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Displaying 426 - 450 of 1926

Buckling Instabilities in Polymer Brush Surfaces via Postpolymerization Modification

October 30, 2017
Author(s)
Wei Guo, Cassandra M. Reese, Li Xiong, Phillip K. Logan, Brittany J. Thompson, Christopher Stafford, Anton Ievlev, Bradley S. Lokitz, Olga S. Ovchinnikova, Derek L. Patton
We report a simple route to engineer ultrathin polymer brush surfaces with wrinkled and creased morphologies using postpolymerization modification (PPM), where the length scale of the buckled features can be tuned using PPM reaction time and sequence. We

Knot Energy, Complexity, and Mobility of Knotted Polymers

October 17, 2017
Author(s)
Luis F. Vargas Lara, Ahmed M. Hassan, Marc A. Mansfield, Jack F. Douglas
The Newtonian capacity C of an object is defined by the equilibrium energy, EN =1/C, of a charge distribution on a conductive object and provides a classical measure of object shape. It is well known, for example, that C is minimized for a sphere for all

Wrinkling-to-delamination transition in thin polymer films on compliant substrates

October 9, 2017
Author(s)
Adam J. Nolte, Jun Y. Chung, Chelsea S. Davis, Christopher Stafford
Compressing a thin, stiff film attached to a thick, compliant substrate can lead to a number of different modes of mechanical deformation depending upon the material properties of the system. In this article we explore direct transitions from surface

Nanostructural Evidence of Mechanical Aging and Performance Loss in Ballistic Fibers

September 29, 2017
Author(s)
John Howarter, Ming Liu, Walter G. McDonough, Christopher Soles, Gale A. Holmes
It is understood that the ballistic resistance of aromatic polyamide fibers is related to the fiber's ultimate tensile strength, strain-to-failure, and Young's modulus. Ideal high-performance ballistic materials maximize these properties while minimizing

Simple Transfer from Spin Coating to Blade Coating Through Processing Aggregated Solutions

September 22, 2017
Author(s)
Jeff L. Hernandez, Nabankur Deb, Rylan M. Wolfe, Chi K. Lo, Sebastian Engmann, Lee J. Richter, John R. Reynolds
To develop an understanding of the effect spin coating or blade coating have on the morphology of polymer:fullerene thin films for organic solar cells, we have investigated the morphology of poly[5-(2-hexyldecyl)-1,3-thieno[3,4-c]pyrrole-4,6-dione-alt-5,5-

Enhanced durability of CNT based hierarchical composites subjected to accelerated aging environments.

September 21, 2017
Author(s)
Ajay Krishnamurthy, Donald L. Hunston, Amanda L. Forster, Bharath NMN Natarajan, Sunny Wicks, Paul E. Stutzman, James A. Liddle, Aaron M. Forster, Brian L. Wardle
As carbon nanotube (CNT) based composites are increasingly being identified as viable aerospace materials, it is vital to study their environmental degradation characteristics. In this work, the durability of CNT reinforced hierarchical alumina fiber

Polymer Informatics: Opportunities and Challenges

September 15, 2017
Author(s)
Debra J. Audus, Juan J. de Pablo
We are entering an era where large volumes of scientific data, coupled with algorithmic and computational advances, can reduce both the time and cost of developing new materials. This emerging field known as materials informatics has gained acceptance for

Strain Measurement of 3D Structured Nanodevices by EBSD

August 20, 2017
Author(s)
William A. Osborn, Lawrence H. Friedman, Mark D. Vaudin
We present a new methodology to accurately measure strain magnitudes from 3D nanodevices using Electron Backscatter Diffraction (EBSD). Because the dimensions of features on these devices are smaller than the interaction volume for backscattered electrons

Moisture Uptake Characterization in Nanocellulose Using Microwave Cavity

August 17, 2017
Author(s)
Caglar Emiroglu, Bharath N. Natarajan, Jeffrey W. Gilman, James Alexander Liddle, Jan Obrzut
Cellulose nanocrystal films with different helical modulation lengths are characterized. Films are obtained by tuning the rate of evaporation and surface functionalization. Dielectric constant measurements are performed and the water confinement is

Epitaxially-grown self-assembled Bi2Se3/Bi2MnSe4 multilayer heterostructures

August 14, 2017
Author(s)
Joseph A. Hagmann, Xiang Li, Si-Ning Dong, Sergei Rouvimov, Sujitra J. Pookpanratana, Kin Man Yu, Tatyana Orlova, Curt A. Richter, David G. Seiler, Xinyu Liu, Jacek K. Furdyna, Margaret Dobrowolska
Progress in understanding topologically non-trivial systems offers the promise of predicting novel systems that demonstrate the remarkable properties associated with topological systems, such as unidirectional spin-polarized surface current and the

Weld formation during material extrusion additive manufacturing

August 11, 2017
Author(s)
Jonathan E. Seppala, Seung Hoon Han, Kaitlyn E. Hillgartner, Chelsea S. Davis, Kalman D. Migler
Material extrusion (ME) is a layer-by-layer additive manufacturing process that is now used in personal and commercial production where prototyping and customization are required. However, parts produced from ME frequently exhibit poor mechanical

Energy renormalization approach to coarse-graining of polymer dynamics

August 8, 2017
Author(s)
Wenjie Xia, Jake Song, Cheol Jeong, David D. Hsu, Frederick R. Phelan Jr., Jack F. Douglas, Sinan Keten
A major challenge in soft matter science is the bottom-up prediction of the temperature- dependent behavior of amorphous glass-forming (GF) polymers. Coarse-grained (CG) models derived from atomistic simulation data offer chemical specificity and access to

Influence of polymer architecture on diffusion in polymers melts

August 2, 2017
Author(s)
Alexandros Chremos, Cheol Jeong, Jack F. Douglas
Recent simulations have indicated that the thermodynamic properties and the glassy dynamics of polymer melts are strongly influenced by average molecular shape, as quantified by the radius of gyration tensor of the polymer molecules, and that average

Measurement and Modeling of the Ability of Crack Fillers to Prevent Chloride Ingress into Mortar

August 1, 2017
Author(s)
Scott Z. Jones, Dale P. Bentz, Jeffrey Davis, Daniel S. Hussey, David L. Jacobson, John L. Molloy, John R. Sieber
One of the most common repair procedures applied to damaged concrete is the filling of cracks by the application (injection) of an organic polymer. This operation is performed to increase the service life of the concrete by removing a preferential pathway

Fast-Responding Bio-Based Shape Memory Thermoplastic Polyurethanes

July 14, 2017
Author(s)
Zoran S. Petrovic, Jelena Milic, Fan Zhang, Jan Ilavsky
Fast response shape-memory polyurethanes were prepared from bio-based polyols, diphenyl methane diisocyanate and butane diol. The bio-based polyester polyols were synthesized from 9-hydroxynonanoic acid, a product obtained by ozonolysis of fatty acids
Displaying 426 - 450 of 1926
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