FOCUS ON NANOMANUFACTURING Synthesis and post-processing of nanomaterials using microreaction technology Chih-Hung Chang Æ Brian K. Paul Æ Vincent T. Remcho Æ Sundar Atre Æ James E. Hutchison Received: 29 November 2007 / Accepted: 24 December 2007 Ó Springer Science+Business Media B.V. 2008 Abstract A critical barrier to the routine use of nanomaterials is the tedious, expensive means of their synthesis. Microreaction technology takes advantage of the large surface area-to-volume ratios within microchannel structures to accelerate heat and mass transport. This accelerated transport allows for rapid changes in reaction temperatures and concentrations leading to more uniform heating and mixing which can have dramatic impacts on macromolecular yields and nanoparticle size distributions. Benefits of mi- croreaction technology include higher yield and reactant conversion, better energy efficiency and less by-product generation. Microreactors can help min- imize the environmental impact of nanoproduction by enabling solvent free mixing, integrated separation techniques and reagent recycling. The possibility of synthesizing nanomaterials in the required volumes at the point-of-use eliminates the need to store and transport potentially hazardous materials and pro- vides the flexibility for tailoring complex functional nanomaterials. Recognizing these benefits for nano- synthesis, continuous flow microreactors have been used by several research groups to synthesize and characterize nanomaterials. An overview of these efforts and issues related to scale up and other post synthesis processes such as separation and deposition are presented in this paper. Keywords Microreactors  Microreaction technology  Scale up  Nanoparticles  Dendrimers  Production  Separation  Deposition  Nanomanufacturing Introduction Microscale process engineering is the science of conducting chemical or physical processes (unit operations) inside small volumes, typically inside channels with diameters of less than 1 mm (micro- channels) or other structures with sub-millimeter dimensions. These processes are usually carried out as continuous production, compared to batch produc- tion, with the potential to make microscale process C.-H. Chang (&) School of Chemical, Biological and Environmental Engineering, Oregon State University, Corvallis, OR 97331, USA e-mail: changch@engr.orst.edu B. K. Paul  S. Atre School of Mechanical, Industrial and Manufacturing Engineering, Oregon State University, Corvallis, OR 97331, USA V. T. Remcho (&) Department of Chemistry, Oregon State University, Corvallis, OR 97331, USA e-mail: vincent.remcho@oregonstate.edu J. E. Hutchison Department of Chemistry, Materials Science Institute, University of Oregon, Eugene, OR 97403, USA 123 J Nanopart Res DOI 10.1007/s11051-007-9355-y