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Displaying 226 - 250 of 1944

Calibration Procedures for Orthogonal Superposition Rheology

November 18, 2020
Author(s)
Ran Tao, Aaron M. Forster
Orthogonal superposition (OSP) rheology is an advanced rheological technique that involves superimposing a small-amplitude oscillatory shear deformation orthogonal to a primary shear flow. This technique allows the measurement of structural dynamics of

EFFECTS OF PRE-STRAIN ON THE NON-LINEAR VISCOELASTIC PROPERTIES OF A MODEL SEALANT

November 18, 2020
Author(s)
Christopher C. White, Donald L. Hunston, Kar tean Tan
The non-linear viscoelastic properties of a model sealant were measured using stress relaxation tests conducted at different strain levels, x. Some specimens were measured with no previous strain history while others were given a preconditioning that

Estimating the Impact of 16 CFR Part 1633 on Bed Fire Outcomes

November 18, 2020
Author(s)
Stanley W. Gilbert, David Butry, Rick D. Davis, Richard Gann
Effective July 1, 2007, the U.S. Consumer Product Safety Commission promulgated a standard to severely reduce the heat release rate and the early heat output from mattresses and foundations when ignited by a flaming ignition source. This study estimates

AMB2018-03: Benchmark Physical Property Measurements for Material Extrusion Additive Manufacturing of Polycarbonate

October 29, 2020
Author(s)
Daniel P. Cole, Frank Gardea, Todd C. Henry, Jonathan Seppala, Edward Garboczi, Kalman D. Migler, Christopher M. Shumeyko, Jeffery R. Westrich, Sara Orski, Jeffery L. Gair
Material extrusion (MatEx) is finding increasing applications in additive manufacturing of thermoplastics due to the ease of use and the ability to process disparate polymers. Since part strength is anisotropic and frequently deviates negatively with

Correlation of Nano-morphology with Structural and Spectroscopic Studies in Organic Solar Cells

October 27, 2020
Author(s)
Eliot Gann, Christopher McNeill, Wenchao Huang, Dinesh Kabra, Urvashi Bothra, Nakul Jain, Amelia C. Liu
The nano-morphology of bulk heterojunction blends based on poly[[4,8-bis[(2- ethylhexyl)oxy]benzo[1,2-b:4,5- b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)carbonyl]thieno[3,4-b]thiophenediyl]] (PTB7) blended with [6,6]- phenyl-C71-butyric acid methyl

Percolation implications in the rheology of crystallization

October 26, 2020
Author(s)
Anthony P. Kotula, Kalman D. Migler
The rheology of polymer crystallization is an old problem that often defies explanation due to the complex interrelationships between crystallization and flow properties. Although separate measurements of rheology and crystallinity can give some

Rheology of Crystallizing LLDPE

October 8, 2020
Author(s)
Marat Andreev, David Nicholson, Anthony Kotula, Jonathan D. Moore, Jaap Den Doelder, Gregory C. Rutledge
Polymer crystallization occurs in many plastic manufacturing processes, from injection molding to film blowing. Linear low-density polyethylene (LLDPE) is one of the most commonly processed polymers, wherein the type and extent of short chain branching

Effects of Environmental Temperature and Humidity on the Geometry and Strength of Polycarbonate Specimens Prepared by Fused Filament Fabrication

October 3, 2020
Author(s)
Lichen Fang, Yan Yishu, Ojaswi Agarwal, shengyu Yao, Jonathan Seppala, Sung Hoon Kang
It is widely known that the printing quality of fused filament fabrication (FFF) is heavily affected by environmental temperature and humidity, as the case of warping and porosity. However, there is little understanding about the quantitative relations

Characterization of 3-Dimensional Printing and Casting Materials for use in Computed Tomography and X-ray Imaging Phantoms

September 15, 2020
Author(s)
Bryan E. Yunker, Andrew Holmgren, Karl Stupic, J. L. Wagner, S Huddle, R Shandas, R. F. Weir, Katy Keenan, Edward Garboczi, Stephen E. Russek
Imaging phantoms are used to calibrate and validate the performance of medical computed tomography (CT) systems. Many new materials developed for three-dimensional (3D) printing processes may be useful in the direct printing or casting of biomimetic and

Electron and x-ray focused beam-induced cross-linking in liquids: Toward rapid continuous 3D nanoprinting and interfacing using soft materials

September 15, 2020
Author(s)
Tanya Gupta, Evgheni Strelcov, Glenn Holland, Joshua D. Schumacher, Yang Yang, Mandy Esch, Vladimir Aksyuk, Patrick Zeller, Matteo Amati, Luca Gregoratti, Andrei Kolmakov
Additive fabrication of biocompatible 3D structures out of liquid hydrogel solutions has become pivotal technology for tissue engineering, soft robotics, biosensing, drug delivery etc. Electron and X-ray lithography are well suited to pattern nanoscopic

Stress and Strain Heuristics for a Layered Elastomeric Foam at Medium Impact Rates

September 14, 2020
Author(s)
Alexander Landauer, Jared C. Van Blitterswyk, Michael Riley, Aaron Forster
Impact mitigating materials (IMMs) are used to reduce injury or damage due to a blunt impact, which often occurs at high rates or energies. Innovation in IMMs and designs strategies are required for the development of safer protective equipment. A key

Method development in interaction polymer chromatography

September 1, 2020
Author(s)
Andre M. Striegel
Interaction polymer chromatography (IPC) is an umbrella term covering a large variety of primarily enthalpically-dominated macromolecular separation methods. These include temperature- gradient interaction chromatography, interactive gradient polymer

Thickness-Dependent Permeability of Molecular Layer-By-Layer Polyamide Membranes

August 28, 2020
Author(s)
William D. Mulhearn, Vladimir Oleshko, Christopher Stafford
We present the thickness-dependent permeability of highly crosslinked polyamide (PA) membranes formed by a molecular layer-by-layer (mLbL) deposition process. The deposition allows for the synthesis of extremely smooth, uniform PA films of tunable

X-ray Scattering Studies of Reverse Osmosis Materials

August 25, 2020
Author(s)
Qinyi Fu, Nisha Verma, Benjamin S. Hsiao, Francisco J. Medellin-Rodriguez, Peter Beaucage, Christopher Stafford, Benjamin M. Ocko
Scarcity of freshwater is becoming a world crisis. In a recent annual risk report, the World Economic Forum lists it in their greatest global risk category. Currently, about four billion people live under conditions of severe water scarcity for at least

Linking Theory to Practice: Predicting Ballistic Performance from Mechanical Properties of Aged Body Armor

August 24, 2020
Author(s)
Amanda L. Forster, Dennis D. Leber, Amy E. Engelbrecht-Wiggans, Virginie A. Landais, Allen Chang, Emilien J. Guigues, Guillaume Messin, Michael A. Riley
It has long been a goal of the body armor testing community to establish an individualized, scientific-based protocol for predicting end-of-life of fielded body armor ballistic performance. A major obstacle in achieving this goal is that the test methods

The Impact and Fate of Graphene Oxide in Graphene Oxide/Polymer Nanocomposites Exposed to Ultraviolet Irradiation

August 11, 2020
Author(s)
David G. Goodwin, Trinny Lai, Yadong Lyu, Chen Yuan Lu, Alejandro Campos, Vytautas Reipa, Tinh Nguyen, Li Piin Sung
Ultraviolet (UV) radiation, heat and moisture can lead to polymer degradation outdoors but the effect of graphene oxide (GO) nanofiller incorporation on this process is unknown. Since GO can improve the mechanical, barrier, and thermal properties of a

The Concentration Dependence of the Size and Symmetry of a Bottlebrush Polymer in a Good Solvent

August 7, 2020
Author(s)
Daniel F. Sunday, Alexandros Chremos, Tyler B. Martin, Alice B. Chang, Adam B. Burns, Robert H. Grubbs
Bottlebrush polymers consist of a linear backbone with densely grafted sidechains which impact the rigidity of the molecule. The persistence length of the bottlebrush backbone in solution is influenced by both the intrinsic structure of the polymer and by

Bayesian Hierarchical Models for Service Life Prediction of Polymers

August 5, 2020
Author(s)
Adam L. Pintar, Christopher C. White, Li Piin Sung
Service life prediction for polymers remains an elusive goal. In this chapter, a general methodology first described in a previous study \cite{pintar2018predicting} is recapitulated and extended. A central component of the methodology is a Bayesian

Towards fast screening of organic solar cell blends

August 5, 2020
Author(s)
Lee Richter, Artem Levistsky, Giovanni M. Matrone, Aditi Khirbat, Ilaria Bargigia, Xiaolei Chu, Oded Nahor, Tamar Segal-Perez, Adam Moule, Carlos Silva, Natalie Stingelin, Gitti L. Frey
The ever increasing library of materials systems developed for organic solar-cells, including highly promising non-fullerene acceptors and new, high-efficiency donor polymers, demands the development of methodologies that (i) allow fast screening of a
Displaying 226 - 250 of 1944
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