Armando D. Urbina1+, Hari Sridhara1+, Alexis Scholtz2+, Andrea M. Armani1,2,3 *1- Mork Family Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089, USA2- Alfred E. Mann Department of Biomedical Engineering, University of Southern California, Los Angeles, CA 90089, USA3- Ellison Institute of Technology, Los Angeles, CA 90064, USA+ These authors contributed equally.The following laboratory procedure provides students with a hands-on experience in nanomaterials chemistry and characterization. This three-day protocol is easy to follow for undergraduates with basic chemistry or materials science backgrounds and is suitable for inclusion in upper division courses in inorganic chemistry or materials science. Students use air-free chemistry procedures to synthesize and separate iron oxide magnetic nanoparticles and subsequently modify the nanoparticle surface using a chemical stripping agent. The morphology and chemical composition of the nanoparticles are characterized using electron microscopy and dynamic light scattering measurements. Additionally, magnetic characterization of the particles is performed using an open-source (3D-printed), inexpensive magnetophotometer. Possible modifications to the synthesis procedure including the incorporation of dopants to modify the magnetic response and alternative characterization techniques are discussed. The three-day synthesis, purification, and characterization laboratory will prepare students with crucial skills for advanced technology industries such as semiconductor manufacturing, nanomedicine, and green chemistry.
3f, the particles synthesized by either the students or the laboratory assistant exhibit a clear positive magnetic response when in the presence of the permanent magnetic, indicating a positive magnetic susceptibility value. Journal of Chemical Education 9/18/22 Page 9 of 15 Figure 3. Iron oxide nanoparticle (a-b) SEM image, (c-d) DLS data, (e-f) magnetic response data from the MAP system and ethanol control. Data taken with particles made by the student volunteers following the procedure are shown in panels (a), (c), and (e). Data taken with particles made by graduate assistant are shown in panes (b), (d), and (f).
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SUMMARY AND CONCLUSION In summary, we have detailed a research-based, three-day, advanced undergraduate laboratory protocol which includes the synthesis of iron oxide magnetic nanoparticles, modification of the surface coating, and characterization of the particle properties. The experiments can easily be modified based on available equipment. They are designed to combine principles from chemistry, materials science, and physics to expose students to interdisciplinary research and modern instrumentation while utilizing inexpensive reagents and commonly accessible characterization techniques. They also serve as a bridge, connecting seemingly disparate coursework. While this 3-day laboratory experiment was Journal of Chemical Education 9/18/22 Page 10 of 15 piloted with a cohort of undergraduate students, it could also be suitable for a graduate student experimental methods course. ASSOCIATED CONTENT Supporting Information The Supporting Information is available on
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1021/acs.jchemed.XXXXXXX. Instructor Manual (PDF, DOCX): Detailed protocols, trouble-shooting suggestions, materials and equipment tables, and educational assessment. Student Manual (PDF, DOCX): Step-by-step protocols and materials and equipment tables Student Assessment (PDF, DOCX) and Solutions (PDF, DOCX): Suggested pre-laboratory exercises to enrich student learning and solutions. AUTHOR INFORMATION Corresponding Author: Andrea M. Armani Email: aarmanieit.org Armando Urbina: 0000-0003-3036-4991 Hari Sridhara: 0000-0001-8548-0581 Alexis Scholtz: 0000-0001-6275-0622 Andrea M. Armani: 0000-0001-9890-5104 ACKNOWLEDGMENTS The authors would like to thank Jack G. Paulson, Kylie J. Trettner, Marko Lili, Patrick Saris, Sydney Fiorentino, Victoria Nuez (University of Southern California) for contributions to the refinement of the iron oxide nanoparticle protocol. This work was supported by the Office of Naval Research (N00014-
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22-1-2466, N00014-21-1-2044), the National Science Foundation (DBI-2222206), and the Ellison Institute of Technology, LLC. A. D. Urbina is supported by a National Science Foundation Graduate Research Fellowship. H. Sridhara is supported by the University of Southern California Center for Undergraduate Research in Viterbi Engineering and Provost Undergraduate Research Fellowships. Journal of Chemical Education 9/18/22 Page 11 of 15 A.M.A. serves as the Senior Director of Engineering and Physical Sciences for the Ellison Institute of
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