1. 1. SOLID, LIQUID AND GAS PHASE SYNTHESIS OF NANOMATERIALS A Harish Kumar I M.Tech Biotechnology 2014402008 NANOBIOTECHNOLOGY
2. 2. Nanotechnology is the manipulation of matter at least one dimension sized from 1 to 100 nanometres -NNI DIFFERENT APPROACHES FOR NANOFABRICATION Top down approach Bottom up approach [Bulk material broken [Building or assembling from down into small pieces] small pieces as atoms or molecules] + Scale up is easy + Control of particle size, morphology, + No need of sophisticated instruments + High purity
3. 3. Synthesis of nanoparticles SOLID LIQUID GAS Agitated ball milling Sol gel Chemical vapour deposition Lithography Co-precipitation Laser ablation Solvothermal synthesis Flame pyrolysis Biomimetic synthesis Inert gas condensation Microemulsions Sputtering Sonochemical synthesis
4. 4. Agitated ball mill 80% of glass beads or steel balls of size 100 m to several mm Agitator shaft runs along the axis of mill Rotates with speed of 4 -20 m/s The suspension is forced through the mill through a pump S. Bernotat, K. Schnert, in Ullmanns Encyclopedia of Industrial Chemistry, W. Gerhartz, B. Elvers, M. Ravenscroft, J.F. Rounsaville, G. Schulz (Eds.), Vol. B2, 5th Edition, VCH, Weinheim, 1988, p. 5-1.
5. 5. Sol gel synthesis Hiroki Nagai and Mitsunobu Sato (2012) Heat Treatment in Molecular Precursor Method for Fabricating Metal Oxide Thin Films; ISBN 978-953-51-0768-2
6. 6. Solvothermal Precursors are kept at the lower part of the autoclave. heated in order to create two temperature zones nutrient dissolves in the hotter zone and the saturated aqueous solution in the lower part cooler and denser solution in the upper part becomes supersaturated due to reduction in temperature and crystallization sets in.
7. 7. Chemical vapour deposition One or more volatile precursors which react and decompose on the substrate surface Volatile by-products are removed by gas flow Silicon films on titanium carbide or nitride. Silicon dioxide, aluminium oxide www.nppt.uni-due.de/research/nanoparticles-and-nanomaterials/synthesis-and-in- situ-process-anlysis-cvs-ams/
8. 8. Laser ablation Removing material from a solid surface by irradiating it with a laser beam At low laser flux, the material is heated by the absorbed laser energy and evaporates or sublimates At high laser flux, the material is converted to a plasma Gas condensation to produce nano-particles of metal, metal oxides and metal carbides Figure : www.corelase.fi/index.php?id=28
9. 9. REFERENCES Hiroki Nagai and Mitsunobu Sato (2012) Heat Treatment in Molecular Precursor Method for Fabricating Metal Oxide Thin Films; ISBN 978-953- 51-0768-2 www.nppt.uni-due.de/research/nanoparticles -and-nanomaterials/synthesis-and-in-situ- process-anlysis-cvs-ams Synthesis and characterization of nanomaterials; P. Saravanan, R. Gopalan, and V. Chandrasekaran. Defence Science Journal, Vol. 58, No. 4, July 2008, pp. 504- 516