Take a sneak peek at the new NIST.gov and let us know what you think!
(Please note: some content may not be complete on the beta site.).
NIST Authors in Bold
|Author(s):||Xiaohong Gu; Guodong Chen; Minhua Zhao; Stephanie S. Watson; Tinh Nguyen; Joannie W. Chin; Jonathan W. Martin;|
|Title:||Critical Role of Particle/Polymer Interface in Long-term Performance of Nanofilled Polymeric Coatings|
|Published:||May 17, 2010|
|Abstract:||In this study, the role of the nanoparticle/polymer interface in the long-term UV weathering performance of a nano-ZnO filled polyurethane (PU) coating system was investigated. The effects of the parameters that can influence the particle/polymer interfacial properties, such as size, loading, surface modification of the nanoparticles, on photodegradation of ZnO/PU films were evaluated. The nature of the interfacial regions before and after UV exposures were characterized by atomic force microscopy (AFM)-based techniques. Results have shown that the interfacial properties strongly affect chemical, thermo-mechanical and morphological properties of the UV-exposed ZnO/PU films. By combining tapping mode AFM and novel electric force microscopy (EFM), the particle/polymer interfacial regions have been successfully detected directly from the surface of the ZnO/PU films. Further, our results indicate that ZnO nanoparticles can function as a photo-catalyst or a photo-stabilizer, depending on the UV exposure conditions. A hypothesis is proposed that the polymers in the vicinity of the ZnO/PU interface are preferentially degraded or protected, depending on ZnO nanoparticles act as a photo-catalyst or a photo-stabilizer in the polymers. This study clearly demonstrates that the particle/polymer interface plays a critical role in the long-term durability of nano-filled polymeric coatings.|
|Conference:||American Coatings Show 2010|
|Dates:||April 12-14, 2010|
|Research Areas:||Service Life Prediction|