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Search Publications by: Xiaohong Gu (Fed)

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Displaying 26 - 50 of 68

NIST Sustainable Infrastructure Material Program

March 17, 2010
Author(s)
Jonathan W. Martin, Xiaohong Gu, Tinh Nguyen, Joannie W. Chin
NIST has initiated a research program for improving the quality of the data input for making economic sustainability assessments of polymeric infrastructure materials through improvements in the measurement science for this data. Sustainability assessments

Studying Long-term Performance of a Nano-ZnO filled Waterborne Polyurethane Coating using Spectroscopies and Microscopies

September 9, 2009
Author(s)
Xiaohong Gu, Dongmei Zhe, Stephanie S. Watson, Guodong Chen, Minhua Zhao, Paul E. Stutzman, Deborah S. Jacobs, Tinh Nguyen, Joannie W. Chin, Jonathan W. Martin
Although inorganic UV absorbers such as zinc oxide (ZnO) and cerium oxide (CeO2) exhibit numerous advantages compared to organic UV absorbers, the mechanisms of how these nanoparticles affect the long-term performance of polymeric coatings are less than

Degradation and Nanofiller Release of Polymer Nanocomposites Exposed to UV

July 15, 2009
Author(s)
Tinh Nguyen, Bastien T. Pellegrin, Alexander J. Shapiro, Xiaohong Gu, Joannie W. Chin
Nanofillers are increasingly used to enhance multifunctional properties of polymers. However, recent research suggests that nanomaterials may have a negative impact on the environmental health and safety. Since polymers are susceptible to photodegradation

Long-Term Performance of Nano-Filled Polymeric Materials: Effect of ZnO Nanoparticles on Photodegradation of a Waterborne Polyurethane Coating

July 8, 2009
Author(s)
Xiaohong Gu, Dongmei Zhe, Minhua Zhao, Guodong Chen, Nhieu Ly, Paul E. Stutzman, Li Piin Sung, Tinh Nguyen, Joannie W. Chin
Polymers are widely used as exterior coatings in buildings, bridges, aircrafts and automobiles for both protection and aesthetic purposes. However, the service life of the applied coatings is limited due to the photodegradation of polymers induced by

Linking Accelerated Laboratory Test with Outdoor Performance Results for a Model Epoxy Coating System

October 8, 2008
Author(s)
Xiaohong Gu, Deborah S. Jacobs, Walter E. Byrd, Brian Dickens, Iliana Vaca-Trigo, William Meeker, Tinh Nguyen, Jonathan W. Martin
Laboratory and field exposure results have been successfully linked for a model epoxy coating system. The mathematical model used in making this linkage only assumed that the total effective dosage, additivity law, and reciprocity laws were valid. In this

Chemical and Physical Characterization of Poly(p-phenylene benzobisoxazole) Fibers Used in Body Armor

May 1, 2006
Author(s)
Joannie W. Chin, E Byrd, Amanda L. Forster, Xiaohong Gu, Tinh Nguyen, Kirk D. Rice, Walter J. Rossiter Jr, S J. Scierka, John R. Sieber, Paul E. Stutzman, Li Piin Sung
Problems with the performance and durability of body armor based on poly(p-phenylene benzobisoxazole (PBO) fiber became apparent in the summer of 2003, when PBO-based body armor that was less than 8 months was penetrated by a bullet. Mechanical testing of

Effects of Surface Functionality and Humidity on The Adhesion Force and Chemical Contrast Measured With AFM

January 1, 2005
Author(s)
Tinh Nguyen, Xiaohong Gu, lijiang chen, Michael J. Fasolka, Kimberly Briggman, Jeeseong C. Hwang, Jonathan W. Martin
The ability to probe chemical heterogeneity with nanometer scale resolution is essential for developing a molecular level understanding of a variety of phenomena occurring at surfaces of materials. One area that could benefit greatly from nanoscale

Advanced Techniques for Nanocharacterization of Polymeric Coating Surfaces

July 1, 2004
Author(s)
Xiaohong Gu, Tinh Nguyen, Li Piin Sung, Mark R. VanLandingham, Y C. Jean, Jonathan W. Martin
The applications of AFM and nanoindentation on study of surface property of polymeric coatings have been demonstrated. The surface microstructure of several coatings was characterized using tapping mode AFM, and the morphological change of coatings during

Surface and Interface Properties of UV-Exposed PVDF/PMMA-CO-PEA Blends

March 5, 2003
Author(s)
Xiaohong Gu, Li Piin Sung, D L. Ho, Chris A. Michaels, D Nguyen, Y C. Jean, Tinh Nguyen
The surface and interface of PVDF blended with different amounts of poly (methyl methacrylate) and poly (ethyl acrylate) copolymer (PNMA-co-PEA) have been investigated before and after exposure to UV light. Dry free films having athickness of approximately

Nanoscale Chemical Imaging of Polymeric Materials With Atomic Force Microscopy

February 26, 2003
Author(s)
Xiaohong Gu, Tinh Nguyen, Michael J. Fasolka, D Julthongpiput, Lei Chen, Mark R. VanLandingham, Y C. Jean, Jonathan W. Martin
Nanoscale spatial chemical information is essential to developing a molecular-level understanding of a variety of phenomena occurring at surfaces and interfaces, including adhesion, friction, and surface reactivity. Therefore, the ability to probe and

Hole Growth Instability in the Dewetting of Evaporating Polymer Solution Films

December 1, 2002
Author(s)
Xiaohong Gu, D T. Raghavan, Jack F. Douglas, Alamgir Karim
We investigate the dewetting of aqueous, evaporating polymer [poly(acrylic acid)] solutions cast on hydrophobic (polystyrene) substrates. As with typical dewetting, the evaporating films initially break up through the nucleation of holes that perforate the

Surface and Interface Properties of PVDF/Acrylic Copolymer Blends

November 1, 2002
Author(s)
Xiaohong Gu, Tinh Nguyen, Mark R. VanLandingham, D Nguyen
Poly(vinylidene fluoride) (PVDF) is commonly blended with amorphous polymers to improve its optical property. The surface and interface properties of PVDF blended with different amounts of poly(methyl methacrylate) and poly(ethyl acrylate) copolymer (PMMA