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Displaying 1026 - 1050 of 1926

Interfacial effects on droplet dynamics in Poiseuille flow

April 12, 2011
Author(s)
Jonathan T. Schwalbe, Frederick R. Phelan Jr., Petia Vlahovska, Steven D. Hudson
Interfacial rheology governs many properties of emulsions, and here we report theory that accounts for and measure surface viscous and elastic forces. Stokes flow is assumed in bulk phases and a jump in hydrodynamic stress at the interface is balanced by

A New Interface Defect Spectroscopy Method

April 11, 2011
Author(s)
Jason T. Ryan, Liangchun (. Yu, Jae Han, Joseph J. Kopanski, Kin P. Cheung, Fei Zhang, Chen Wang, Jason P. Campbell, John S. Suehle, Viniyak Tilak, Jody Fronheiser
A new interface defect spectroscopy method based on variable height charge pumping capable of observing the amphoteric nature of Si/SiO2 interface states in production quality sub-micron devices is demonstrated. It can help to resolve the long standing

Modulus-Driven Differentiation of Marrow Stromal Cells in 3D Is Independent of Cytoskeletal Integrity

April 11, 2011
Author(s)
Carl G. Simon Jr., Kaushik Chatterjee, Sapun Parekh, Sheng Lin-Gibson, Nicole M. Moore, Marcus T. Cicerone, Marian F. Young
Cell functions such as proliferation, migration, and differentiation are key physiological processes that are influenced by the physiochemical extracellular environment. We report on the effect of three-dimensional (3D) scaffold modulus on human bone

Separation of Empty and Water-Filled Single-Wall Carbon Nanotubes

April 11, 2011
Author(s)
Jeffrey A. Fagan, Jeffrey R. Simpson, JiYeon Huh, Jeffrey Blackburn, Larsen A. Brian, Josh M. Holt, Angela R. Hight Walker
The separation of empty and water-filled laser ablation and electric arc synthesized nanotubes is reported. Centrifugation of these large-diameter nanotubes dispersed with sodium deoxycholate using specific conditions produces isolated bands of empty and

Quantification and Compensation of Unintentional Analyte Aggregation in Electrospray Sampling

March 30, 2011
Author(s)
Mingdong M. Li, Suvajyoti S. Guha, Rebecca A. Zangmeister, Michael J. Tarlov, Michael R. Zachariah
Electrospray (ES) sources are commonly used to introduce non-volatile materials (e.g. nanoparticles, proteins, etc.) in to the gas phase for characterization by mass spectrometry and ion mobility. Recent studies in our group using electrospray ion mobility

CONTINUOUS FLOW ENZYME-CATALYZED POLYMERIZATION IN A MICROREACTOR

March 25, 2011
Author(s)
Santanu S. Kundu, Atul S. Bhangale, William E. Wallace, Kathleen M. Flynn, Charles M. Guttman, Richard Gross, Kathryn L. Beers
Enzymes immobilized on solid supports are increasingly used for chemical transformation because the process is greener and sustainable. Here we use microreactors to study enzyme catalyzed ring opening polymerization of -caprolactone to polycaprolactone. A

LABORATORY ACCELERATED AND NATURAL WEATHERING OF STYRENE-ETHYLENE-BUTADIENE-STYRENE (SEBS) BLOCK COPOLYMER: ACCELERATION AND CORRELATION

March 23, 2011
Author(s)
Kar T. Tan, Christopher C. White, David J. Benatti, Deborah S. Jacobs, Donald L. Hunston
Indoor accelerated and outdoor field weathering of styrene-ethylene-butadiene-styrene block copolymer have been studied by Fourier transform infrared (FTIR) spectroscopy. In the indoor accelerated experiments, specimens are exposed to ultraviolet-visible

Effects of Ligand Monolayers on Catalytic Nickel Nanoparticles for Synthesizing Vertically Aligned Carbon Nanofibers

March 16, 2011
Author(s)
Kate L. Klein, Mehmet Sarac, Robert Wilson, Aaron C. Johnston-Peck, Junwei Wang, Ryan Pearce, Anatoli V. Melechko, Joseph B. Tracy
Vertically aligned carbon nanofibers (VACNFs) were synthesized using ligand-stabilized Ni nanoparticle (NP) catalysts and plasma-enhanced chemical vapor deposition. Using chemically-synthesized Ni NPs enables facile preparation of VACNF arrays with

Revealing the Interphase in Polymer Nanocomposites

March 16, 2011
Author(s)
Mauro Zammarano, Paul H. Maupin, Li Piin Sung, Jeffrey W. Gilman, Douglas M. Fox
Morphological characterization of polymer nanocomposites is a fundamental challenge that is complicated by multiple length scales. Here, we report a technique for high-throughput monitoring of interphase and dispersion in polymer nanocomposites based on

Flexure-induced structural and electronic changes in polymer supported membranes of length purified single-wall carbon nanotubes

February 22, 2011
Author(s)
John M. Harris, Ganjigunte R. Iyer, Daneesh O. Simien, Jeffrey Fagan, JiYeon Huh, Jun Y. Chung, Steven Hudson, Jan Obrzut, Jack F. Douglas, Christopher Stafford, Erik K. Hobbie
Thin membranes of length purified single-wall carbon nanotubes (SWCNTs) are uniaxially compressed by depositing them on prestretched polymer substrates. Upon release of the strain, the topography, microstructure and conductivity of the films are

The Role of Service Life Prediction In Sustainability Determinations

February 14, 2011
Author(s)
Christopher C. White, Kar T. Tan, Donald L. Hunston
Sustainability calculations are based on assumptions about the energy required to produce, transport place in-service items. A critical component of these calculations is the expected service life of the material, component or system. Estimates of the

Effect of interfaces and adhesion on the creep compliance of thin polymer coatings

February 13, 2011
Author(s)
Peter M. Johnson, John A. Howarter, Christopher Stafford
Thin film indentation experiments on viscoelastic materials allowed for the deconvolution of the bulk compliance from interfacial responses at the buried interface. This technique could discriminate both large changes in the interfacial strength due to

Manipulation of adhesion via sub-surface patterning

February 13, 2011
Author(s)
John A. Howarter, Peter M. Johnson, Jun Y. Chung, Christopher Stafford
The delamination characteristics of patterned and hierarchical interfaces are of great interest due to the advanced adhesion capabilities found with many biological surfaces. Using nature-inspired design principles, micro- and nanostrucutred surfaces have

Gradient Solvent Vapor Annealing of Block Copolymer Thin Films Using a Microfluidic Mixing Device

February 9, 2011
Author(s)
Kathryn L. Beers, Michael J. Fasolka, Julie N. Albert, Timothy D. Bogart, Ronald L. Lewis, J. Brian Hutchison, Bryan D. Vogt, Thomas H. Epps
Solvent vapor annealing (SVA) with solvent mixtures is a promising approach for controlling block copolymer thin film self-assembly. In this work, we present the design and fabrication of a solvent-resistant microfluidic mixing device to produce discrete

Controlling the Microstructure of Solution-Processible Small Molecules in Thin-Film Transistors through Substrate Chemistry

February 4, 2011
Author(s)
Regis J. Kline, Steven D. Hudson, Xinran Zhang, David J. Gundlach, Andrew Moad, Lee J. Richter, Oana Jurchescu, Thomas Jackson, Sanker Subramanian, John E. Anthony, Michael F. Toney
Solution-processible small molecules have tremendous potential for providing both high charge carrier mobility and low cost processing. This study outlines a detailed microstructural study of the effect of substrate chemistry on fluorinated 5,11-bis

SUSTAINABLE FLAME RETARDANTS: BIO-DERIVED PRODUCTS AS INTUMESCING MATERIALS

February 2, 2011
Author(s)
Mauro Zammarano, Douglas M. Fox, Szabolcs Matko, Takashi Kashiwagi, Jeffrey W. Gilman, Rick D. Davis
Scientists are shifting their attention towards technology sustainability and sustainable materials, specifically in terms of energy and environmental impacts. The flame retardant community is also more concerned about these aspects. The recent banning of

Directed 2D-to-3D pattern transfer method for controlled fabrication of topologically complex three- dimensional nanostructures in silicon

February 1, 2011
Author(s)
Konrad Rykaczewski, Owen J. Hildreth, Ching P. Wong, Andrei G. Fedorov, John H. Scott
A process allowing for control over the 3D motion of catalyst nanostructures during Metal-assisted Chemical Etching by their local pinning prior to etching is developed. Topologically complex 3D structures that are partially located within the etched

Electron Beam Induced Growth of TiO2 Nanostructures

February 1, 2011
Author(s)
Renu Sharma
We report the evolution of TiO2 nanostructures when Au nanoparticles, supported on single crystal TiO2 substrates, were heated in ~2 Torr of flowing O2 in an environmental transmission electron microscope. Nanostructures with different morphologies were

Far Infrared Characterization of Single and Double Walled Carbon Nanotubes

January 17, 2011
Author(s)
Shin G. Chou, Zeeshan Ahmed, Georgy Samsonidze, Jing Kong, Mildred Dresselhaus
Variable temperature high resolution far infrared absorption measurements were carried out for single walled carbon nanotubes samples with different diameter distributions. At a temperature where kBT is significantly lower than the phonon energy, the broad
Displaying 1026 - 1050 of 1926
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