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Search Publications by: Ryan Nieuwendaal (Fed)

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Displaying 26 - 43 of 43

Classification of Semiconducting Polymeric Mesophases to Optimize Device Post-Processing

August 17, 2015
Author(s)
Chad R. Snyder, Regis J. Kline, Dean M. DeLongchamp, Ryan C. Nieuwendaal, Lee J. Richter, Martin Heeney, Iain McCulloch
Semiconducting polymers form a variety of phases and mesophases that respond differently to post-deposition solvent or thermal treatments. Here it is shown that classification of these materials into their appropriate mesophases can be a useful tool to

Quantifying Crystallinity in High Molar Mass Poly(3-hexylthiophene)

June 3, 2014
Author(s)
Chad R. Snyder, Ryan C. Nieuwendaal, Dean M. DeLongchamp, Christine K. Luscombe, Prakash Sista, Shane D. Boyd
We extend a recent comprehensive study of 3-hexylthiophene oligomers to high molar mass poly(3-hexylthiophene) (P3HT) fractions, such as those used in organic photovoltaic devices. Through a combination of differential scanning calorimetry (DSC) and 13C

Comparison of the Properties of Cellulose Nanocrystals and Cellulose Nanofibrils Isolated From Bacteria, Tunicate, and Wood Processed Using Acid, Enzymatic, Mechanical, and Oxidative Methods

April 18, 2014
Author(s)
Iulia A. Sacui, Jeffrey W. Gilman, Ryan C. Nieuwendaal, Stephan J. Stranick, Henryk Szmacinski, Mehdi Jorfi, Christopher Weder, Johan Foster, Richard Olsson, Daniel Burnett
This work describes the study and characterization of native cellulose nanocrystals and nanofibrils (CNCs, CNFs), whose crystallinity, morphology, aspect ratio, and surface chemistry depend on the raw material source and hydrolysis conditions. Measurement

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

Formation of Extended Ionomeric Network by Bulk Polymerization of L,D-lactide with Layered Double Hydroxide

November 22, 2012
Author(s)
Edward D. McCarthy, Mauro Zammarano, Douglas M. Fox, Ryan Nieuwendaal, Yeon S. Kim, P H. Maupin, Paul C. Trulove, Jeffrey W. Gilman
We report the formation of an ionomeric network in a poly(L,D-lactide) hybrid nanocomposite, (PLDLA-HYB) during in-situ melt polymerization of L,D lactide in the presence of magnesium/aluminium layered-double-hydroxide (LDH) without added catalyst. The

Measuring domain sizes and compositional heterogeneities in P3HT-PCBM bulk heterojunction thin films with 1H spin diffusion NMR spectroscopy

March 21, 2012
Author(s)
Ryan C. Nieuwendaal, Hyun Wook Ro, David Germack, Regis J. Kline, Calvin Chan, Amit K. Agrawal, David J. Gundlach, David L. VanderHart, Dean M. DeLongchamp
In this manuscript we show that 1H spin diffusion NMR is a valuable method for estimating the domain sizes in thin films of a polymer-fullerene blend for bulk heterojunction (BHJ) photovoltaics. Variations in common BHJ film processing parameters have

Polymer Dynamics in Constrained Geometries

February 1, 2012
Author(s)
Christopher Soles, Ryan Nieuwendaal, Huagen H. Peng
The wide-spread interest in the dynamical property of organic materials under strong states of confinement largely began with differential scanning calorimeter (DSC) measurements in the early 90's of the glass transition and heat capacity of glass forming