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NIST Authors in Bold

Displaying 1151 - 1175 of 1938

Methods for TEM analysis of NISTs SWCNT SRM

March 25, 2010
Author(s)
Roy H. Geiss, Elisabeth Mansfield, Jeffrey A. Fagan
The National Institute of Standards and Technology (NIST) is developing a series of single-walled carbon nanotube, SWCNT, reference materials, RMs, to provide researchers with well characterized materials for their applications. The SWCNT reference

Compressive stress effect on the radial elastic modulus of oxidized Si nanowires

March 23, 2010
Author(s)
Gheorghe Stan, Sergiy Krylyuk, Albert Davydov, Robert F. Cook
Detailed understanding and optimal control of the properties of Si nanowires are essential steps in developing Si nanoscale circuitry. In this work, we have investigated mechanical properties of as-grown and oxidized Si nanowires as a function of their

Harnessing Wrinkle Delamination Mechanics to Measure and Pattern Polymer Coatings

March 21, 2010
Author(s)
Adam J. Nolte, Jun Y. Chung, Christopher Stafford
Compressive stresses in stiff polymer coatings can give rise to surface instabilities in which the coating adopts a sinusoidally wrinkled morphology with a dominant wavelength, d, as displayed in Figure 1a. Such instabilities are generally observed for

Influence of molecular mass on the modulus of thin polystyrene films

March 21, 2010
Author(s)
Jessica M. Torres, Christopher Stafford, Bryan D. Vogt
In this work, we examine the influence of relative molecular mass (Mn, or the number average molecular mass) of PS on the thickness-dependent moduli using a wrinkling based instability of a stiff film on an elastic substrate. This wrinkling based metrology

Characterization of Soluble Anthradithiophene Derivatives

March 18, 2010
Author(s)
Brad Conrad, Calvin Chan, Marsha A. Loth, John E. Anthony, David J. Gundlach
We will discuss the growth and electrical measurements of a newly developed, partially fluorinated anthradithiophene (F-ADT) derivative with tert-butyldiphenylsilyl (TBDMS) side groups. Single crystals of the material can be readily grown and device hole

Matrix Relaxation After Fracture In A Toughened Epoxy

March 3, 2010
Author(s)
Aaron M. Forster, Aurelien Blond, Donald L. Hunston
The inclusion of phase-separated rubber particles in a brittle thermoset matrix has been shown to increase the Mode I fracture energies for a wide range of model and commercial adhesives. Our recent efforts combine these two approaches by comparing the

Thin film morphology of organic electronic materials

March 1, 2010
Author(s)
Xinran Zhang, Steven Hudson, Dean DeLongchamp, David J. Gundlach
Organic electronic materials are desired for low-cost printed circuits. As expected, the microstructure of these materials is crucial for their performance, such as charge-carrier mobility. These materials typically comprise anisotropic molecules, and the

Little Things Mean a Lot: Water and the Adhesive Bond

February 21, 2010
Author(s)
Donald L. Hunston, Kar T. Tan, Bryan D. Vogt, Sushil K. Satija, Cyril Clerici, David E. White
The ability of water to dramatically weaken many types of adhesive bonds has been widely studied. One surprising result is the existence of a critical moisture level in the bond. Above this level the strength drops to very low values. Numerous studies have

Roles of Adhesive and Interfacial Properties on Humidity-induced Failure

February 21, 2010
Author(s)
Kar T. Tan, Christopher C. White, Donald L. Hunston, Kristen L. Steffens, Hatlee Timothy, Kristen Hamilton, Vogt D. Bryan
Adhesion loss due to moisture is a fundamental problem in a large diversity of industries ranging from microelectronics and automotive to aerospace. This study investigates the durability of model adhesive joints consisting of a homologous series of poly(n

Challenges in Continuum Modeling of Intergranular Fracture

February 11, 2010
Author(s)
Valerie R. Coffman, James P. Sethna
Intergranular fracture in polycrystals is often simulated by finite elements coupled to a cohesive-zone model for the interfaces, requiring cohesive laws for grain boundaries as a function of their geometry. We discuss three challenges in understanding

Electrically-stimulated gradients in water and counterion concentrations within electroactive polymer actuators

February 1, 2010
Author(s)
Jong Keun Park, Paul J. Jones, Chris Sahagun, Kirt A. Page, Daniel S. Hussey, David L. Jacobson, Sarah E. Morgan, Robert B. Moore
While ionic polymer metal composites (IPMCs) have been studied for more than 10 years, the specific actuation mechanism is still unclear. In this work, neutron imaging, applied potential (AP) and current sensing (CS) atomic force microscopy (AFM) methods

Gradient and Microfluidic Library Approaches to Polymer Interfaces

January 1, 2010
Author(s)
Michael J. Fasolka, Christopher M. Stafford, Kathryn L. Beers
We present and overview of research conducted at the National Institute of Standards and Technology aimed at developing combinatorial and high throughput measurement approaches to polymer surfaces, interfaces and thin films. Topics include, 1) the

IMMOBILIZED ENZYME CATALYZED POLYMERIZATION REACTIONS IN MICROREACTORS

January 1, 2010
Author(s)
Santanu S. Kundu, Atul Bhangale, William E. Wallace, Kathleen M. Flynn, Richard Gross, Kathryn L. Beers
Application of microreactor technologies enable improved safety, selectivity and yield in a range of chemical reactions in addition to new measurement methods that are often faster, cheaper and more accurate than traditional methods. In this study we have

IMPACT OF IMMOBILIZATION SUPPORTS FOR POLYESTERS SYNTHESIS ACTIVITY OF CANDIDA ANTARTICA LIPASE B

January 1, 2010
Author(s)
Atul Bhangale, Santanu S. Kundu, Wenchun Xie, William E. Wallace, Kathleen M. Flynn, Kathryn L. Beers, Richard Gross
Epoxy functionalized supports are known to be suitable for industrial-scale immobilization of enzymes for biocatalysis. However, chemistry across these epoxy groups is known to affect the catalytic performance of the enzymes.In order to achieve a balance
Displaying 1151 - 1175 of 1938
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