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MSE Seminars

 

Department of Chemical and Environmental Engineering Seminar (in conjunction with the Materials Science & Engineering Program)

Nano-Engineered Materials

Dr. Pulickel M. Ajayan

Department of Materials Science and NanoEngineering Rice University, Houston, Texas,

Friday, March 30th, 2018 12:20 - 1:15 pm
Rec Center 3250

Abstract

The past two decades has belonged to truly innovative discoveries in the area of nanotechnology. Although basic science in the area has progressed significantly, there are still challenges related to engineering and integration of nanomaterials into applications and commercial products. This talk will discuss some of the challenges and opportunities in the field, with particular reference to engineered nanomaterials that include carbon nanostructures, two dimensional materials, and several other nanomaterials and hybrids. Our group has made pioneering contributions to this field in relevance to developing these materials for applications such as energy storage and conversion, catalysis, low power devices, coatings and light-weight materials. Several aspects that include synthesis, characterization and modifications will be explored with the objective of achieving functional nanostructures for future technologies. The intrinsic challenges in the area of nano-engineering will be highlighted, particularly for bottom-up creation of nanostructured materials.

Bio

Dr. Pulickel M. Ajayan, the Benjamin M. and Mary Greenwood Anderson Professor of Engineering, is the founding Chair of the Materials Science and NanoEngineering Department in the Brown School of Engineering at Rice University. Prof. Ajayan started out as a metallurgist, and moved quickly into carbon nanotechnology as his major area of focus, with world-leading research into multi- and single-walled carbon nanotubes - their growth in vertical arrays and their uses in composites and other materials - and in graphene and hybrid carbon nanomaterials. Prof. Ajayan has published one book and 600 journal papers with > 130,000 citations and an h-index of 151, based on ISI database. He has received a number of rewards among which including the 2016 Lifetime Achievement Award in Nanotechnology from the Houston Technology Center, 2016 NANOSMAT Prize, Spiers Memorial Award by the Royal Society of Chemistry (UK), Senior Humboldt Prize, MRS medal, and Scientific American 50 recognition. He has been elected as a fellow of the Royal Society of Chemistry (UK) and other academies, as well as serving as visiting and guest faculty positions across the globe.


 

Materials Science & Engineering Seminar

Characterizing the Age of Ancient Egyptian Manuscripts through microRaman Spectroscopy

Dr. Sarah Goler

Columbia Nano Initiative, Columbia University, New York Email: sg2175@gmail.com

Friday, March 23rd, 2018 2:30 pm 3:25 pm Zimmer 413

Abstract

We have established scientific basis for a new, nondestructive methodology for dating ancient Egyptian papyri based on Raman spectroscopy. Egypt’s dry climate has preserved thousands of handwritten documents which provide insight into ancient cultures, but most of these manuscripts are not dated. Currently, the only scientific method for estimating the date is radiocarbon dating, which is destructive and cannot be used to date the ink separate from the support. In contrast, microRaman spectroscopy, a nondestructive light scattering technique, can distinguish physical and chemical properties of materials. We discovered, for a study of well dated ancient Egyptian papyri covering the date range from 300BCE to 900CE, the Raman spectra (20-40 measurements per manuscript) of black ink all show the spectrum of carbon black characterized by two broad features, the G and D bands indicative of crystalline and amorphous carbon. The G band, 1585cm-1, is a Raman allowed transition arising from the E2g inplane vibration of sp2 bonded carbon. The D band at ~1350cm-1 is a forbidden Raman transition that occurs when the lattice symmetry is broken due to disorder, vacancies, crystalline edges, etc. We observed the spectra exhibit systematic change as a function of manuscript date, unexpected given these papyri span 1,200 years and the fact that each manuscript has a unique provenance, archeological, and storage history. We conclude Egyptian black ink pigments were manufactured using similar processes over this time period. We attribute the systematic changes in Raman spectrum to two concurrent oxidation processes: slow oxidation of crystalline carbon and faster oxidation of amorphous carbon. Oxidative degradation proceeds over time altering the Raman response of the material, providing a direct experimental indicator for manuscript age. This research establishes the basis for a simple, rapid, nondestructive method for dating ancient manuscripts from Egypt as well as the ability to differentiate between modern forgeries and authentic ancient manuscripts. To validate this method we performed a blind study where the scientific team performed the measurements and provided predicted dates without knowing the true dates which were revealed later.

Bio

Sarah Goler completed her undergraduate studies in applied physics at Columbia University's School of Engineering and Applied Science and Mathematics. She went on to complete a PhD in Condensed Matter Physics at the Scuola Normale Superiore di Pisa in Italy where she focused on graphene for hydrogen storage using STM, microRaman and CVD processes. She then continued her studies of carbon while completing a postdoctoral position at Columbia University as a member of the Ancient Ink Laboratory. She won a year-long research scientist fellowship with the Italian Academy at Columbia University in 2014/2015 and won the Dan David Prize for young scholars in 2017.

 

 

Materials Science & Engineering Seminar

Simulating Microstructural Evolution during Metal Additive Manufacturing

Dr. Theron Rodgers

Sandia National Laboratories Email: trodger@sandia.gov

Friday, April 20th, 2018 2:30 pm 3:25 pm Zimmer 413

Abstract

With the rapid growth of additive manufacturing, rapid solidification phenomena have become increasingly important in the materials community. Recently, we have introduced a novel Monte Carlo-based method of simulating microstructural evolution during process such as additive manufacturing, welding, and thin film solidification. Here, we will discuss recent work with the model including coupling it to thermal conduction simulations, incorporating crystallographic texture, and using synthetic microstructures in simulations of mechanical behavior.

Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

 

Materials Science & Engineering Seminar

Closed-Loop Research and Development of Gas Atomization and Selective Laser Melting for Additive Manufacturing of Metallic Alloys

Dr. Yongho Sohn

Professor, Department of Materials Science and Engineering University of Central Florida, Orlando, FL, USA
Email: Yongho.Sohn@ucf.edu

Friday, April 13th, 2018 2:30 pm 3:25 pm Zimmer 413

Abstract

Additive manufacturing of metallic alloys is emerging as a disruptive technology to produce net- shape components with nearly unlimited geometrical complexity and customization. This technology also represents an opportunity to design new and modified alloys that can desensitize inherent process variables and take advantage of thermo-kinetic environments associated with additive manufacturing. In this presentation, in-laboratory, hands-on, closed-loop research capability of gas atomization and selective laser melting for alloy development established at UCF will be introduced. Exploration and optimization of process parameters will be documented for gas atomization (e.g., flow rate, atomizing pressure, melt temperature and orifice temperature) and selective laser melting (e.g., laser power, scanning speed, hatch spacing and slice thickness) using microstructure and mechanical properties. Demonstrative results from commercially available and new/modified Al-, Ni-, and Fe-alloys will be discussed to identify scientific understanding required to mature additive manufacturing technology including solidification, micro-segregation, homogenization, and precipitation via multicomponent phase equilibria and diffusion.

Bio

Dr. Yongho Sohn is a Pegasus Professor of Materials Science and Engineering, and Associate Director for Materials Characterization Facility (MCF) at University of Central Florida. MCF is a FL-state user facility for academics and industry with over $20M in analytical instrumentation and 3 full-time staff engineers. He received his B.S. with honors and M.S. from Worcester Polytechnic Institute, Worcester, MA in mechanical and materials engineering, respectively. He graduated in 1999 with a Ph.D. in materials science and engineering from Purdue University and spent two years as a post-doctoral research scholar at the University of Connecticut. He joined University of Central Florida in 2001 as an assistant professor. His research and teaching interests includes microstructural analysis and control, multicomponent intrinsic and

interdiffusion in multiphase alloys, powder processing and additive manufacturing, thermal barrier coatings and other protective metallic/ceramic coatings, and light-weight metallic alloys and metal-matrix composites. He has published 8 book chapters, over 140 journal papers and 60 proceedings papers. He gave over 400 presentations including 100 invited lectures at conferences around the globe. He is a Fellow of ASM International (FASM), recipient of NSF CAREER Award (2003), Outstanding Materials Engineer Award from Purdue University (2016), UCF’s 2017, 2012 and 2006 research incentive awards, UCF’s 2007 and 2013 teaching incentive award. He is an associate editor for Journal of Phase Equilibria and Diffusion and a member of editorial board for Metallurgical and Materials Transactions. He has supervised to completion, 11 Ph.D. students, 29 M.S. students and 8 post-doctoral scholars, and currently supervises 4 Ph.D. students, 1 research associate, and 4 undergraduate research assistants. Details on his research and teaching activities can be found at http://mse.ucf.edu/sohn.