Microreaction Technology for Cheaper, Greener and Safer Nanomaterial Development

Why is this technology needed?

Many nanomaterials are expensive and toxic, causing significant environmental health and safety issues. [Sigma-Aldrich catalog online (http://www.sigmaaldrich.com), accessed May 21, 2008. CdSe and ZnS quantum dots priced at $499 per 50mg and $164 per 10 mg]. This is in large part because chemical companies manufacture nanomaterials either in expensive gas-phase reactors or in batch using large stirred tanks with poor throughputs and yields. Batch processing makes it difficult to measure and control the purity of nanomaterials during manufacture.

How does this technology address the need?

The use of high-throughput (tens to hundreds of liters per minute) microreactors provide solution-phase heating and mixing rates several orders of magnitude faster than conventional batch (stirred tank) reactors leading to cheaper and greener synthesis. OSU and the University of Oregon (UO) have demonstrated continuous microchannel diafiltration techniques that have resolved nanoparticle diameters as close as 1.5 nm, thereby opening a route to low-cost, high-purity extraction (Figure 1). OSU has demonstrated high-rate nanotoxicity screening methods, which, in combination with microreactors, can lead to the rapid development of safer nanomaterials.

How is MBI contributing to the solution?

In the microreactor synthesis of undecagold (Au11) nanoparticles, OSU, in collaboration with UO, recently increased throughput by a factor of 40 while doubling material yield and halving solvent usage compared with batch reactors (Figure 2). OSU researchers have increased throughput by a factor of 1000 by synthesizing solution-phase nanomaterials with microreactors rather than batch reactors.

The Oregon Process Innovation Center (OPIC) is a unique facility within the MBI for developing benchtop nanomaterial chemistries and demonstrating pilot-scale chemical process development and in-process characterization. Nanomaterial characterization is greatly facilitated by the Linus Pauling Science Center at OSU and NIST-quiet ONAMI facilities at the University of Oregon.

Collaborators:

• Chih-hung Chang, Director of OPIC
• Brian K. Paul

For additional information . . .

To learn more about this technology, please contact Chih-hung Chang.

Related literature:

G. Yang, “CMP wastewater management using the concepts of design for environment,” Environmental Progress, 21(1): 57-62, 2002.

C. Chang, B.K. Paul, V.T. Remcho, S. Atre, J.E. Hutchison, “Synthesis and post-processing of nanomaterials using microreaction technology,” J Nanoparticle Res., 10(6): 2008.

S.F. Sweeney, G.H. Woehrle, J.E. Hutchison, “Rapid Purification and Size Separation of Gold Nanoparticles via Diafiltration,” J. Am. Chem. Soc, 128, 3190-3197, 2006.

J.T. Rundel, B.K. Paul, V.T. Remcho, “Organic Solvent Nanofiltration for Microfluidic Purification of PAMAM Dendrimers,” J Chrom A, 1162(2), 2007, 167-174.

C. Usenkoa, S. Harper and R. Tanguay, “In vivo evaluation of carbon fullerene toxicity using embryonic zebrafish,” Carbon, 45(9): 1891-1898, 2007.

S. Harper, C. Usenko, J.E. Hutchison, B.L.S. Maddux, R.L. Tanguay, “In vivo biodistribution and toxicity depends on nanomaterial composition, size, surface functionalisation and route of exposure,” Journal of Experimental Nanoscience, 3(3): 195–206, 2008.

S. Liu, C. Chang, B.K. Paul and V.T. Remcho, “Convergent synthesis of polyamide dendrimer using a continuous flow microreactor,” Chem. Engr. Journal, 135(1), 2008, S333-S337.

C. Tseng, B. Paul, C. Chang and M. Engelhard, “Continuous Precipitation of Ceria Nanoparticles from a Continuous Flow Micromixer,” Electrochem. Solid-State Letters, in first review; Tseng, C.T. and B.K. Paul, “Comparison of Batch Mixing and Micromixing Approaches in the Synthesis and Deposition of Ceria Nanoparticles,” Transactions of NAMRI, 35, Ann Arbor, MI, May 23-25, 2007.