Back to Dr. Jan A. Puszynski (and others involved with the same work):
http://www.ematerials.org/2007Meeting_call_for_papers.htmlEMG Annual Meeting
Registration & Program
AIChE EMG Annual Meeting
November 4-9, 2007
Salt Lake City, UT
The EMG Annual Meeting (held at the AIChE Annual Meeting) registration is now open. Please visit the AIChE Annual Meeting to register.
Each EMG Session will include a minimum of one of the following papers/presentations:
-the state of the research and technology in a specific area,
or
- a tutorial on an EMG topic.
To encourage high quality papers and presentations, two awards will be made in partnership with EMG and the PTF:
- Best EMG Presentation
- Best EMG Paper to be sent to the PTF at lease 60 days (September 6, 2007) prior to the Annual Meeting, suitable for publication, (more information later) e.g. Energetic Materials.
If you have any questions please contact one of the session chairs or Bruce Cranford,
Bruce-Cranford-PE@Comcast.net Schedule
Sunday November 4, 2007;
- PTF - Executive Committee Meeting, Time: 5:00 PM - 6:30 PM
Monday November 5, 2007;
- PTF - General Body Meeting, Time: 6:00 PM - 7:00 PM
Wednesday November 7, 2007;
- Particle Technology Forum Dinner,
Time: 6:30 – 7:30 pm, reception.
7:30 – 10:00, dinner and awards presentation
Location: Abravanel Hall, 123 S.
West Temple,Salt Lake City
Dinner: Ticket: $65 per person
ATK Tour Arranged by Charles Painter, NSWC, and Scott Lusk, ATK
Thursday November 8, 2007;
- EMG Business Meeting, time and location Programming Meeting 11:00 AM 12:00 PM, G. Ballroom F (Main Floor)
EMG Business Meeting, Minutes 11/8
(Action Items in Blue)
- AIChE wants to put more focus on Energy. There may be some opportunities to carry out joint sessions with other groups.
- C. Clark will be the co-chair of the Energetics Processing and Safety sessions, replacing J. Salan.
- A decision has to be taken to fill the Vice President position.
- EMG Alan Weimer or Manuk Colakyan focus PTF on energy, Bruce Cranford to assist.
- AIChE said more sessions are available at the 2008 Annual Meeting, which will be longer 11/12 to 11/21/2008.
- The Philadelphia meeting is the centennial meeting of the AICHE and the history and accomplishments of AICHE will be documented.
- The EMG will also make an effort to document the major accomplishments of energetics research in the US , parallel to the efforts o AICHE. Clark knows a person who has done significant historical research in this area and will pursue.
- - Add paper(s) on the history of Energetic Materials (Clark).
- 8th World Congress on Chemical Engineering will be held in Montréal, Canada , on 8/2009. EMG will try for 1 session. Cranford/Puszynski
- EMG annual meeting 11/2008 call for papers will be 1/15/2008 to 5/14/2008.(Cranford, Painter, Kalyon, Cushman, Puszynski, Clark, Boddu)
- PTF will add the Best Paper Award, starting in 2007. It will be composed of 2 parts, Best Presentation (Based upon EMG Criteria) plus Best Paper (Criteria to be developed). In order to qualify, Authors must submit an extended abstract of 6 pages plus present the paper. Each Group 3A through 3E will select a winner at the end of their respective sessions. The winners will be presented a plaque at the following years PTF award banquet. (Cranford, Painter, Kalyon, Cushman, Puszynski, Clark, Boddu).
- Kalyon will provide a modified version of the foreword written to Journal of Energetic Materials to introduce the special issues dedicated to the memory of Dr. Richard S. Miller for the web site with a listing of the papers that have appeared.
- EMG will encourage the submission of full proceedings papers to the AICHE meeting, followed by their submission to a journal like Journal of Energetic Materials.
- This year, the 3E best presentation will be announced shortly after the end of the 2007 annual meeting and a plaque awarded to the EMG winner, in addition to the above PTF plaque. ( Cranford, Puszynski)
- Contact Shrikant with 3E best Presentation/paper award, ( Cranford.)
- Order Plaque, ( Cranford)
- Present 2006 award winner a plaque (Kalyon)
- Next World Particle Technology Conference will be held in Nürnberg, Germany , 11-15 April 2010. EMG to try for a session.( Cranford)
- Met with Boyd Hill from ATK about getting ATK more involved with EMG. Had wide ranging discussions on how mutual interaction could benefit both. Suggested ATK sponsor an annual award on Energetics, similar to PTF Shell/Dow, etc at the Annual PTF Awards Dinner. Also suggested making employment announcements on the EMG web site. Boyd will bring to the attention of ATK.(Clark, Cranford)
- Encourage more poster participation.(Cranford, Painter, Kalyon, Cushman, Puszynski, Clark, Boddu)
- Expand 2008 EMG conference to 4 session plus a business meeting. The 4th session would be on Thermophysical Properties, chaired byVerra Boddu.
- Requested short 1-2 paragraphs addressed to the EMG from (Kalyon, Puszynski, Cranford, Painter) to be sent to the members and posted on the web site, several times a year.
- Requested summaries of each 2007 session from the session chairs, (Kalyon, Puszynski, and Cushman), to be posted on the web site.
- Elections will be held in the summer of 2008 for new officers. ( Cranford)
- Thank you letters sent to EMG speakers employers if they request one. (Painter, Cranford)
[Insert: See original site for graph, excerpted specific part here:
Nano-Energetic Materials (co-sponsored 3d)
- Puszynski
- Bruce Cranford
- EMG three technical sessions.
544 Nano-Energetic Materials 03E00
8:30 AM to 11:00 AM
M - Salon F (Marriott Salt Lake City-Downtown)
- Chair: Jan A. Puszynski, Professor, Chemical and Biological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701, Phone Number: 605-394-1230, Fax Number: 605-394-1232, Email:
Jan.Puszynski@sdsmt.edu- Co-Chair: Bruce Cranford, P.E., Dept. EMF, 1 Cliffe Hill Ct., Potomac, MD 20854. 301-873-9087,
Bruce-Cranford-PE@comcast.netThis session aims to encompass research in the area of the formation of reactive nanoparticles and their application in energetic systems. Contributions are solicited addressing both experimental and theoretical aspects of reaction kinetics, processing, and characterization of energetic materials involving nanoreactants.
CoSponsor(s): Nanoparticles (03d)
8:30 AM
544a Advanced Materials And Nano-Energetic Development At Us Army, Rdecom-Ardec
Paul Redner, Energetics, Warheads and Environmental Technology Division, US Army, RDECOM-ARDEC, Bldg 3022, AMSRD-AAR-AEE-W, Picatinny, NJ 07806-5000
The US Army, at RDECOM-ARDEC, has been exploring various technologies to produce both energetic and non-energetic nanomaterials and advanced materials. ARDEC has established partnerships with industry and academia to synthesize and modify materials to meet identified needs and technology gaps as identified by DoD and Army leadership. These technologies are either being developed at ARDEC or will be transferred to the ARDEC campus so that a wide array of prototyping capabilities will be available to transition these technologies to core programs.
This briefing will discuss the various partnerships and technologies ARDEC is developing. It will bring to light the progress that has been made over the past few years as well as the challenges that have been overcome and the ones that the Army still faces as these materials and technologies are transferred to the Warfighter.
9:10 AM
544b Heterogeneous Mixtures of Boron Compounds with Metals and Water for Hydrogen Generation
Moiz Diwan, Victor Diakov, Evgeny Shafirovich, and Arvind Varma. School of Chemical Engineering, Purdue University, 480 Stadium Mall Drive, West Lafayette, IN 47907
Sodium borohydride (SBH) and ammonia borane (AB) are promising hydrogen-storing compounds to feed fuel cells for portable electronic devices. To release hydrogen from these compounds, pyrotechnic mixtures of SBH and AB with solid oxidizers were considered by previous researchers. Alternatively, Hydrolysis of these compounds has also been studied extensively. To obtain high hydrogen yield without any adverse environmental effects, we use heterogeneous mixtures of SBH or AB with gelled water and nanoaluminum or magnesium.
Due to the highly exothermic metal-water reaction, such mixtures, upon ignition, exhibit self-sustained propagation of combustion wave with simultaneous release of hydrogen from the boron compounds and water. Mechanistic studies of this process were conducted using digital video recording, pressure monitoring, thermocouple measurements, gas chromatography, mass spectrometry, TGA, and powder XRD analysis. Isotopic tests using D2O were performed to characterize roles of thermolysis and hydrolysis.
9:35 AM
544c Fully Dense Aluminum Rich Al-Cuo Nanocomposites for Energetic Formulations
Demitrios Stamatis1, Vern K. Hoffmann1, Mirko Schoenitz1, and Edward L. Dreizin2. (1) Mechanical Engineering, New Jersey Institute of Technology, Newark, NJ 07102, (2) Chemical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102
The thermite reaction between Al and CuO is well known and highly exothermic. For a conventional thermite mixture comprising mixed metal and oxide powders, this reaction is rate limited by the slow heterogeneous mass transfer at the metal and oxide interface. The relatively low reaction rate and a difficult ignition have restricted practical applications for this reaction. For newly developed, nano-composed thermites, the interface area can be substantially increased resulting in a much higher reaction rate and a new range of possible applications.
Recently, magnetron sputtering was used to create Al-CuO nanofoils for applications in joining. Nanocomposite Al-CuO compositions for pyrotechnics were also prepared using mixture or a self-assembling array of respective nanopowders. Such techniques realize the bottom-up approach, when the nanostructures or nanoparticles are built from individual atoms or molecules. Respective materials are generally expensive and difficult to handle. An alternative, top-down approach is discussed in this project.
Nanocomposite Al-CuO materials are produced using a technique referred to as arrested reactive milling. Regular metal and oxide powders are blended and ball milled at room temperature resulting in a fully dense and reactive nanocomposite powder. The milling is stopped (or arrested) before a self-sustaining exothermic reaction is triggered. The powder particles are the 10-100 µm size range. Each particle has an aluminum matrix with copper oxide inclusions in the 20-200 nm size range, depending on milling parameters.
The produced Al-CuO nanocomposite powders have been considered for applications in propellants, explosives, pyrotechnics, as well as for joining small parts. In accordance to the application requirements, the powder composition and morphology can be modified to optimize performance. Aluminum-rich compositions are of particular interest for novel energetic components. Synthesis methodology, material properties as a function of composition and morphology, and performance tests will be discussed in this paper.
9:55 AM
544d Modeling Of Reduction-Oxidation Reactions In Al-MoO3 Nanocomposite Powders
Mikhaylo A. Trunov, Mirko Schoenitz, and Edward L. Dreizin. Chemical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102
Recently, reactive Al-MoO3 nanocomposites were prepared by arrested reactive milling for potential applications in various energetic formulations, including pyrotechnics, explosives, and propellants. Other manufacturing approaches, including nanopowders mixing and sol-gel processing have also been recently explored to produce similar nanocomposite thermite compositions. The reactions in nanocomposite powders were investigated by differential scanning calorimetry and correlated with their ignition kinetics quantified from heated filament ignition experiments.
It was observed that many overlapping processes control the reaction rate and ignition so that a simplified model based on several independent processes is inadequate for practically useful predictions. The objective of this work is to develop a model of oxidation processes in the Al-MoO3 nanocomposites that enables one to describe the experimental data and account for differences in ignition kinetics as a function of the scale and morphology (e.g., spherical vs. flat) of nano-domains. The model describes the reduction of two oxide phases, MoO3 and MoO2.
Oxygen ions produced as a result of molybdenum oxide reduction diffuse to aluminum through a growing aluminum oxide layer. The model accounts for simultaneous growth of different aluminum oxide polymorphs and for polymorphic phase transformations occurring within the aluminum oxide layer. This modeling approach was previously successfully used to describe oxidation and ignition of aluminum particles in air.
Compared to the model of Al oxidation in air, the Al-MoO3 nanocomposite reaction model includes new assumptions about diffusion characteristics of growing alumina polymorphs films sandwiched between molybdenum oxides and aluminum. Most of the kinetic parameters describing specific reactions are determined from processing the scanning calorimetry and ignition experiments. The model formulation and results will be presented and compared to experimental data. Phase analysis of quenched samples is planned to verify the model predictions about the phases formed at different stages of the reduction-oxidation reactions.
10:15 AM
544e Esd Sensitivity Of Nanoenergetics Produced By Water Processing Method
Chris J. Bulian, Jan Puszynski, and Jacek J. Swiatkiewicz. Chemical and Biological Engineering, South Dakota School of Mines and Technology, 501 E. St. Joseph Street, Rapid City, SD 57701
Nanoenergetic materials are a class of materials that have been of much interest for over ten years now. Variation in methods of synthesis and processing have allowed for these materials to be tailored to many different applications (e.g., percussion primers, electric matches, low energy ignition devices, etc.). These applications require wide ranges of reactive energy outputs, reaction rates, and ignition sensitivities.
Appropriate characterization methods have been developed for mechanical impact, thermal, and electrostatic discharge sensitivities. This study presents an explanation of ignition delay times of Al-Fe2O3, Al-MoO3, and Al-Bi2O3 nanoenergetic mixtures during exposure to a laser pulse as a function of a sample density and laser power. It was shown that the porosity of the energetic material significantly affects the ignition delay time due to the dependence of thermal properties as the function of that parameter.
The effect of porosity on ignition delay was also investigated using a mathematical modeling. The model verified that an increase in porosity significantly decreases ignition delay time due to a much lower thermal conductivity and heat capacity of the sample. Electrostatic discharge sensitivity of the nanoenergetic materials was also investigated. This study determined that individual particle size and its morphology (both fuel and oxidizer), degree of consolidation, and processing methods can all have a significant affect on the sensitivity of the nanoenergetic materials to ignition by ESD.
10:35 AM
544f Characterization Of Shock Waves Produced By Nanothermites
Steve Apperson1, Andrey Bezmelnitsyn1, Rajagopalan Thiruvengadathan1, Dan Tappmeyer1, Zhen Chen1, Keshab Gangopadhyay,1, Shubhra Gangopadhyay1, Paul Redner2, Wendy Balas2, Deepak Kapoor2, and Steven Nicolich2. (1) University of Missouri Columbia, Columbia, MO 65211, (2) US Army ARDEC, Picatinny, NJ 07806
A bench-scale shock tube apparatus has been employed to measure the velocity and intensity of pressure waves produced by the combustion of nanothermite materials, synthesized in our laboratory. The combustion wave speed of these novel materials ranges from 1500 m/s to 2400 m/s for a combination of CuO nanorod and nano-Aluminum with optimized sizes and a proper equivalence ratio. The highest speed is achieved by the process of self-assembly between the fuel and oxidizer.
The lowest speed corresponds to simple physical mixture of oxidizer and fuel. In both cases, we observed generation of shockwaves, the strongest one resulting in the self-assembled case. Small quantities of nanothermites (10-200mg) were loaded into a cylindrical volume, and placed against an air-filled tube. Pressure transducers were mounted along the length of the tube to record pressure profiles at various positions. Using time-of-arrival analysis the velocity of the pressure wave was calculated.
Mach numbers ranging from 1.1-3.5 were measured for various compositions of CuO-Al nanothermite. This system has been used to study the effect of nanothermite mass on the shock waves and compare different variations of nanothermite composites. This technique allows rapid testing for tuning of nanothermite compositions for shock wave applications in the defense, energy and biomedical fields.
10:55 AM
544g Reactivity of Conventional and Modified Nanothermites
Andrey Bezmelnitsyn1, Rajagopalan Thiruvengadathan1, Steve Apperson1, Rajesh Shende1, Keshab Gangopadhyay1, Shubhra Gangopadhyay1, Paul Redner2, Wendy Balas2, Deepak Kapoor2, and Steven Nicolich2. (1) University of Missouri Columbia, Columbia, MO 65211, (2) US Army ARDEC, Picatinny, NJ 07806
Nanoengineered composites of metal oxide (oxidizer) and metal(fuel)have shown to exhibit enhanced combustion properties. More specifically, when the sizes of oxidizer and fuel particles are in nanoscale, the heat and the mass transport length scales are drastically reduced, leading to enhanced combustion speeds and reaction rates. Thus, it is quite possible to achieve tunable reaction rates by proper choice and combination of fuel, oxidizer and other chemicals, their dimensions in nanoscale and the mixing ratio. The present work is devoted to the study of reaction rates of conventional and modified nanothermites.
We have used a variety of metal oxides, namely, Fe2O3, CuO and MoO3 and Al as the fuel. The conventional nanothermites were also modified by mixing with ammonium nitrate (AN) nanoparticles. The reactivity was determined by monitoring the pressure as a function of time generated during the energetic reaction. The rate of increase in the pressure generated during combustion process is a measure of the reactivity of the material system. Reactivity rate tests were performed in a closed volume using a typical mass of 20 mg in a milli-well with a packing density of 0.33g/cm3.
Among the conventional nanothermites studied in this work, CuO-Al system possesses the highest reactivity. The rate of pressure increase is about 3.23MPa/µs and the peak pressure recorded is 40MPa. In comparison, it is 0.01MPa/µs for Fe2O3/Al nanocomposite. The reactivity of self-assembled CuO nanorod (NR) - Al nanoparticle composite (3.81 MPa/µs) is higher than that of the one prepared by random mixing of CuO NR and Al nanoparticle (3.23MPa/µs).
The CuO NR – Al based conventional nanothermites were modified by mixing with low-grade explosives, such as ammonium nitrate (AN) nanoparticles. These nanoparticles were prepared by employing microemulsion route. The reactivity increases to about 250 MPa/µs and the peak pressure to 600 MPa for the modified thermite composition with 60 % AN nanoparticles. Mixing of micron size AN particles reduced the reactivity drastically. Our studies clearly show that nanoscale mixing of thermites with explosives is necessary to enhance the reactivity of the mixture.
11:15 AM
544h Reduced Electrostatic Discharge Sensitivity Of Nanothermites
Rajagopalan Thiruvengadathan1, Steve Apperson1, Andrey Bezmelnitsyn1, Keshab Gangopadhyay1, Shubhra Gangopadhyay1, Paul Redner2, Wendy Balas2, Deepak Kapoor2, and Steven Nicolich2. (1) University of Missouri Columbia, Columbia, MO 65211, (2) US Army ARDEC, Picatinny, NJ 07806
Nanoenergetic materials with very high combustion speeds are ideal for use as green primers, kinetic rods, and reactive materials. However, their high sensitivity to ESD remains a major challenge for practical applications. These static sensitive materials may cause accidental ignition posing a major safety hazard. It is known that Al nanoparticles are typically used as the fuel component along with nano-sized metal oxides as oxidizers to prepare nanothermites. These Al nanoparticles are highly sensitive to the ESD, thereby making nanothermites vulnerable to ignition at extremely very low ESD energy.
We explore the possibility of reducing the ESD sensitivity of Al nanoparticles through coating with fluoropolymers such as Teflon. Teflon being an energetic fluoropolymer is expected to sustain the reactivity of nanothermite while helping to reduce the ESD sensitivity. Well dispersed Al nanoparticles in Teflon were obtained by coating the surface of Al nanoparticles first with perfluorooctal mono-functional trimethoxy silane and then with teflon AF solution. Our measurements show that uncoated Al nanoparticles have a very low ESD energy of 0.98mJ.
On the other hand, Al nanoparticles coated with 1 and 2 % of teflon have ESD energy 2.6 mJ and 4.7 mJ respectively. With increasing teflon weight to 4% and 10 %, the ESD energy increases to 25 mJ and 60mJ respectively. We have also studied the combustion properties and reactivity of the Teflon coated nanoparticles with copper oxide nanorods. Although there is a reduction in the burn rate due to Teflon coating, the peak pressure and reactivity of the material increases with the increase in percent of Teflon coating. In conclusion, our results clearly demonstrate that coating with fluoropolymers is very effective in reducing the ESD sensitivity of nanothermite materials.
11:35 AM
544i Nanoparticulation Of CL20: A Feasibility Study To Produce Nanoparticles Of CL20 With Supercritical Fluids
Veera Boddu, Environmental Processes Branch, US Army Engineer Research and Development Center, 2902 Newmark Drive, PO Box 9005, Champaign, IL 61822, Rebecca K. Toghiani, Chemical Engineering, Dave C. Swalm School of Chemical Engineering, Mississippi State University, 330 Swalm, Mississippi State, MS 39762, and Reddy Damavarapu, Energetics and Warheads Division, U.S. Army - Armament Research, Development and Engineering Center, Picatinny Arsenal, NJ.
The Army is interested in developing green processes to support its industrial operations. Developing processes without the use of toxic solvents and chemicals is a major focus of the effort in developing the green processes. This presentation summarizes a recent study to develop nanoparticles of CL20 (2,4,6,8,10,12-Hexanitro-2,4,5,8,10,12-hexaazaisowurtzitane) using supercritical processes. In order to generate the desired nanocrystalline particles, the crude CL20 is dissolved into an environmentally benign solvent such as supercritical carbon dioxide and then condensed to ultrafine particles by reducing the pressure and temperature of the mixture.
It is desired to have at least have estimates of supercritical solubility of CL20 in carbon dioxide, prior to the nanoparticulation experiments. Estimation of solubility of CL20 in supercritical carbon dioxide was carried out using the Peng-Robinson cubic equation of state. Solubility was predicted over the temperature range of 305.15 to 368.15 K and over the pressure range of 74 to 150 atm. In general, as the temperature increases, the solubility decreases, while as the pressure increases, the solubility increases.
For CL20, the estimated vapor pressures are extremely small, on the order of 10-18 at ambient temperature, increasing to 10-13 at 368.15 K. Thus, the predicted solubilities are also small (range of 10-13 to 10-6), with the highest solubility predicted for 308.15 K (35„aC) and 150 atm. Nanoparticulation experiments were conducted using a supercritical extraction apparatus supplied by Thar Technologies, Inc. Results of CL20 solubility predictions and SEM and XRD characterization of the nanoparticles will be presented.
11:55 AM
544j Classification Of Nanopowders In An Ultracentrifuge
Zachary Doorenbos1, Jan Puszynski1, Deepak Kapoor2, and Darold Martin2. (1) South Dakota School of Mines and Technology, 501 East Saint Joseph Street, Rapid City, SD 57701, (2) Armament Research, Development and Engineering Center, Picatinny, NJ 07806
In many energetic and structural applications a narrow particle size distribution is frequently desired to control specific properties such as ignition delay and propagation velocity of the combustion front. However, up to now most size classification techniques available require that the material be in an aerosol form. These classification methods have very low throughputs. Our newly developed size classification technique for nanopowders is based on interfacial particle transport between two immiscible liquids using ultracentrifugal forces.
This wet classification process allows for both batch and continuous flow size fractionation of a slurry consisting of nanopowders. The key parameters that effect the separation efficiency are: type of liquids, use of dispersants in the initial slurry, initial deagglomeration of the particles, ultracentrifuge speed and run time, and the initial particle loading of the slurry. The up to date results show that the use of the two liquid classification system allows for the classification of the nano-materials based on their particle size. This classification system will also be modeled using computational fluid dynamic FLUENT software. The modeling of this system will allow for the prediction of the centrifuge speed and run time that will be needed for the desired fractionation of the initial slurry. The classification results for different nano-material systems will be presented.
604 Processing and Safety 03E01
12:30 PM to 3:00 PM
M - Salon F (Marriott Salt Lake City-Downtown)
- Chair: Dilhan M. Kalyon, Director, Highly Filled Materials Institute, Stevens Institute of Technology, Castle Point Station, Hoboken, NJ 07030, Phone Number: (201) 216-8225, Fax Number: (201) 692-3942, Email:
dkalyon@stevens.edu- Co-Chair; Jerry Salan, Senior chemical Scale-up Technologist, NAVSEA Indian Head Division, 101 Strauss Avenue, Code T236, Indian Head, MD 20640-5035, Phone Number: (301) 744-6123, Fax Number: (301) 744-6425, Email:
jerry.salan@navy.milThe session will cover the rheology and processing of energetic materials, using conventional and novel processing technologies. The scope includes the mathematical modeling and simulation of the processing operation, experimental studies, process control, structure versus the processing history relationships, and various factors which govern the safety of the process, including the conditions which give rise to demixing, segregation, and formation of hot spots.
Improvements In The Synthesis Of Guanidinium Azotetrazolate (Guzt)
Shannon Lenahan, Chemical Development, Naval Surface Warfare Center Indian Head Division, 101 Strauss Ave., Indian Head, MD 20640, Jerry Salan, Naval Surface Warfare Center Indian Head Division, 101 Strauss Ave., Indian Head, MD 20640 and Claire Wells, NSWC Dahlgren, Dahlgren, VA 22448
Guanidinium azotetrazolate (GuZT) is a high-nitrogen material with potential application as a burning rate modifier in gun propellants and ingredient for explosives. Beyond its explosive properties and burning rate modification effects in formulation, it appeals to the energetics industry because of its straightforward synthesis and relative insensitivity to friction and impact. To date, it has been manufactured at Indian Head at scales of up to 50 gallons, and preparations for synthesis at twice that scale are underway.
In preparation for this endeavor, experiments were performed to determine the optimum operating parameters for maximizing yield and purity for the 100-gallon scale process. First, the reaction concentration was increased by over twofold to maximize the quantity of reacting materials in the reactor at one time. This strategy reduced the labor cost/kg by more than 50%. Early laboratory synthesis required the addition of solid guanidine hydrochloride (GuHCl) to a solution of sodium hydroxide and sodium azotetrazolate (NaZT).
This process worked well to yield pure GuZT product. However, as the scaling process progressed, the sensitivity of GUZT to impact increased significantly. Changing the GuHCl from a solid feed to a solution resulted in the impact sensitivity returning to its less sensitive values. It was suspected that the GuHCl was included in the GUZT crystal lattice during the addition and subsequent reaction. Feeding the reactant as a solution allowed the reaction to take place in solution, yielding purer insoluble GUZT product.
Next, a series of experiments was performed to optimize the yield and purity of the GuZT product. Factors of interest included temperature at filtration, ratio of reactants, and reaction temperature. Real-time crystallization data was also collected with an eye toward solving potential crystal morphology challenges. This series of experiments was completed, in addition to experiments used to determine the washing parameters of the final product. These efforts yielded factors significantly influencing the measured responses, which are implemented at the 100-gallon scale. Efficacy of the study is reported.
Download full paper in PDF format.Ignition Of Metal Powders By Electric Spark
Ervin Beloni1, Mikhaylo A. Trunov1 and Edward L. Dreizin2, (1)Mechanical Engineering, New Jersey Institute of Technology, 138 Warren St., Newark, NJ 07102, (2)Chemical Engineering, New Jersey Institute of Technology, 138 Warren St., Newark, NJ 07102
Energetic formulations with metal fuel additives are extensively used in propellants, explosives, pyrotechnics, and incendiaries. Currently, replacement of regular metal powders with nanocomposite metal-based materials is being considered. Such nanocomposite reactive materials are capable of very high reaction rates while maintaining the high combustion enthalpies characteristic of metals. However, such novel reactive nano-materials are often highly sensitive to impact, friction, and electrostatic discharge, making them difficult to handle.
In particular, their high electrostatic discharge sensitivity (ESD) was reported. While ESD testing is common and standardized, the mechanisms of powder ignition by electric spark remain unclear. This project is aimed to establish the relationship between thermal ignition mechanism for metal powders and related nanocomposites and their ESD sensitivity. The project includes both experimental and modeling components. An explicit numerical model of the heat transfer within a powder bed subject to a pulsed electric discharge will be developed.
The model will initially describe the behavior of metal powders for which the thermal ignition kinetics is well established and quantified, such as spherical magnesium. It will be further expanded for novel nanocomposite materials for which the kinetics of exothermic processes leading to ignition will be determined in separate experiments. The predictions will be validated experimentally using a standard ESD testing apparatus. This paper will present initial model formulation and experimental results.
High Energy Chemistry And Its Chemical Engineering Challenges
Jerry Salan1, Patrick B. Skahan1 and Kimberly Hanson2, (1)Naval Surface Warfare Center Indian Head Division, 101 Strauss Ave., Indian Head, MD 20640, (2)Naval Surface Warfare Center Indian Head Division, 101 Strauss Avenue, Indian Head, MD 20640
he majority of synthetic routes to energetic materials involves at least one step involving high energy chemistry. Although steps are typically taken early in the development phase to evaluate alternatives to high energy chemistry there will always be a need to address the process safety for these types of reactions when developing energetic materials. An appreciation of the risks and potentially catastrophic consequences involved with high energy chemistry and the products of such reactions must be maintained.
Indian Head Division, Naval Surface Warfare Center recently scaled up the nitration of 2,6 dimethoxydinitropyrazine. This energetic intermediate's chemical reaction was evaluated using reaction calorimetry and contiuous IR measurements to determine heat flow, reaction progression and identify factors of interest for the process. One key parameter observed was the reagent order of addition and its affect on heat flow. The process was also evaluated for processing continously in lieu of the traditional batch process. Various chemical engineering challenges including heat flow, product stability and isolation are evaluated. The results of these experiments and rationale for scaling high energy chemistry will be presented.
Laser Ignition Of Aluminum Particles In Water
Salil Mohan, Department of Mechanical Engineering, New Jersey Institute of Technology, 138 Warren St., Newark, NJ 07102 and Edward L. Dreizin, Chemical Engineering, New Jersey Institute of Technology, 138 Warren St., Newark, NJ 07102
This study presents experimental results of ignition of Al particles with a CO2 laser in water vapor environment. Al powder, with nominal particle sizes in the range of 4.5 µm – 7 µm, is aerosolized using a parallel plate capacitor by charging particles contacting the electrodes. A thin, laminar aerosol jet is carried out by nitrogen heated to ~150 °C through a small opening in the top electrode and is fed into a focused CO2 laser beam.
A shroud flow of superheated steam, also at ~150 °C, is maintained around the central aerosol jet. The velocities of particles in the jet can be varied in the range of 0.1 – 3 m/s. The particle velocity is controlled by the inert gas jet velocity while keeping the shroud steam flow velocity constant. Numerical simulation using Fluent CFD code was used to determine the gas composition at the laser focal spot. For each selected central flow velocity, the laser power was increased until the particles were observed to ignite. The ignition was detected optically using a photomultiplier.
The ignition thresholds for spherical aluminum powder were measured at varied particle velocities resulting in varied heating rates and vapor concentration. Similar experiments were conducted by replacing superheated steam with hot air. Laser ignition threshold from air was found to be lower than that for superheated steam.
Twin Screw Extrusion Of Nanoenergetics With Processing Geometries That Are Tunable To The Targeted Thermo-Mechanical History
Dilhan Kalyon1, Seher Ozkan1, Moinuddin Malik2, James E. Kowalczyk3 and Mark Mezger4, (1)Stevens Institute of Technology, Castle Point St., Hoboken, NJ 07030, (2)HfMI, Stevens Institute of Technology, Castle Point St., Hoboken, NJ 07030, (3)Material Processing & Research, Inc., 31 Mercer St. 2-E, Hackensack, NJ 07601, (4)US Army Research Development Engineering Command, US Army, Picatinny Arsenal, Dover, NJ 07806-5000
The dispersion of nanoparticles into energetic formulations requires relatively high shearing stresses to be applied to allow the deagglomeration of particle clusters and the encapsulation of the separated nanoparticles by the binder phase. For such dispersion the twin screw extrusion process provides multiple advantages over the conventional batch processing methods including a significantly higher surface to volume ratio for better process and product quality control and flexible and tunable geometries (combinations of reversing or forwarding fully-flighted or kneading disc type screw elements configured at differing pitches and stagger angles) to tailor the thermo-mechanical history that the energetic formulation is to be exposed to during the incorporation of the nanoparticles.
Here the technology base will be introduced and results from processing studies obtained with a MPR mini twin screw extruder, in conjunction with 3-D FEM based mathematical models of the process and the detailed rheological characterization of formulations involving gel based binder systems and different types of nanoalumina, will be presented.
Experimental Investigation Of Aluminum Oxidation In Water
Mirko Schoenitz, Mikhaylo A Trunov and Edward L Dreizin, Chemical Engineering, New Jersey Institute of Technology, University Heights, Newark, NJ 07102
The use of aluminum as an energetic component in pyrotechnics, solid fuel formulations, and propellants is motivated by its high gravimetric oxidation enthalpy. However, the rate of its oxidation is significantly lower than that of other, typically hydrocarbon-based, components of fuel formulations. As a result, aluminum combustion will take place in the combustion products of those components, i.e. H2O and CO/CO2. In order to design and optimize fuel formulations as well as the devices where these formulations are used, the thermodynamics and kinetics of the reaction of aluminum with the component gases need to be understood.
This report shows results of oxidation of micron-sized aluminum powders in water-argon gas mixtures at temperatures between 300–1100 °C using thermogravimetry. In this environment, aluminum oxidizes in several distinct stages. Initial slow oxidation between 300–500 °C is followed by stepwise oxidation of approximately 5-10 % near 550 °C. At low heating rates (<5 K/min), the next sharp oxidation step of about 10 % is observed at the aluminum melting point of 660 °C.
This oxidation step shifts to higher temperatures at increased heating rates. The initial two oxidation steps are followed by one or more distinguishable spread-out oxidation reactions that terminate when the material is fully oxidized above 1000 °C. The temperatures and degrees of oxidation achieved in the individual steps depend on the particle size, the heating rate, and the water concentration in the atmosphere. The results are comparable to previously published results of oxidation in oxygen-argon mixtures, although there are significant differences. Most notably, the oxidation step associated with aluminum melting was not previously observed. Phase analysis will be conducted on fully and partially oxidized powders, and a mechanistic model for aluminum oxidation in water will be developed.
Bis Triaminoguanidinium Azotetrazolate (Tagzt) Scale Up And Production
Christopher M. Radack, Indian Head Div., Naval Surface Warfare Center, Indian Head Division, Indian Head, MD 20640-5035, Shannon Lenahan, Chemical Development, Naval Surface Warfare Center Indian Head Division, 101 Strauss Ave., Indian Head, MD 20640 and Jerry Salan, Naval Surface Warfare Center Indian Head Division, 101 Strauss Ave., Indian Head, MD 20640
The manufacture of the Class 1 explosive bis triaminoguanidinium azotetrazolate (TAGZT), along with its precursor sodium azotetrazolate (NaZT), has been successfully demonstrated by personnel at the Naval Surface Warfare Center, Indian Head Division (NSWC-IHD). In 2003 NSWC-IHD successfully validated a 100 gallon batch scale process working with synthesis chemists at Los Alamos National Laboratory (LANL). Recently, the manufacturing processes for TAGZT and its precursor were engineered to minimize the operators' exposure and optimized to maximize the product yield.
The yield of NaZT at the 100-gallon scale was approximately 10 kilograms. The existing TAGZT process at the 100-gallon scale required approximately 30 kilograms of NaZT to make one 30-kilogram batch of TAGZT. This stated process required the isolation, drying, and storage of the dry NaZT in preparation for the TAGZT synthesis. Handling the NaZT is neither advisable nor desired, so an alternative process was engineered. The new TAGZT process has eliminated the isolation and handling of the NaZT. In the new process the NaZT is collected and temporarily stored in a 100 gallon Nutsche filter until required for the TAGZT synthesis.
A yield improvement in the synthesis of the NaZT·5H2O was accomplished by increasing the reactant concentration twofold over the originally demonstrated procedure. This doubled the amount of NaZT·5H2O produced per batch. The optimization of the TAGZT synthesis was achieved by changing two process variables. The reactant concentration was increased, similar to the optimization of NaZT·5H2O, and the crystallization temperature was lowered. The amount of TAGZT recovered per batch increased by 70%.
The engineering challenges will be presented along with an economic assessment of this energetic ingredient.
Download the full paper in PDF format.628 Environment & Lifecycle 03E02
3:30 PM to 6:00 PM
M - Salon F (Marriott Salt Lake City-Downtown)
- Chair: Charles R. Painter, Director, Navy Energetics ManTech Center, NAVSEA Indian Head Division, 101 Strauss Avenue, Code CA8, Indian Head, MD 20640-5035, Phone Number: (301) 744-6772, Fax Number: (301) 744-6425, Email:
charles.r.painter@navy.mil- Co-Chair: Michael Cushman, Manager Advanced Materials & Biotechnology, InfoSciTex, 303 Bear Hill Road, Waltham, MA 02451-1016, Phone Number: (781) 890-1338 ext. 225, Fax Number: 781-890-1330, Email:
mcushman@infoscitex.comThis session will focus on the lifecycle environmental issues associated with energetic materials. Topical areas include: pollution prevention, compliance, and restoration issues/technologies related to the synthesis, production, formulation, testing, training, demilitarization, and cleanup of energetic materials.
3:30 PM
628a Physicochemical Measurements on Insensitive Munitions Compound, N-Methyl-4-Nitroaniline (Mna) for Environmental Applications.
Veera Boddu1, Krishnaiah Abburi1, Stephen W. Maloney1, and Reddy Damavarapu2. (1) Environmental Processes Branch, US Army Engineer Research and Development Center, 2902 Newmark Drive, PO Box 9005, Champaign, IL 61822, (2) Energetics and Warheads Division, U.S. Army - Armament Research, Development and Engineering Center, Picatinny Arsenal, NJ
Physicochemical properties such as solubility, octanol-water partition coefficient and Henry's law constant of energetic compounds provide invaluable information for the overall understanding of environmental distribution, biotransformation, and potential treatment processes. The solubility, octanol-water partition coefficient, and Henry's law constant were measured for N-methyl-4-nitroaniline (MNA), an insensitive munitions' compound at 25, 35, and 45oC. The effect of ionic concentration on solubility, using electrolytes such as NaCl and CaCl2, was also studied.
The aqueous solubility of MNA was measured by adding an excess amount of the solid compound (0.2 g) to a flask containing deionized water (100 mL). The equilibrium concentration of MNA was determined using UV spectroscopy. The octanol-water partition coefficients (log KOW) values were determined directly with the shake-flask procedure. A modified gas-purging technique was used for the determination of Henry's law constant (HLC) of MNA. The data on the physico-chemical parameters were correlated using the standard van't Hoff equation. The enthalpy and entropy of phase transfer were derived from the experimental data. Details of the experimental studies and results will be presented.
3:55 PM
628b Thermophysical Property Prediction Of Energetic Materials With Atomistic Computer Simulations
Nandhini Sokkalingam1, MaryBeth Helen Ketko2, Aishuang Xiang2, and Jeffrey J. Potoff2. (1) Department of Chemical Engineering, Wayne State University, 5050 Anthony Wayne Dr, Detroit, MI 48202, (2) Department of Chemical Engineering, Wayne State University, 5050 Anthony Wayne Dr., Detroit, MI 48202
The majority of DOD generated hazardous waste streams can be traced to the production, maintenance and disposal of weapons systems. In this work, we discuss the use of molecular simulation as a predictive tool for the determination of bioaccumulation potential of a particular energetic material.
Newly developed molecular models, or "force fields" for dinitroanisole (DNAN) and n-methyl-p-nitroaniline (MNA) are presented. Monte Carlo simulations are used to predict the vapor-liquid coexistence curves, vapor pressures and critical points for each compound. Molecular dynamic simulations coupled with thermodynamic integration are used to determine octanol-water partition coefficients, key predictors in the bioaccumulation potential for each material.
4:20 PM
628c Green Methodologies for Separation of Explosive Components Rdx and Hmx
Veera Boddu1, Reddy Damavarapu2, Ann J. Randolph3, and Jessie Creamean1. (1) Environmental Processes Branch, US Army Engineer Research and Development Center, 2902 Newmark Drive, PO Box 9005, Champaign, IL 61822, (2) Energetics and Warheads Division, U.S. Army - Armament Research, Development and Engineering Center, Picatinny Arsenal, NJ, (3) Environmental Processes Pranch, US Army Engineer Research and Development Center, 2902 Newmark Drive, PO Box 9005, Champaign, IL 61822
Explosive compounds with Reduced Sensitivity (RS) or Insensitive Munitions (IM) are desired for reasons of safe loading, pack and assemble operations and to meet the improved performance requirements of the energetics. The two most widely used dense energetic materials are the monocyclic nitramines RDX (1,3,5-trinitro-1,3,5-hexahydrotriazine,) and HMX (1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane).
The manufacturing process for these explosives yield a mixture of both RDX and HMX. The sensitivity of the final explosive depends on the composition of RDX and HMX and increases with the composition of HMX. There is a need to selectively separate HMX from the mixture in order to develop RS and IM munitions. This presentation summarizes our research on environmentally benign processes to separate HMX from RDX. The approach was to dissolve the crude RDX and HMX mixture into a suitable solvent and then separate the components. Our approach focused on identifying a suitable solvent to solubilize RDX and HMX and evaluating membrane and chromatographic separation processes.
4:45 PM
628d Assessment Of Waste Treatment Technologies For Energetic Materials
Rebecca K. Toghiani1, Hossein Toghiani1, Stephen W. Maloney2, and Veera Boddu2. (1) Chemical Engineering, Dave C. Swalm School of Chemical Engineering, Mississippi State University, 330 Swalm, Mississippi State, MS 39762, (2) Environmental Processes Branch, US Army Engineer Research and Development Center, 2902 Newmark Drive, PO Box 9005, Champaign, IL 61822
One important criterion in the development of an energetic material is an assessment of its potential environmental impact. During production, waste streams generated may contain small amounts of the energetic material. Knowing how this material may partition in the environment is beneficial to development of waste treatment technologies. Physicochemical parameters define how this partitioning will occur.
While these parameters can be experimentally determined once suitable amounts of the energetic material are available for testing, the ability to predict these important properties using the structure of the energetic material will provide a means for assessing their environmental impact during the preliminary development stage. In this work, the chemical structures of six energetic materials are used to estimate their physicochemical parameters.
These energetic materials have been identified by researchers at CERL as materials under consideration as energetics in short-term development or longer-term development, and include dinitroanisole (DNAN), n-methyl-p-nitroaniline (MNA), nitro-triazolene (NTO), triaminotrinitrobenzene (TATB), dinitro pyrazole (DNP) and m-trinitro imidazole (MTNI). Aqueous solubility as a function of temperature, octanol-water partition coefficient and Henry's constant are predicted and used to assess the potential viability of commonly employed wastewater treatment technologies. Development of a QSPR/QSAR relating the structure of the energetic material to potentially effective treatment technologies is discussed.
5:10 PM
628e Navy Demilitarization R&d Efforts
Joshua R. Geary, NSWC Crane, 300 Highway 361, Attn: Code 4073, Building 2540, Crane, IN 47522
The primary objective of the Demilitarization Technology Project at Naval Surface Warfare Center, Crane Division (NSWC Crane) are to pursue the development of safe and environmentally acceptable demil processes that will remove, reclaim, and reuse the energetic material found in munition items; for those items where it is unfeasible to reclaim the energetic, contained detonation technology is being pursued. The Demil Technology Project increases the joint service activities of Team Crane by strengthening the bond between NSWC Crane and Crane Army Ammunition Activity (CAAA) by providing new demil capabilities to CAAA for the benefit of its demil execution mission. Some of the technologies being explored and developed by NSWC Crane include: Abrasive Waterjet Cutting/Washout, Cryofracture of Submunitions, Induction Heating Melt-Out, Manufacturing Commercial Products from Large-Grain Gun Propellants, HMX Recovery and Requalification, Magnesium Recovery, Contained Detonation Chambers, and Molten Salt Oxidation.
Updated 12/5/2007
