Grantee Research Project Results
Final Report: A Solvent-Free, Nanopowder Production Method
EPA Contract Number: EPD11055Title: A Solvent-Free, Nanopowder Production Method
Investigators: Rolfe, Sara L
Small Business: Eltron Research & Development Inc.
EPA Contact: Richards, April
Phase: I
Project Period: March 1, 2011 through August 31, 2011
Project Amount: $80,000
RFA: Small Business Innovation Research (SBIR) - Phase I (2011) RFA Text | Recipients Lists
Research Category: Small Business Innovation Research (SBIR) , SBIR - Innovation in Manufacturing
Description:
The purpose of this SBIR Phase I was to develop a new environmental, solvent-free, nanopowder production method that was competitive with existing nanopowder production prices. High purity ZnO nanopowder was produced and a preliminary economic analysis was performed. Several technical goals as described in the Foresight Science & Technology Niche Analysis™ were achieved:
Technical Goal | Phase I Achievement | |
---|---|---|
Price | $57/kg | $8.50/kg |
Mean Particle Diameter | 100 nm | 99 nm |
Purity | 99% | >99.9% |
The Phase I research consisted of design and construction of the nanopowder reactor, production of nanopowder ZnO, characterization of the nanopowder produced, and a technoeconomic analysis to show the commercialization potential of the technology. The laboratory reactor system was modeled using CFD analysis to ensure high vaporization rates of the precursor and adequate gas mixing and velocity. A custom furnace system and a secondary containment vessel to hold the reactor were constructed. A specialty auger system and filtration system were designed for continuous operation of the system. Several batches of ZnO nanopowder were produced and tested for size, shape, surface area and purity. Eltron’s process engineers prepared an initial estimate of the economic viability of a commercial-scale zinc oxide nanoparticle production facility.
Summary/Accomplishments (Outputs/Outcomes):
High purity ZnO nanopowder was produced and characterized. The following is a summary of results for the best sample. X-ray diffraction shows a hexagonal wurtzite ZnO pattern. Surface area analysis resulted in a surface area of 10 m2/g, which corresponds to a median particle size of 99 nm. X-ray fluorescence purity analysis shows that the nanopowder, when compared to the precursor, shows drastically reduced levels of copper and iron and nearly undetectable levels of lead and bismuth. Among the samples, scanning electron microscopy shows a wide range of particle shapes including spherical, rod and tetrapod. Transmission electron microscopy shows nanopowder particles with approximate diameters of 100 nm. The profitability analysis of the proposed production facility shows a required market price for such a product would need to be $8.5/kg for a 16 percent return on investment and a payback period of 2.5 years.
Conclusions:
The Phase I reactor had problems with clogging and low yields. High purity nanoparticle ZnO with a surface area of 10 m2/g, however, was produced. This is a rather low surface area for a nanopowder, and Eltron Research & Development Inc. (Eltron) expects to increase this to 30-60 m2/g in the Phase II project. An improved design at a much larger scale will be demonstrated. Larger scale production will be much closer to that anticipated for commercial scale and should give a better representation of the technology. In addition, many of the problems encountered in the Phase I reactor shall be avoided with the Phase II reactor.
Commercialization:
Eltron has begun to contact sunscreen/cosmetic producers, rubber and tire manufacturers, and catalyst manufacturers as a first stage towards commercialization of this technology. Nanoparticle production is an important and growing industry. In 2006, zinc oxide, gold, titanium dioxide, and calcium phosphate nanoparticles accounted for 90% of the nanoparticle market. Consumer product nanoparticle applications include sunscreens, dental applications, and cosmetics. Slurries of nanoparticles are used for chemical mechanical polishing/planarization (CMP), which is used in computers and electronics production. TiO2 and ZnO nanopowders and dispersions increasingly are being used in sunblocks including products such as Clinique and Johnson & Johnson’s sensitive skin and baby products, Cellex-C and Obagi’s skin-care line, and Oil of Olay and Revlon’s daily-wear skin lotions and foundation with UV protection. ZnO also has many catalyst applications including water-gas-shift and sulfur sorption. Other nanoparticle ZnO applications include deodorant, antimicrobial textiles; rubber products; anti-aging effects in paint, coatings, and plastic; piezoelectrics; and capacitors.
Supplemental Keywords:
nanopowder production, solvent-free nanoparticle production;The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.