Synthesis of worm and chain-like nanoparticles by a microfluidic reactor process
We demonstrate a room temperature microfluidic reactor (MFR) process for the synthesis of worm-like and chain-like shaped metallic nanoparticles (NPs). These high aspect ratio NPs are in geometrically metastable states, which can be further transformed into ellipsoidal, spherical, or short rod-like species with enhanced crystallinity after their solutions are stirred for several hours and/or undergo sonication for more than half an hour, evidenced by their transmission electron microscope (TEM) images, selected area electron diffraction (SAED), and X-ray Diffraction (XRD). Analysis on the relative stronger shape control ability by the microfluidic process than by the batch process suggests that the attachment and merging of pre-formed nanoclusters along the flow orientation in the microchannel slits may be the main reason for the formation of non-spherical shaped NPs. The result indicates that the room temperature microfluidic process has the potential to assemble primary nanoclusters into two-dimension architectures (i.e., chain-like networks).
KeywordsNanoparticle Metallic Synthesis Shape Crystallinity Assembling microfluidic reactor Room temperature Nanomanufacturing
The authors appreciate the financial support from Natural Science Foundation of China (NSFC: 50971010), SRF and SEM from Chinese Education Ministry, New Teacher Funds (2008-00061025) of Chinese Education Ministry, and the Research development funds for new teachers at Beihang University (211109). The authors appreciate the time and effort by Dr. L. L. Henry, Department of Physics, Southern University and A&M College, Baton Rouge, Louisiana, USA, in reviewing the manuscript for publication.
- Cullity BD, Stock SR (2001) Elements of X-ray diffraction, Chap 5, Appendix 5. Prentice Hall, Upper Saddle RiverGoogle Scholar
- Song Y (2009) Microfluidic reactor process for controlled synthesis of nanoparticles. China Patent Appl No. CN200910085974.3, pp 17Google Scholar
- Song Y (2010) Fabrication of multi-level 3-dimension microstructures by phase inversion process. Nano-Micro Lett 2:95–100Google Scholar
- Song Y, Elsayed-Ali, HE (2010) Aqueous phase Ag nanoparticles with controlled shapes fabricated by a modified nanosphere lithography and their optical properties. Appl Surf Sci 256:5961–5967Google Scholar
- Song Y, Modrow H, Henry LL, Saw CK, Doomes EE, Palshin V, Hormes J, Kumar CSSR (2006) Microfluidic synthesis of cobalt nanoparticles. Chem Mater 18:2817–2827Google Scholar
- Song Y, Jin P, Zhang T (2010) Microfluidic synthesis of Fe nanoparticles. Mater Lett 64:1789–1792Google Scholar
- White FM (2003) Fluid mechnics, 5th edn. McGraw-Hill Professional Publisher, New YorkGoogle Scholar