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Search Publications by: Jeffrey Fagan (Fed)

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Displaying 76 - 97 of 97

Sample Preparation Protocols for Realization of Reproducible Characterization of Single-walled Carbon Nanotubes

December 1, 2009
Author(s)
Angela R. Hight Walker, Jeffrey A. Fagan, Stephanie A. Hooker, Michael T. Postek, Stephen A. Wise, Andras Vladar, Rolf L. Zeisler
Harmonized sample pre-treatment is an integral first step in ensuring metrological quality of measurements as regards repeatability, inter-laboratory reproducibility and commutability. The development of standard preparation methods for SWCNT samples is

Microscale Polymer-Nanotube Composites

July 2, 2009
Author(s)
Erik K. Hobbie, Jeffrey A. Fagan, Jan Obrzut, Steven D. Hudson
Microscopic polymer colloids with an interfacial coating of purified single-wall carbon nanotubes (SWCNTs) have been synthesized from length and type sorted SWCNTs. Aqueous SWNCT suspensions sorted through density-gradient ultracentrifugation are used to

Carbon Nanomaterials Standards Efforts at NIST

May 24, 2009
Author(s)
Jeffrey A. Fagan
Development of carbon nano-materials for applications has been hindered to date by a lack of standard protocols, i.e. documentary standards, and physical standards such as reference materials, which enable the common inter-comparison between laboratories

2nd Annual Tri-National Workshop on Standards for Nanotechnology - (NIST presentations)

December 10, 2008
Author(s)
Ronald G. Dixson, Jon R. Pratt, Vincent A. Hackley, James E. Potzick, Richard A. Allen, Ndubuisi G. Orji, Michael T. Postek, Herbert S. Bennett, Theodore V. Vorburger, Jeffrey A. Fagan, Robert L. Watters
A new era of cooperation between North American National Measurement Institutes (NMIs) was ushered by the National Research Council of Canada Institute for National Measurement Standards (NRC-INMS) on February 7, 2007 when the first Tri-National workshop

Chromatographic Separation of Single Wall Carbon Nanotubes

October 16, 2008
Author(s)
Barry J. Bauer, Vardhan Bajpai, Jeffrey Fagan, Matthew Becker, Erik K. Hobbie
Size exclusion chromatography (SEC) has been used to separate single wall carbon nanotubes (SWNT) dispersed by chemical modification in organic solvents and by DNA in aqueous solution. The chromatographic detection includes size sensitive detectors, multi

Centrifugal Length Separation of Carbon Nanotubes

October 1, 2008
Author(s)
Jeffrey A. Fagan, Matthew Becker, Jae H. Chun, Barry J. Bauer, Jeffrey R. Simpson, Angela R. Hight Walker, Erik K. Hobbie
Separation of single wall carbon nanotubes (SWCNTs) by length via centrifugation in a high density medium, and the characterization of both the separated fractions and the centrifugation process are presented. Significant quantities of the separated SWCNTs

Size Separation of Single Wall Carbon Nanotubes by Flow-Field Flow Fractionation

April 1, 2008
Author(s)
Jae H. Chun, Jeffrey A. Fagan, Erik K. Hobbie, Barry J. Bauer
Flow-field flow fractionation (Flow-FFF) is used to separate single wall carbon nanotubes (SWNTs) dispersed in aqueous medium by the use of DNA. On-line measurements are made of SWNT concentration, molar mass, and size by using UV-Vis absorption and multi

Relationship between dispersion metric and properties of PMMA/SWNT nanocomposites

June 13, 2007
Author(s)
Takashi Kashiwagi, Jeffrey Fagan, Jack F. Douglas, Kazuya Yamamoto, N. Alan Heckert, Stefan D. Leigh, Jan Obrzut, Fangming Du, Minfang Mu, Sheng Lin-Gibson, K Winey, R Haggenmueller
Particle spatial dispersion is a crucial characteristic of polymer composite materials and this property is recognized as especially important innanocomposite materials due to the general tendency of nanoparticles to aggregate under processing conditions

Measurement of Single Wall Nanotube Dispersion by Size Exclusion Chromatography

May 9, 2007
Author(s)
Barry J. Bauer, Matthew Becker, Vardhan Bajpai, Jeffrey A. Fagan, Erik K. Hobbie, Kalman D. Migler, Charles M. Guttman, William R. Blair
The dispersion of nanotubes in solution is necessary in order to achieve the goal of sorting and manipulating nanotubes by length and type and to then prepare high quality monodisperse samples. A necessary step is the proper characterization of the

Length Fractionation of Carbon Nanotube Using Centrifugation

February 28, 2007
Author(s)
Jeffrey A. Fagan, Matthew Becker, Jae H. Chun, Erik K. Hobbie
A recent article by Arnold et al. (Nature Nanotech., 1, 60-65, 2006)1 demonstrated the use of ultracentrifugation on single wall carbon nanotubes (SWNTs) within a density gradient to produce chirality separation of the nanotubes. The authors of this letter

Length Dependent Uptake of DNA-Wrapped Single Walled Carbon Nanotubes

January 1, 2007
Author(s)
Matthew Becker, Jeffrey Fagan, Nathan D. Gallant, Barry J. Bauer, Vardhan Bajpai, Erik K. Hobbie, Silvia H. De Paoli Lacerda, Kalman D. Migler, J P. Jakupciak
DNA-wrapped single wall carbon nanotubes (SWNTs) with broad length distributions are shown to reduce the viability of IMR90 primary human lung fibroblast cells above the (23 to 25) ug/mL concentration regime. Furthermore using well-defined length fractions

Optical Anisotropy of Semiconducting Single-Wall Carbon Nanotubes

January 1, 2007
Author(s)
Jeffrey Fagan, Erik K. Hobbie, Jeffrey R. Simpson, Lee J. Richter, Idan Mandelbaum, Vardhan Bajpai, Derek L. Ho, Barry J. Bauer, Angela HightWalker, Ryan Raffaelle
We measure the full optical anisotropy of individual semiconducting single-wall carbon nanotubes (SWNTs). Dispersion of aligned SWNTs in stretched polymer films is confirmed with small-angle scattering and near-infrared fluorescence spectroscopy. By

Comparative Measures of Single Wall Carbon Nanotube Dispersion

September 14, 2006
Author(s)
Jeffrey A. Fagan, Brian Landi, Idan Mandelbaum, Vardhan Bajpai, Barry J. Bauer, Kalman D. Migler, Jeffrey R. Simpson, Angela R. Hight Walker, Ryan Raffaelle, Erik K. Hobbie
Model polymer composites of DNA wrapped single-wall carbon nanotubes (SWNTs) dispersed in polyacrylic acid are used for a systematic comparison of the different metrologies currently used to evaluate SWNT dispersion. Application of a pH-controlled

Quantitative, Interactive Measurement of Tissue Engineering Scaffold Structure Using Immersive Visualization

January 1, 2006
Author(s)
Jeffrey Fagan, Erik K. Hobbie, Brian Landi, Idan Mandelbaum, Vardhan Bajpai, Barry J. Bauer, Kalman D. Migler, Jeffrey R. Simpson, Angela R. Hight Walker, Ryan Raffaelle
At NIST, we are using new approaches to better understand and quantify the structure of tissue engineering scaffolds. This approach uses immersive visualization (IV) and is inherently three dimensional, multivariate and interactive, providing real-time