Tag Archives: Fall 2009

Synthesis of Boron Nitride Nanotube on Substrates and Its Superhydrophobicity

Friday, November 20, 2009 3:30 – 3:50 pm
Room 610, M&M Building

Chee Huei Lee
Graduate Student
Department of Physics
Michigan Technological University

Abstract

Boron nitride nanotubes (BNNTs) are wide bandgap semiconductors (theoretical value of ~5.5eV), in which the bandgap is insensitive to the number of walls, diameters as well as chiralities.They are potential useful in deep-UV optoelectronic devices, high temperature electronic,nanocomposites, clinical boron neutron capture therapy, and so on. However, the synthesis of BNNTs is challenging, compared to that of carbon nanotubes (CNTs).The chemistry of the process is more involved and usually requires high temperature. We showthat effective growth of high quality BNNTs can be obtained in our lab by a simple thermalchemical vapor deposition technique (Thermal-CVD) at 1200°C, with growth vapor trappingapproach. Furthermore, it is found that the BNNT films can achieve superhydrophobic state with the watercontact angle exceeding 150 degree. Some experiment results will be presented during theseminar. Since BNNTs are chemically inert and resistive to oxidation up to 1000°C, itssuperhydrophobic behavior could be potentially useful as self-cleaning, insulating andanticorrosive coating under rigorous chemical and thermal conditions.


Aging-Stabilization of Ferroelectric Domains due to ShortRange Ordering of Charged Point Defects

Friday, November 20, 2009 3:05 – 3:25 pm
Room 610, M&M Building

Tianle Cheng
Graduate Student
Department of Materials Science and Engineering
Michigan Technological University

Abstract

Phase field simulation, thermodynamic analysis and ionic interaction analysis arerespectively conducted to study the aging-stabilization effect in dopedferroelectrics. Phase field model takes into account various energetic contributionsinvolved in domain aging phenomenon, including chemical, domain wall,electrostatic and elastostatic energies, as well as internal bias electric fieldassociated with the short-range ordering of charged point defects. The internalelectric field strength is estimated by computer simulation. Clausius-Clapeyrontype thermo- dynamic analysis of field-induced ferroelectric phase transition isused to evaluate aging-associated internal electric field magnitude from availableexperimental data, which is in agreement with the computer simulation. Fromatomic level, ionic interaction analysis on charged point defect configurationsshows that defect dipole-dipole interaction may play important role in theferroelectric aging phenomenon.

Materials and Life Science Investigations in Atomic Force Microscopy

Friday, November 13, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Adam Mednick
Veeco Instruments
Santa Barbara, CA

Abstract

Atomic Force Microscopy (AFM) is a versatile technique due to its ability to characterizematerials ranging from biopolymers to semiconductor surfaces.  Besides the ability to studysurfaces at the nanometer scale, AFM can be used to study materials properties of the samplesby related techniques that make up the field of Scanning Probe Microscopy (SPM).  There areseveral techniques for electrical characterization to study electrostatic fields, current flow, andpiezoelectric behavior of the materials.  Properties such as elastic modulus, adhesion, andenergy dissipation can be studied by conducting force measurements during TappingModeimaging using the harmonic oscillation behavior of the cantilever, forming a new techniquecalled HarmoniX.  AFM technology is also commonly used to manipulation features at thenanometer scale.  Life science applications consist of studying macromolecules up to live cells.Cellular studies often consist of integrating the AFM with fluorescence and confocal microscopywhich can be integrated with the system to direct the AFM data collection.  This presentation willprovide an overview of these and other applications of AFM to provide a view of how thetechnique is used currently, and where it is progressing in the future.

Biography

Adam Mednick is a Veeco Applications Engineer, based in Santa Barbara, CA.Adam has spent the last 3 years in the AFM applications group, where he has played asignificant role in developing the Dimension ICON, Veeco’s new flagship research AFMplatform.  He has a broad range of practical experience with various measurements that arepossible with AFM, especially material and electrical characterization techniques.  Prior tojoining Veeco, Adam performed his graduate research at Lawrence Livermore National Lab inthe Center for Micro and Nano Technologies.  He received his M.S. in Electrical Engineeringand B.S. in Physics and Electrical Engineering from Cal Poly, San Luis Obispo, and his MBAfrom Pepperdine University’s Graziadio School of Business.


Real-Time Electro-Mechanical Coupling in One-Dimensional Materials

Friday, November 6, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Prof. Reza Shahbazian-Yassar
Department of Mechanical Engineering Engineering Mechanics
Michigan Technological University

Abstract

Nanomaterials including nanotubes and nanowires are the smallest buildingblocks for future small-scale electronics, and energy conversion technologies.Therefore it is very important to understand the intrinsic physical and mechanicalproperties of these low-dimensional nanostructures. At Michigan Tech, through arecent NSF-MRI grant we have gained access to an advanced characterizationtechnique that enables simultaneous electrical, mechanical, and structuralmonitoring of nano-scale materials. This talk gives an overview on some of thecurrent research of the PI on organic and inorganic nanowires and nanotubesused for solar cells, nanogenerators, nanoelectronics, and high-strengthbiocomposites.

Biography

Dr. Reza Shahbazian-Yassar received his PhD from Washington State University in2005. He is currently an assistant professor and adjunct assistant professor at the departmentsof Mechanical Engineering-Engineering Mechanics and Materials Science and Engineering atMichigan Tech. He joined Michigan Tech in fall 2007. Prior to his position at Tech, he was apost-doctorate research associate at the Multiscale Modeling group of Prof. Mark Horstemeyerat Mississippi State University. Dr. Yassar’s research is being supported through NSF, DOE,Michigan Space Grant Consortium, Michigan Tech Research Excellence Fund, and MuSTI.


Nano-Bio-Hybrid Optical Protein for Sensing and Photon Harvesting

Friday, October 23, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Prof. Craig Friedrich
Department of Mechanical Engineering Engineering Mechanics
Michigan Technological University

Abstract

The integration of opto-electrical transduction protein with inorganicnanomaterials, CMOS, and single electron transistors opens up many possibilitiesfor bio-nano-hybrid materials applications in sensing and photon harvesting.  Thetalk will provide results on integrating the protein bacteriorhodopsin with micro andnanoelectronics, quantum dots, and sensing protein to form a bio-nano-hybridsensing platform technology. Additionally, recent work is underway to investigatethe applicability of bacteriorhodopsin coupled with nanostructures of variousmaterials for use as a photon harvester, possibly to power nanosensing systems,and initial results will be shown.

Biography

Prof. Craig Friedrich is Associate Chair and Director of Graduate Studies of theDepartment of Mechanical Engineering- Engineering Mechanics at Michigan TechnologicalUniversity.  He also directs the Multi-Scale Technologies Institute and is the Robbins Professorin Sustainable Design and Manufacturing.  His PhD is from Oklahoma State University.  In theearly 1990s, Dr. Friedrich helped pioneer the field of mechanical micromachining, particularlymicromilling, by creating (at the time) the world’s smallest milling tools and demonstrating themilling process to make micron-scale features with sub-micron tolerances.  He alsodemonstrated mechanically machined x-ray masks and gray-scale x-ray lithography usingmicromilled masks.  Recently, he is working in the area of bio-nano-hybrid materials for a varietyof sensing and energy applications.


Mapping Charge-Mosaic Surfaces in Electrolyte Solutions Using Atomic Force Microscopy

Friday, October 16, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Jaroslaw Drelich
Department of Materials Science and Engineering
Michigan Technological University

Abstract

Colloidal forces dominate stability of particles in aqueous environment and often dictatestrategies in wet processing of minerals and other materials. The most successful approach tothe problem of net interactions between two interfaces in these systems was proposed byDerjaguin, Landau, Verwey and Overbeek and is known as the DLVO theory. This theory treatsthe total interaction force between two surfaces in a liquid medium as an arithmetic sum of twocomponents: van der Waals and electrostatic (electrical double layer) forces. The DLVO theoryhas been used as a mean-field approach, where only one surface potential and one Hamakerconstant are used to describe the colloidal forces. On a contrary, a vast majority of surfaces ofparticles and materials in technological systems are of a heterogeneous (mosaic) naturecomposed of microscopic and sub-microscopic domains of different surface characteristics. Inthese systems, the interactions can be dominated by heterogeneities rather than averagesurface character. Attractions can be stronger, by orders of magnitude, than would be expectedfrom the classical mean-field model when area-averaged surface charge or potential isemployed. To detect heterogeneities in surface charge, analytical tools which provide accurateand spatially resolved information about material surface potential—particularly at microscopicand sub-microscopic resolutions—are needed.

A novel AFM-based technique for mapping surface charge domains on heterogeneous surfaceswas recently introduced by our research team. It relies on recording colloidal force curves overmultiple locations on the substrate surface using small probes. The experiments are conductedin electrolyte solutions with different ionic strengths and pH values. The force-distance curvemeasurements are carried out stepwise across phases of different surface characteristic.Surface charge densities and surface potentials are then calculated by fitting the experimentaldata with a DLVO theoretical model. The surface charge characteristics of the heterogeneoussubstrate are determined from the recorded colloidal force curves, allowing for the surfacecharge variation to be mapped. In this presentation, the AFM technique will be briefly introducedand its use in determination of local surface charges for a multi-phase rock and bitumen will bereviewed.


Effect of Doped Transition Metals on Hydrogen Interaction in Complex Hydrides

Friday, October 2, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Qingfeng Ge
Department of Chemistry and Biochemistry
Southern Illinois University
Carbondale, IL

Abstract

Light-metal complex hydrides have attracted great attention as potential hydrogen-storage materials.Over the past decade, tremendous efforts have been put into improving their storage capacity andadsorption/desorption kinetics. While significant progress has been made in engineering the catalystsand preparing the advanced storage materials over the past few years, hydrogen storage remains amajor obstacle in transition to a hydrogen economy. Developing a practical hydrogen storage materialrequires a detailed understanding of the intrinsic hydrogen-metal bond strength and the effect of localreaction environment. In this talk, I will report the results of our extensive density functional theory studyof the hydrogen storage properties of transition metal (TM)-doped NaAlH4. In particular, we found that thedoped transition metal form a surface interstitial complex structure with three neighboring AlH4- groups.We discovered that this complex played important roles in hydrogen release/uptake from TM-dopedNaAlH4. Our analysis demonstrated that the early TMs are more effective to reduce the hydrogendesorption energy as well as activate the H—H bond than the late TMs. The hydrogen release/uptakeprocess can be viewed as an exchange of σ-bond ligands (H—H for Al—H) by TM on the basis of thecomplex through a metathesis process involving σ-bonds. The balanced ability of accepting electrons inand backdonating electrons from the d orbitals of the early TMs made them ideal candidates as catalystsfor hydrogen release/uptake. We extended the study to Ti-doped LiBH4 and found that both the localcomplex structure and the effect of doped Ti are different from that in NaAlH4.

Biography

Dr. Qingfeng Ge is an Associate Professor in the Department of Chemistry and Biochemistry, SouthernIllinois University Carbondale. He is one of the 70 recipients of the Presidential Hydrogen Fuel Initiative awardsnationwide in 2005. A main thrust of his research is using modeling/simulation to address materials issues relatedto energy and environment. Dr. Ge holds M.Sc and Ph.D degrees in Chemical Engineering from Tianjin University,China. He worked as a Postdoctoral scholar in Copenhagen University, Denmark, Cambridge University, U.K. andUniversity of Virginia before joining SIUC. His experiences ranged from experimental characterization and kineticsmodeling of catalysts to first principles based simulations of various materials. He authored/coauthored more than70 journal papers, including those in Science, the Journal of American Chemical Society, and Physical ReviewLetters.


Materials Design Education

Friday, September 25, 2009 12:00 – 1:00 pm
Room U113, M&M Building

G.B. Olson
Northwestern University & QuesTek Innovations LLC

Abstract

A novel integration of design into the undergraduate materialscurriculum has beenunder development for the past 15 years at Northwestern.The Bodeen-LindbergMaterials Design Studio serves as a central teaching facility for computationalMSE in the curriculum. Software tools introduced throughout core courses areintegrated in a required junior-level Materials Design course. Through anintegration of education activities of our Design Institute with funded designresearch activities of the Materials Technology Laboratory, coaching by graduatestudents and post-doctoral researchers facilitates cross-disciplinary concurrentcomputational engineering of materials and structures in engineering schoolwide”institute projects” involving multidisciplinary undergraduate teams spanningfreshman to senior level. Project examples include “Civil Shield” addressingmaterials and structures for civilian anti-terrorism bomb mitigation, and “SmartStent” integrating high-performance shape memory alloys in endovascular stentdesigns.


Computational Materials Scieneering

Friday, September 25, 2009 3:00 – 4:00 pm
Room 610, M&M Building

G.B. Olson
Northwestern University & QuesTek Innovations LLC

Abstract

The numerical implementation of established materials science principles in the form ofpurposeful engineering tools has brought a new level of integration of the science andengineering of materials. Parametric materials design integrating materials science, appliedmechanics and quantum physics within a systems engineering framework has brought a firstgeneration of designer “cyberalloys” that have now entered successful commercial applications,and a new enterprise of commercial materials design services has steadily grown over the pastdecade. The success of materials design established a basis for the recent DARPA-AIMinitiative which broadened computational materials engineering to address acceleration of thefull materials development and qualification cycle. As the central engine of the AIMmethodology, the PrecipiCalc microstructural simulator has demonstrated both acceleratedthermal process optimization at the component level and the effective forecast of manufacturingvariation with efficient fusion of minimal datasets. A new level of science-based modelingaccuracy is being achieved under the ONR/DARPA “D3D” Digital Structure consortium using asuite of advanced 3D tomographic characterization tools to calibrate and validate a set of highfidelity explicit 3D microstructural simulation tools spanning the hierarchy of microstructuralscales.


A New Model for the Critical Thickness of Metallic Amorphous Thin Films

Friday, September 18, 2009 3:00 – 4:00 pm
Room 610, M&M Building

Jong K. Lee
Department of Materials Science and Engineering
Michigan Technological University

Abstract

A new model for the critical thickness of amorphous metallic thin films isproposed in which the surface free energy difference, Δγ, equals γCV +γCA – γAV, where γCV is the crystalline-vapor, γCA the crystallineamorphous, and γAV, the amorphous-vapor interface free energy. It ispredicated upon experimental evidence that non-epitaxial film growthdue to large atomic-size difference dictates one or two amorphousatomic layers in contact with the substrate phase. Consequently, themodel does not require hardly-accessible film-substrate interface freeenergies in predicting the critical thickness for amorphous-crystallinetransition.

Read more here.