 80, 1279. Moore. D. S.; Schmidt, S. C.; Shaner, J. W. fhys. Rev. Lett. 1983, 5 0 , 1819. Pack, R. T., Los Alamos National Laboratory, 1984, unpublished data. Schmidt, S. C.; Moore, D. S.; Schiferl, D.; Shaner. J. W. fhvs. Rev. Lett. 1983, 50, 661. Schott, G. L. in "Shock Waves in Condensed Matter-1983"; North-Holland: Amsterdam, 1984; p 49. Schott, G. L.; Shaw, M. S.; Johnson, J. D. J. Chem. Phys. 1985, 82, 4264. Shaw, M. S.; Johnson, J. D.; Holian, B. L. Phys. Rev. Lett. 1983, 50, 1141. Stine, J. R., Los Alamos National Laboratory, private communication, 1984. Stine, J. R., Noid, D. W. J. Phys. Chem. 1983, 8 7 , 3038. Stine, J. R., Noid, D. W. Chem. Phys. Lett. 1983, 100, 282. Stine, J. R., Noid, D. W. J. Chem. Phys. 1983, 78, 1876. Stine, J. R., Noid, D. W. J. Chem. fhys. 1983, 78, 3647. Vaientlni, J. J.; Nogar, N. S.; Breshears, W. D., Los Alamos National Laboratory, 1983, unpublished data.
Received for review January 22, 1985 Accepted May 10, 1985
Chemiluminescence in Autoxidation of Hydrocarbons. A Method for Fingerprinting and Evaluation of Oxidative Stability Ilgvarr J. Spilners' and John
F. Hedenburg
Gulf Research & Development Company, Pktsburgh, Pennsylvania 15230
Chemiluminescence (CL) was generated when mineral oils, lubricants, and synthetic hydrocarbons were autoxidized at elevated temperature. CL intensity measurements were useful as a rapid method for evaluation of relative oxidative stabilities, and CL spectra served to differentiate and fingerprint hydrocarbon materials. Mineral oils which had been more severely refined to achieve a hlgher oxidative stability gave lower CL intensity. CL spectra and spectral changes with tlme were useful to differentiate oils according to their crude sources. CL measurements required less tlme than the conventionaloxklatbn tests and a good agreement with A S N D943 oxidation test could be shown. CL was also useful in monitoring and assessing service life left in used lubricants.
Introduction Chemiluminescence (CL)is emitted in the first steps of autoxidation when peroxide radicals or radicals formed during the decomposition of hydroperoxides recombine
* Ilgvars J. Spiinen, 119 Alleyne Drive, Pittsburgh, PA
15215.
0198-4321/85/1224-0442$01.50/0
(Vasilev and Vichutinski, 1962a; Vasilev et al., 1959). By use of the basic autoxidation scheme (Reich and Stivala, 19691, the following interpretation of the reaction steps can be made for the conditions used. The hydrocarbon was heated first under nitrogen at 180 to 250 OC. Under these conditions, any residual peroxides which might have been present were decomposed and some 0 1985 American
Chemical Society
