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Search Publications by: Jeffrey Fagan (Fed)

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Displaying 26 - 50 of 96

In-situ near-field probe microscopy of plasma processing

December 27, 2018
Author(s)
Alexander Tselev, Jeffrey Fagan, Andrei Kolmakov
There exists a great necessity for in situ nanoscale characterization of surfaces and thin films during plasma treatments. To address this need, the current approaches rely on either ‘post mortem' sample microscopy, or in situ optical methods. The latter

Nanoparticle Manufacturing - Heterogeneity through Processes to Products

August 15, 2018
Author(s)
Samuel M. Stavis, Jeffrey Fagan, Michael Stopa, James Alexander Liddle
Commercial products are now making use of the unique properties of nanoscale particles. However, common challenges of making nanoparticles into products still limit their impact. In this article, we review recent advances in nanoparticle manufacturing in

A radial calibration window for analytical ultracentrifugation

July 20, 2018
Author(s)
Thomas W. LeBrun, Peter Schuck, Wei Ren, Justine Yoon, Xianghui Dong, Nicole Y. Morgan, Jeffrey Fagan, Huaying Zhao
Analytical ultracentrifugation (AUC) is a first-principles based method for studying particles in solution by monitoring the evolution of their radial concentration distribution as a function of time in the presence of a high centrifugal field. In

Alkane Encapsulation Induces Strain in Small Diameter Single-Wall Carbon Nanotubes

May 4, 2018
Author(s)
Jason K. Streit, Jochen I. Campo, Chad R. Snyder, Ming Zheng, Jeffrey R. Simpson, Angela R. Hight Walker, Jeffrey Fagan
Encapsulation of linear alkane molecules in the endohedral volumes of small diameter single- wall carbon nanotubes (SWCNTs) is shown to induce diameter dependent strain on the hexagonal lattice of carbon atoms composing the tubular structure. For the

A Low Energy Route to DNA-wrapped Carbon Nanotubes via Replacement of Bile Salts

August 31, 2017
Author(s)
Ming Zheng, Jason K. Streit, Jeffrey A. Fagan
DNA-wrapped carbon nanotubes are a class of bio-nano hybrid molecules that exhibit extended bonding structures and have enabled carbon nanotube sorting, controlled assembly, and biosensing and bioimaging applications. The current method of synthesizing

Progress towards total structure control in SWCNT populations

May 14, 2017
Author(s)
Jeffrey A. Fagan
As-synthesized single-wall carbon nanotube (SWCNT) populations contain substantial distributions of SWCNT structures, including in the distribution of species ((n,m) chiralities) and enantiomers (i.e. the handedness of the lattice vector), as well as in

A Comparison of Quality of Dispersion of Single Wall Carbon Nanotubes Using Different Surfactants and Biomolecules

February 19, 2017
Author(s)
Jeffrey W. Gilman, R Haggenmueller, Sameer Rahatekar, Jeffrey Fagan, Jae H. Chun, Matthew Becker, Rajesh R. Naik, Todd Krauss, Lisa Carlson, Shana O. Kelley, Paul C. Trulove, D M. Fox, John Kadla
The application of single wall carbon nanotubes (SWCNT) in current and future applications crucially depends on the ability to process SWCNT in a solvent to yield high quality dispersions characterized by individual SWCNTs and possessing a minimum of SWCNT

Relationship Between Quantitative Dispersion and Physical Properties of PMMA/SWNT Nanocomposites

February 19, 2017
Author(s)
Takashi Kashiwagi, Jeffrey Fagan, Keith Yamamoto, A N. Heckert, Stefan D. Leigh, Jan Obrzut, F Du, Sheng Lin-Gibson, Minfang Mu, K Winey, R Haggenmueller, Jack F. Douglas
Six PMMA/SWNT(0.5 wt%) nanocomposite samples intended to have different dispersion levels were prepared by the coagulation method using six different concentrations of SWNTs in DMF from 0.05 mg/ml to 1.2 mg/ml. The morphology of the samples was determined

Separation of Double-Wall Carbon Nanotubes by Electronic Type and Diameter

January 24, 2017
Author(s)
Jason K. Streit, Stephanie Lam, Yanmei Piao, Angela R. Hight Walker, Jeffrey A. Fagan, Ming Zheng
In this work, we introduce a new procedure for the efficient isolation and subsequent separation of double-wall carbon nanotubes (DWCNTs). A simplified rate zonal ultracentrifugation (RZU) process is first applied to obtain samples of highly enriched

Differentiating Left- and Right-Handed Carbon Nanotubes by DNA

December 28, 2016
Author(s)
Ming Zheng, Geyou Ao, Jason K. Streit, Jeffrey A. Fagan
The emergence of macromolecules of defined structures is a crucial step in the evolution of life. The mechanism by which these structures are selected from astronomical numbers of biopolymer sequences has long been a topic of controversy1,2. Experimenting

Enhancing Single-Wall Carbon Nanotube Properties Through Controlled Endohedral Filling

May 10, 2016
Author(s)
Jochen I. Campo, Yanmei Piao, Stephanie Lam, Christopher Stafford, Jason K. Streit, Jeffrey R. Simpson, Angela R. Hight Walker, Jeffrey Fagan
Chemical control of the endohedral volume of single-wall carbon nanotubes (SWCNTs) via liquid-phase filling is demonstrated to be a facile strategy to controllably modify properties of the nanotubes in manners significant for processing and proposed

Quantification of carbon nanotubes in environmental matrices: Current capabilities, case studies, and future improvements

April 6, 2016
Author(s)
Elijah J. Petersen, D. X. Flores-Cervantes, Thomas Bucheli, Lindsay C. Elliott, Jeffrey A. Fagan, Alexander Gogos, Shannon Hanna, Antonio R. Montoro Bustos, Desiree L. Plata, Vytautas Reipa, Paul Westerhoff, Michael R. Winchester, Elisabeth Mansfield
Carbon nanotubes (CNTs) have numerous exciting potential applications approaching commercialization. As such, quantitative measurements of CNTs in key environmental matrices (water, soil, sediment, and biological tissues) are needed to address concerns

The Nature of Record Efficiency Fluid-Processed Nanotube-Silicon Heterojunctions

April 20, 2015
Author(s)
Jeffrey A. Fagan, Erik K. Hobbie, John M. Harris, Matthew R. Semler
The dark transport characteristics of heterojunctions assembled from type, chirality and length-purified single-wall carbon nanotubes (SWCNTs) are used to clarify the nature of nanotube-silicon diodes and solar cells. The freestanding films show remarkable

How Large Can We Go? Isolation of > 1 nm Diameter Single-Wall Carbon Nanotubes Species using Aqueous Two Phase Extraction

April 14, 2015
Author(s)
Jeffrey A. Fagan, Erik Haroz, Rachelle Ihly, Hui Gui, Jeffrey Blackburn, Jeffrey R. Simpson, Stephen K. Doorn, Stephanie Lam, Angela R. Hight Walker, Ming Zheng
We demonstrate the effective separation of near-monochiral single-wall carbon nanotube (SWCNT) species with diameters > 1 nm through multi-stage aqueous two phase extraction (ATPE), and report an empirical function for the surfactant concentrations at

Redox sorting of carbon nanotubes

March 17, 2015
Author(s)
Hui Gui, Jason K. Streit, Jeffrey Fagan, Angela R. Hight Walker, Chongwu Zhou, Ming Zheng
This work expands the redox chemistry of single-wall carbon nanotube (SWCNT) by investigating its role in a number of SWCNT sorting processes. Using a polyethylene glycol (PEG)/dextran (DX) aqueous two-phase system, we show that electron-transfer reaction

Analytical Ultracentrifugation of Carbon Nanotubes

November 26, 2014
Author(s)
Jeffrey A. Fagan
Sedimentation velocity (SV) experiments on dispersed nanoparticles are a powerful method for determining otherwise hard to evaluate properties of the nanoparticle such as the density and size of the adsorbed interfacial layer, or for a direct evaluation of

Hydrodynamic Behavior of Carbon Nanotubes and Characterization of Length Distributions

February 28, 2014
Author(s)
Carlos A. Silvera Batista, Ming Zheng, Constantine Y. Khripin, Xiaomin X. Tu, Jeffrey Fagan
The sedimentation behavior of SWCNTs was studied through analytical ultracentrifugation. SWCNTs were dispersed with the aid of surfactants, doubly sorted by density and length to produce samples with invariant diameter distributions and aspect ratios that

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

On the Determination of Carbon by PGAA

November 10, 2013
Author(s)
Rolf L. Zeisler, Rick L. Paul, Jeffrey A. Fagan, Zsolt R?vay, Stefan S?llradl
Determination of carbon was achieved with reduction of background in prompt gamma activation analysis.

Elasticity and rigidity percolation in networks of type-purified single-wall carbon nanotubes on flexible substrates

October 29, 2013
Author(s)
John M. Harris, JiYeon Huh, Matthew R. Semler, Christopher Stafford, Steven Hudson, Jeffrey Fagan, Erik K. Hobbie
Wrinkles and folds in compressed thin films of type-purified single-wall carbon nanotubes (SWCNTs) on polydimethylsiloxane (PDMS) substrates are used to study the mechanical response of pristine nanotube networks. While the low-strain plateau moduli are