Spring 2015 Seminars
|January 12, 2015||GPS 101||Kent Ridl|
|January 19, 2015||Martin Luther King, Jr. Day|
|January 26, 2015|
The Emerging Role of Network Analysis in Physics Education
|February 2, 2015||Void formation in crosslinked polymer networks||Aaron Feickert|
|February 9, 2015||How Fluid Flow Affects Phase-Separation Front Formed Morphologies||Eric Foard|
<Presidents' Day> Infectious diseases, auto-immune diseases, and opportunities for biophysics
|February 23, 2015||Nanoparticles at an Air-Water Interface:a Mixed Boundary Value Problem||Guilherm Bossa|
|March 2, 2015||APS March Meeting|
|March 9, 2015||A Bias-Free Algorithm for Diffusion-Limited Aggregation||Yen Lee Loh|
|March 16, 2015||Spring Break!!|
|March 23, 2015||Neutrinos: From Cosmic Rays and Accelerators to Old Iron Mines and the Fate of the Universe||Alec Habig|
|March 30, 2015||TBA||Alex Waters|
|April 1, 2015||<Special Day and Location!!>Structure, Dynamics and Properties of Block Polymer Dispersions||Frank S. Bates|
|April 6, 2015||Spring Recess|
April 13, 2015
|April 20, 2015||TBA||Alfredo Alexander-Katz|
|April 24, 2015||<Special Day!!>TBA||Christos Likos|
|April 27, 2015||John Harris|
|May 4, 2015||TBA||Jessica Striker|
|May 5, 2015||<Special Day and Location!!>A Robust Nonlinear Block Copolymer Nanoreactor-Based Strategy to Monodisperse Hairy Nanocrystals with Precisely Controlled Dimensions, Compositions and Architectures||Zhiqun Lin|
|May 11, 2015||Exam Week!|
Neutrinos: From Cosmic Rays and Accelerators to Old Iron Mines and the Fate of the Universe
Department of Physics,
Minnesota State University, Duluth.
Monday, March 23, 2015, 3:00-4:00pm, Refreshments at 2:30.
221 South Engineering
Neutrinos are fundamental particles which interact only weakly with other matter, and had been thought to be massless. However, if they did have some non-zero mass, they would change flavors as they fly along. This talk follows the search for these "oscillations" in neutrinos coming from cosmic-ray interactions with the Earth's upper atmosphere starting with the Super-Kamiokande experiment. The MINOS experiment is making precise measurements of the phenomenon by creating an intense, well-understood neutrino beam at Fermilab (near Chicago) and observing it 735km away at the Soudan Mine in Northeast Minnesota. The new NOvA experiment has started observations of the same beam in a different way, to help nail down more subtle neutrino changes. Lastly, the implications of a whole lot of slightly-massive neutrinos sloshing around the universe are discussed.
Structure, Dynamics and Properties of Block Polymer Dispersions
Dr. Frank S. Bates
Regents Professor and Head, Department of Chemical Engineering and Materials Science, University of Minnesota
<Special Time!!>Wednesday, April 1, 2015, 3:00-4:00pm (refreshments served 2:30).
<Special Location!!>271 Batcheller Technology Center
Block copolymers belong to a broad class of amphiphilic compounds that includes soaps, lipids and nonionic surfactants. These macromolecules assemble into micelles with molecular dimensions on the order of 5 to 50 nm in size when mixed with excess solvent that preferentially solvates one block type. This presentation will explore two different aspects of block copolymer micelle formation. The fundamental thermodynamic and kinetic factors that control micelle shape and dynamics will be discussed based on small-angle x-ray and neutron scattering (SAXS and SANS) experiments and cryogenic transmission and scanning electron microscopy results. Although the structural features displayed by amphiphilic block copolymers resemble those associated with the self-assembly of lipids and simple surfactants (e.g., spherical and cylindrical micelles and vesicles) a macromolecular architecture leads to remarkably different dynamic properties, linked to a vanishingly small critical micelle concentration. As a consequence, molecular exchange is rapidly extinguished with increasing molecular weight resulting in non-ergotic behavior. These concepts have been exploited in developing a recently commercialized technology that provides immense improvements in the fracture toughness of thermosetting epoxy plastics, which also will be described.
A Robust Nonlinear Block Copolymer Nanoreactor-Based Strategy to Monodisperse Hairy Nanocrystals with Precisely Controlled Dimensions, Compositions and Architecture.
Dr. Zhiqun Lin
Professor, School of Materials Science and Engineering, Georgia Institute of Technology
<Special Time!!> Tuesday, May 5, 2015, 3:00-4:00pm (Refreshments will be served at 2:30).
<Special Location!!>271 Bachellor Technology Center
Nanocrystals exhibit a wide range of unique properties (e.g., electrical, optical, and optoelectronic) that depend sensitively on their size and shape, and are of both fundamental and practical interest. Breakthrough strategies that will facilitate the design and synthesis of a large diversity of nanocrystals with different properties and controllable size and shape in a simple and convenient manner are of key importance in revolutionarily advancing the use of nanocrystals for a myriad of applications in lightweight structural materials, optics, electronics, photonics, optoelctronics, magnetic technologies, sensory materials and devices, catalysis, drug delivery, biotechnology, and among other emerging fields. In this talk, I will elaborate a general and robust strategy for crafting a large variety of functional nanocrystals with precisely controlled dimensions (i.e., plain, core/shell, and hollow nanoparticles) by capitalizing on a new class of unimolecular star-like block copolymers as nanoreactors. This strategy is effective and able to produce organic solvent-soluble and water-soluble monodisperse nanoparticles, including metallic, ferroelectric, magnetic, luminescent, semiconductor, and their core/shell nanoparticles, which represent a few examples of the kind of nanoparticles that can be produced using this technique. The applications of these functional nanocrystals in energy-related applications (i.e., solar cells and photocatalysis) will also be discussed.