U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications

NIST Authors in Bold

Displaying 676 - 700 of 1856

In situ temperature measurements for selective epitaxy of GaN nanowires

February 17, 2014
Author(s)
Kristine A. Bertness, Matthew D. Brubaker, Todd E. Harvey, Shannon M. Duff, Aric W. Sanders, Norman A. Sanford
We demonstrate with spatially resolved, in situ temperature measurements and ex situ reflectance measurements that differences in appearance for masked and unmasked surfaces on patterned growth substrates arise from wavelength-dependent emissivity

Role of salt on adhesion of an epoxy/aluminium (oxide) interface in aqueous environments

February 16, 2014
Author(s)
Christopher C. White, Kar T. Tan, Donald L. Hunston, Justin M. Gorham, Aaron M. Forster, Vogt D. Bryan
The durability of adhesive joints in hostile environments is a major area of concern in structural adhesive bonding. Therefore, understanding the mechanics and mechanisms of degradation of adhesive joints is a key factor for more extensive use in future

Designing High-Performance PbS and PbSe Nanocrystal Electronic Devices through Stepwise, Post-Synthesis, Colloidal Atomic Layer Deposition

February 6, 2014
Author(s)
Soong Ju Oh, Nathaniel E. Berry, Hi-Hyuk Choi, E. A. Gaulding, Hangfei Lin, Taejong Paik, Benjamin T. Diroll, Shinichiro Muramoto, Murray B. Christopher, Cherie R. Kagan
We report a facile, solution based, post synthetic colloidal atomic layer deposition (PS-cALD) process to engineer the surface stoichiometry and therefore electronic properties of lead chalcogenide nanocrystal (NC) thin films. Using the stepwise and

Nanoscale mechanics by tomographic contact resonance atomic force microscopy

January 23, 2014
Author(s)
Gheorghe NMN Stan, Santiago Solares, Bede Pittenger, Natalia Erina, Chanmin Su
We report on a quantifiable depth-dependent contact resonance AFM (CR-AFM) measurements over polystyrene-polypropylene (PS-PP) polymer blends to detail surface and sub-surface features in terms of elastic modulus and mechanical dissipation. The depth

Isolation of Specific Small Diameter Single-Wall Carbon Nanotube Species via Aqueous Two-Phase Extraction

January 21, 2014
Author(s)
Jeffrey A. Fagan, Constantine Y. Khripin, Carlos A. Silvera Batista, Jeffrey R. Simpson, Angela R. Hight Walker, Ming Zheng
Aqueous two-phase extraction (ATPE) is demonstrated to enable isolation of multiple semiconducting and metallic single-wall carbon nanotube species from a small diameter synthetic mixture. Separation by ATPE is rapid and robust, with remarkable tunability

Saponins: A sustainable surfactant. From its microwave-assisted extraction to the synthesis of monodisperse latices

January 21, 2014
Author(s)
Charlene Schnitt, Bruno Grassl, Julien C. Gigault, Vincent A. Hackley, Gaetane Lespes, Jacques Desbrieres, Virginie Pellerin, Stephanie Reynaud
Synthetic surfactants are widely used in emulsion polymerization, but it is increasingly desirable to replace them with naturally derived molecules with a reduced environmental burden. This study demonstrates the use of saponins as sustainable and

Measuring order in regioregular poly(3-hexylthiophene) with solid-state 13C CPMAS NMR

January 10, 2014
Author(s)
Ryan C. Nieuwendaal, Chad R. Snyder, Dean M. DeLongchamp
We report on details of molecular packing in high molar mass poly(3-hexylthiophene) (P3HT) by solid-state 13C {1H} cross-polarization magic angle spinning (CPMAS) NMR measurements. The degree of polymer order was estimated for two films of varied drying

Tailoring the Permselectivity of Water Desalination Membranes via Nanoparticle Assembly

January 6, 2014
Author(s)
Edwin Chan, William Mulhearn, Jung-Hyun Lee, Daeyeon Lee, Christopher Stafford
: Thin film composite membranes can selectively separate mono- and di-valent ions from water via solution-diffusion of each species through a dense but ultrathin, highly crosslinked polymer ‘skin' layer - water is transported across the membrane faster

Tunable electrical conductivity in metal-organic framework thin film devices

January 3, 2014
Author(s)
Albert A. Talin, Andrea Centrone, Alexandra C. Ford, Michael E. Foster, Vitalie Stavila, Paul M. Haney, Robert A. Kinney, Veronika Szalai, Farid El Gabaly, Heayoung Yoon, Francois Leonard, Mark Allendorf
We report a strategy for realizing tunable electrical conductivity in MOFs in which the nanopores are infiltrated with redox-active, conjugated guest molecules. This approach is demonstrated using thin-film devices of the MOF Cu3(BTC)2 (also known as HKUST

Comparison of atom probe compositional fidelity across thin film interfaces

January 1, 2014
Author(s)
Andrew Herzing, Justin G. Brons, Karen T. Henry, Ian M. Anderson, Gregory B. Thompson
A series of Fe/Ni and Ti/Nb multilayers with bilayer repeat distances of approximately 4 nm have been sputter-deposited onto n-doped Si [001] substrates. The films were focus ion beam milled into the required needle-shaped geometry for atom probe analysis

Switching the Adhesive State of Catacholic Hydrogels using Phototitration

November 19, 2013
Author(s)
Evan M. White, Jonathan Seppala, Parker M. Rushworth, Suraj Sharma, Jason Locklin
A polyacrylamide hydrogel system that can be liquefied by remote activation using UV irradiation was investigated as a degradable adhesive. The linear polyacryamide copolymer, formed by conventional free-radical polymerization, contains biomemetic catechol

Isn’t it time to get serious about standards?

November 18, 2013
Author(s)
Kristine A. Bertness
Current methods of composition measurement lack the ability to produce consistent results from laboratory to laboratory and across companies. NIST has developed AlGaAs SRMs to make standardization possible, but the standards need to be used. This opinion

Atom probe tomography evaporation behavior of C-axis GaN nanowires: Crystallographic, stoichiometric, and detection efficiency aspects

November 13, 2013
Author(s)
Norman A. Sanford, David R. Diercks, Brian Gorman, R Kirchofer, Kristine A. Bertness, Matthew D. Brubaker
The field evaporation behavior of c-axis GaN nanowires was explored in two different laser-pulsed atom probe tomography (APT) instruments. Transmission electron microscopy imaging before and after atom probe tomography analysis was used to assist in

Electron Energy Loss Function of Silicene and Germanene Multilayers on Silver

November 4, 2013
Author(s)
Anna L. Rast, Vinod K. Tewary
We calculate electron energy loss spectra (EELS) for composite plasmonic structures based on silicene and germanene. A continued-fraction expression for the effective dielectric function is used to perform multiscale calculations of EELS for both silicene

Airbrushed Nanofiber Scaffolds Support Bone Marrow Stromal Cell Differentiation

November 1, 2013
Author(s)
Carl G. Simon Jr., Wojtek J. Tutak, Sumona Sarkar, Tanya M. Farooque, Jyotsnendu J. Giri, Dongbo Wang, Sheng Lin-Gibson, Joachim Kohn, Durgadas Bolikal
Nanofiber scaffolds are effective for tissue engineering since they emulate the fibrous nanostructure of native extracellular matrix (ECM). Although electrospinning has been the most common approach for fabricating nanofiber scaffolds, airbrushing

Optical Coherence Tomography for Dimensional Metrology of Lab-on-a-chip devices

October 27, 2013
Author(s)
Darwin R. Reyes-Hernandez, Michael W. Halter, Jeeseong Hwang
Here we present a new metrology tool for the determination of the dimensions of channels from final product Lab-on-a-chip devices. Using Optical Coherence Tomography (OCT) areas of up to 12 mm x 12 mm can be imaged in less than 1 second, without the need

Analyzing a Co-Polymer Aramid Fiber for Use in Soft Body Armor

October 25, 2013
Author(s)
Walter G. McDonough, Jae Hyun Kim, Nathanael A. Heckert, Amanda L. Forster, Scott A. Wight, Joy P. Dunkers, Gale A. Holmes
Since the well-publicized failure of body armor used by a police officer, it has become imperative that the long-term properties and performance of new fibers being considered for use be understood. The range of interest is from the molecular properties of

Morphing Metal-Polymer Janus Particles

October 25, 2013
Author(s)
Lewis M. Cox, Jason Killgore, Zhengwei Li, Zheng Zhang, Donna C. Hurley, Jianliang Xiao, Yifu Ding
Shape memory polymers have the unique ability to memorize and recover their permanent shapes after being programmed to hold high strain levels up to a few hundred percent. While studies have traditionally focused on utilizing shape memory effects for macro

Measurement, Standards, and Data Needs for CO2 Capture Materials: A Critical Review

October 21, 2013
Author(s)
Laura Espinal, Dianne L. Poster, Winnie K. Wong-Ng, Andrew J. Allen, Martin L. Green
The commercial deployment of cost-effective carbon capture technology is hindered partially by the lack of a proper suite of materials-related standards, data, and measurement methods, which would provide critical information for the systematic design of
Displaying 676 - 700 of 1856