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 by: Andrew J Allen (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 126 - 150 of 257

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 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

Development of Ultrasmall-Angle X-ray Scattering - X-ray Photon Correlation Spectroscopy

February 1, 2011
Author(s)
Fan Zhang, Andrew J. Allen, Lyle E. Levine, Jan Ilavsky, Gabrielle G. Long, Anthony M. Santana
In this paper, we present the development of ultrasmall-angle X-ray scattering - X-ray photon correlation spectroscopy (USAXS-XPCS). This technique takes advantage of Bonse-Hart crystal optics and is capable of probing the slow equilibrium and
Was this page helpful?