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Search Publications by: Andrew J Allen (Fed)

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Displaying 51 - 75 of 129

Reference Diffraction Patterns, Microstructure, and Pore Size Distribution for the Copper (II) benzene-1,3,5-tricarboxylate Metal Organic Framework (Cu-BTC) Compounds

March 1, 2015
Author(s)
Winnie K. Wong-Ng, James A. Kaduk, Daniel W. Siderius, Andrew J. Allen, Laura Espinal, Brad Boyerinas, Igor Levin, Matthew Suchomel, Jan Ilavsky, Eric J. Cockayne, Hui Wu
Cu-paddle-wheel-based Cu3(BTC)2 (nicknamed Cu-BTC, where BTC ≡ benzene 1,3,5-tricarboxylate) is a metal organic framework (MOF) compound that adopts a zeolite topology. We have determined the pore size distribution using the Gelb and Gubbins technique, the

Beyond the International Year of Crystallography

February 1, 2015
Author(s)
Andrew J. Allen, Janos Hajdu, Anke R. Kaysser-Pyzalla
It is now one year since all International Union of Crystallography (IUCr) journals became online only, and this is just one of the developments during the International Year of Crystallography, IYCr 2014. Perhaps, most conspicuously, IUCr’s new flagship

Structural and Dynamical Studies of Acid Mediated Conversion in Amorphous-Calcium-Phosphate Based Dental Composites

October 31, 2014
Author(s)
Fan Zhang, Andrew J. Allen, Lyle E. Levine, Mark D. Vaudin, Drago Skrtic, Joseph M. Antonucci, Kathleen M. Hoffman, Anthony A. Giuseppetti, Jan Ilavsky
Amorphous calcium phosphate (ACP) based composites are promising restorative dental materials attributable to ACP's capacity to release calcium and phosphate ions through a complex reaction in which ACP is converted to its crystalline, apatitic form

Use of Single Particle Inductively Coupled Plasma Mass Spectrometry to Characterize a New Silver Nanoparticle Reference Material

June 11, 2014
Author(s)
Karen E. Murphy, Jingyu Liu, William F. Guthrie, Justin M. Gorham, John E. Bonevich, Andrew J. Allen, Michael R. Winchester, Vincent A. Hackley, Robert MacCuspie
In this study we use inductively coupled plasma mass spectrometry operated in single particle mode (spICP-MS) to simultaneously characterize the size distribution and dissolved silver fraction of a new silver nanoparticle (AgNP) candidate reference

Evolution of electrochemical interfaces in solid oxide fuel cells (SOFC): a Ni and Zr resonant anomalous ultra-small-angle X-ray scattering studywith elemental and spatial resolution across the cell assembly

June 1, 2014
Author(s)
Andrew J. Allen, Jan Ilavsky, Pete R. Jemian, Artur Braun
Electrochemical interfaces are key to the direct conversion of fuels to electrical energy and lend energy converters like solid oxide fuel cells (SOFC) their functionality. Over extended operation at high temperatures, the microstructure of the underlying

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

Just Add Water – reproducible singly dispersed silver nanoparticle suspensions

June 19, 2013
Author(s)
Robert I. MacCuspie, Andrew J. Allen, Matthew N. Martin, Vincent A. Hackley
Silver nanoparticles (AgNPs) are of interest due to their antimicrobial attributes, which are derived from their inherent instability and subsequent release of silver ions into solution. At the same time, this instability makes achieving stable long-term

Flexible Metal Organic Framework Compound, Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4]n, for CO2 Sorption Applications

April 7, 2013
Author(s)
Winnie K. Wong-Ng, Jeffrey T. Culp, Yu-Sheng Chen, Laura Espinal, Andrew J. Allen, Daniel W. Siderius, Craig M. Brown, Wendy Queen, Peter Zavalij, Christopher Matranga
New sorbent materials are required for carbon capture because coal-fired electrical power plants, the largest emitters of this greenhouse gas, will continue to produce much of our nation’s electricity for at least several decades. Within the family of

Improved Synthesis and Crystal Structure of the Flexible Pillared Layer Porous Coordination Polymer: Ni(1,2-bis(4-pyridyl)ethylene)[Ni(CN)4]

April 4, 2013
Author(s)
Winnie K. Wong-Ng, Jeffrey T. Culp, Yu-Sheng Chen, Peter Zavalij, Laura Espinal, Daniel W. Siderius, Andrew J. Allen, Steve Scheins, Christopher Matranga
A new method of synthesis was developed for the flexible coordination polymer Ni(L)[Ni(CN)4], L=1,2-bis(4-pyridyl)ethylene (bpene) to increase its CO2 sorption uptake. The structure of the newly synthesized bpene has been determined by synchrotron X-ray

Structure and Dynamics Studies of Concentrated Micrometer-Sized Colloidal Suspensions

January 7, 2013
Author(s)
Fan Zhang, Andrew J. Allen, Lyle E. Levine, Jan Ilavsky, Gabrielle G. Long
We present an experimental study of the structural and dynamical properties of concentrated suspensions of a series of different sized polystyrene microspheres dispersed in glycerol for volume fraction concentrations between 10 % and 20 %. The static

High-energy Ultra-Small Angle X-ray Scattering Instrument at the Advanced Photon Source

December 1, 2012
Author(s)
Andrew J. Allen, Lyle E. Levine, Fan Zhang, Gabrielle G. Long, Jan Ilavsky, Pete R. Jemian
This paper reports recent tests performed on the Bonse-Hart-type ultra-small angle X-ray scattering (USAXS) instrument at the Advanced Photon Source with higher-order reflection optics — Si (440) instead of Si (220) — and with X-ray energies greater than

Ultra-Small-Angle X-ray Scattering-X-ray Photon Correlation Spectroscopy: A New Measurement Technique for in-situ Studies of Equilibrium and Nonequilibrium Dynamics

May 1, 2012
Author(s)
Fan Zhang, Andrew J. Allen, Lyle E. Levine, Jan Ilavsky, Gabrielle G. Long
Ultra-small-angle X-ray scattering—X-ray photon correlation spectroscopy (USAXS-XPCS) is a novel measurement technique for the study of equilibrium and slow nonequilibrium dynamics in disordered materials. This technique fills an existing gap between the

Time dependent CO2 sorption hysteresis in a one-dimensional microporous octahedral molecular sieve

April 6, 2012
Author(s)
Laura Espinal, Winnie K. Wong-Ng, Andrew J. Allen, Daniel W. Siderius, Chad R. Snyder, Eric J. Cockayne, Lan (. Li, James A. Kaduk, Anais E. Espinal, Steven L. Suib, Chun Chiu
A critical challenge in the development of novel carbon capture materials with engineered porous architectures is to understand and control the phenomenon of sorption hysteresis, whereby the path to adsorption of gas molecules by the porous host differs

Ultra-small-Angle X-ray Scattering - X-ray Photon-Correlation Spectroscopy Studies of Incipient Structural Changes in Amorphous Calcium Phosphate Based Dental Composites

February 28, 2012
Author(s)
Fan Zhang, Andrew J. Allen, Lyle E. Levine, Laura Espinal, Joseph M. Antonucci, Drago Skrtic, Justin N. O'Donnell, Jan Ilavsky
The local structural changes in amorphous calcium phosphate (ACP) based dental composites were studied upon heating using both static, bulk measurement techniques and recently developed ultra-small angle X-ray scattering - X-ray photon correlation

Selective Adsorption of CO2 from Light Gas Mixtures Using a Structurally Dynamic Porous Coordination Polymer

April 29, 2011
Author(s)
Winnie K. Wong-Ng, Andrew J. Allen, Laura Espinal, Kristi L. Kauffman, Jeffrey T. Culp, Angela Goodman, Thomas G. Brown, Mark P. Bernardo, Russel J. Pancoast, Danielle Chirdon, Christopher Matranga
The selective adsorption of CO2 from binary mixtures of N2 and CH4 was investigated using a structurally dynamic porous coordination polymer, catena-bis(dibenzoylmethanato)-(4,4’bipyridyl)nickel (II), ‘NiDBM-Bpy’, as the separation sorbent. A third gas

Challenges for Physical Characterization of Silver Nanoparticles Under Pristine and Environmentally Relevant Conditions

March 17, 2011
Author(s)
Robert I. MacCuspie, Kim Rogers, Manomita Patra, Zhiyong Suo, Andrew J. Allen, Matthew N. Martin, Vincent A. Hackley
The conditions used to disperse silver nanoparticles (AgNPs) strongly impact their resulting size measurements and agglomeration state, based on the underlying metrology and physical chemistry, respectively. A series of AgNP materials with reported