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Award Detail

Doing Business As Name:SUNY at Buffalo
  • Mark T Swihart
  • (716) 645-1181
  • Vasilis Papavassiliou
Award Date:01/26/2011
Estimated Total Award Amount: $ 278,811
Funds Obligated to Date: $ 280,810
  • FY 2011=$278,811
  • FY 2012=$1,999
Start Date:03/01/2011
End Date:02/28/2014
Transaction Type:Grant
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.041
Primary Program Source:040100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:GOALI: Flame-based Synthesis of Metal Nanoparticles at Millisecond Residence Times
Federal Award ID Number:1066945
DUNS ID:038633251
Parent DUNS ID:020657151
Program:Proc Sys, Reac Eng & Mol Therm

Awardee Location

Street:520 Lee Entrance
Awardee Cong. District:26

Primary Place of Performance

Organization Name:SUNY at Buffalo
Street:520 Lee Entrance
Cong. District:26

Abstract at Time of Award

PI: Swihart, Mark Institution: SUNY at Buffalo Proposal Number: 1066945 Title: GOALI: Flame-based Synthesis of Metal Nanoparticles at Millisecond Residence Times The PIs plan to apply the combined expertise of their University at Buffalo (SUNY) and Praxair teams to develop a new flame-based process for producing metal nanoparticles. Printed electronics, antimicrobial plastics and other applications of metal nanoparticles are rapidly growing. Currently, these particles are prepared using large quantities of solvents, high-value surfactants and polymers. A gas-phase flame-based process will provide a lower-cost, more environmentally friendly route to these nanomaterials if it can provide sufficient control of size, size distribution, and degree of agglomeration. Most large-scale production of metal oxide nanomaterials (TiO2, ZrO2, etc.) and carbon black is done in flame processes for these reasons. However, this is not the case for most metals, because they oxidize in the flame. The approach pursued here, based on a thermal nozzle technology developed at Praxair, provides the high temperature, short residence time, rapid mixing, and reducing conditions needed for metal nanoparticle production. The nozzle and downstream reactor provide a highly uniform environment for particle growth, improving control of particle size, size distribution, and morphology compared to other gas-phase processes. Most importantly, this approach decouples the precursor chemistry from the flame chemistry, allowing use of precursors such as low-cost aqueous salts that cannot be used in other flame-based methods, and allowing the residence time for particle formation to be controlled independently of the flame dynamics. Specific aims of the proposed research are to: 1. Systematically study the effects of key operating parameters on single-component nanoparticle size distribution and morphology, to optimize yield and control particle size distribution. 2. Explore production and structure control of multicomponent (alloy and core-shell) nanoparticles, coated metallic nanoparticles, and additional novel nanomaterials including dendritic carbon. 3. Develop, validate and apply computational reactor models to understand the physico-chemical basis of the experimental results and enable predictive, rational process improvement. 4. Complete a cost analysis and market analysis to identify pathways to commercialization. Intellectual Merit: The intellectual merit of this work derives from the novel adaptation of an existing technology for a promising and very different new purpose. The thermal nozzle reactor is elegant in its simplicity; it merely separates combustion from particle formation by passing the hot combustion products through a converging-diverging nozzle. The resulting hot gas jet provides effective atomization of liquid precursors and extraordinarily fast mixing. Rapid initiation and termination of particle formation (by heating and quenching) are the keys to the production of nanoparticles in the gas phase at high throughput, and this is exactly what this system provides. Moreover, the PIs will investigate the formation of alloy and core-shell particles and novel carbon nanomaterials in this system, potentially generating structures that cannot be obtained by other methods. State-of-the-art aerosol dynamics modeling will be performed in parallel with experiments, providing fundamental insight into the particle formation process. The combined expertise of the UB and Praxair teams is essential to the success of the project. Broader Impacts: The work will lead to development of a new high-throughput low-cost process for the production of metallic nanoparticles. This will have technological impact by lowering costs and expanding the range of application of these materials. Through this work, a Ph.D. student, MS students, and undergraduates will be trained in aerosol synthesis of nanomaterials and develop cross-disciplinary chemistry, materials science, and chemical engineering skills. All participants will benefit from the academic-industrial collaboration. Undergraduates will participate through the NSF REU program, and additional targeted programs such as the McNair Scholars and Louis Stokes Alliance for Minority Participation (LS-AMP) programs. This project will allow the PIs to build on their growing success in recruiting minority participants, and expand it with outreach to high-school students and teachers. Transformative Nature of this Project: This project has potential to transform the way nanoparticles of metals and other non-oxide materials are produced. This is a novel millisecond residence-time reactor for nanomaterials. The impact of this process on nanomaterials processing and aerosol reaction engineering could very well match the impact of other millisecond contact-time reactors (e.g. those developed by Lanny Schmidt et al.) on reaction engineering for reforming and partial oxidation, affecting directions of both scientific research and industrial practice.

Publications Produced as a Result of this Research

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Sharma, M.K., Buchner R.D., Scharmach W.J., Papavassiliou V., Swihart M.T. "Creating conductive copper-silver bimetallic nanostructured coatings using a high temperature reducing jet aerosol reactor" Aerosol Science and Technology, v.47, 2013, p.858. doi:10.1080/02786826.2013.796338 

William J. Scharmach, Sharma, M.K., Raymond D. Buchner, Vasilis Papavassiliou, Gaurav N. Vajani, and Mark T. Swihart "Amorphous carbon encapsulation for improved collection efficiency in aerosol processes" AIChE Journal, v.59, 2013, p.4116.

Project Outcomes Report


This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

The goal of this project was to develop a new cost-effective technology for producing multicomponent metal nanoparticles for use in applications such as printable electronics. Very small particles of metal (below 50 nm in diameter, or 1/1000th of the diameter of a typical human hair) require lower processing temperatures than larger particles. These small particles can sinter (melt into one another enough to form electrical contacts) at temperatures where low-cost materials such as paper and plastic are stable. They are also compatible with printing technologies such as ink-jet printing that cannot use larger particles. At present, silver is the metal that is most commonly used in printable electronics. However, silver is relatively expensive, and lower cost solutions are needed if printable electronics are to achieve more widespread applications. Ultimately, low-cost printed electronics could allow exciting new developments, such as the integration of displays and sensors into printed materials (somewhat like the Daily Prophet newspaper in the Harry Potter movies). In addition, optical barcodes on consumer goods could be replaced by printed radio-frequency identification (RFID) tags that can be read remotely. This would, for example, eliminate the need to remove each item from a grocery cart to scan it.  The whole cart could simply be passed over an RFID scanner that would read the tags on all the products simultaneously. The availability of low-cost metal nanoparticles for formulating inks that can produce structures with high electrical conductivity using low-temperature processing is key to the advancement of these technologies.

This project, a collaboration between researchers at the University at Buffalo (SUNY) and Praxair, Inc. developed a new process for producing metal nanoparticles from low-cost environmentally-friendly solutions of metal salts in water, with low-cost energy from a clean-burning hydrogen flame. In this process, dubbed the High Temperature Reducing Jet method, hydrogen is burned with a limited amount of oxygen to create a hot gas stream that contains excess hydrogen. This hot gas goes into a converging-diverging nozzle that accelerates it to a very high speed. Water-based solutions of metal salts, such as copper nitrate, are pumped into this nozzle from the sides (see Figure 1). The hot, high-velocity gas stream sprays these into tiny droplets that very quickly evaporate. The precursor compound decomposes to produce gas-phase molecules that react to produce metal nanoparticles. The excess hydrogen in the gas mixture reacts with oxygen from the precursors to ensure that metal nanoparticles, and not metal oxide nanoparticles  are formed (e.g. copper metal, not the blue-green copper oxide one might see on an aging bronze statue). As the nanoparticles leave the reactor, they are mixed with a stream of cold, inert nitrogen gas, which cools them down so that they do not grow further or stick together and melt into larger particles.

An important feature of this technology is that the metal atoms in the precursor solution are fully converted into the product nanoparticles. Thus, no metal is wasted, and the composition of the product particles is determined by the composition of the precursor solution. In this study, we demonstrated the production of two-component copper-silver nanoparticles, three-component copper-silver-tin nanoparticles, and two-component copper-nickel alloy nanoparticles. All of these showed high electrical conductivity in thin films sintered at relatively low temperatures (200 to 300 degrees celsius). In copper-silver-tin  mixtures we were able to achieve electrical conductivity similar to that of a pure silver nanoparticle film while using only 20 percent silver. This could produce a major cost reduction in inks for printed electronics. We demonstrated that, although both pure copper and pure nick...

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