NOTICE: Due to a lapse in annual appropriations, most of this website is not being updated. Learn more.

Form submissions will still be accepted but will not receive responses at this time. Sections of this site for programs using non-appropriated funds (such as NVLAP) or those that are excepted from the shutdown (such as CHIPS and NVD) will continue to be updated.

U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Xiaohong Gu (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 71

A Spatially-Resolved Evaluation of Accelerated Environmental Aging on Emerging Polypropylene-based Photovoltaic Backsheets using Raman Spectroscopy

March 13, 2025
Author(s)
Ashlee Aiello, Stefan Mitterhofer, Jan Obrzut, Karissa Jensen, Patryk Wasik, Chiara Barretta, Gernot Oreski, Stephanie Watson, Li Piin Sung, Xiaohong Gu
Accelerated aging was used to assess environmental degradation in emerging co-extruded polypropylene (PP)-based backsheets under three different environmental conditions (65 °C/20 % relative humidity (RH), 75 °C/20 % RH, and 75 °C/50 % RH). Although

PVDF-based Backsheet Cracking: Mapping In Situ Phase Evolution by X-ray Scattering

December 15, 2024
Author(s)
Stephanie Moffitt, Sona Ulicna, Song-Syun Jhang, Po-Chang Pan, Michael Owen-Bellini, Peter Hacke, Michael Kempe, Jared Tracy, Kaushik Choudhury, Laura Schelhas, Xiaohong Gu
One of the most common polymers in commercial photovoltaic (PV) backsheets is polyvinylidene fluoride (PVDF). However, recent reports have shown the potential for PVDF-based backsheets to crack and fail prematurely. Previous work has suggested that polymer

Surface photooxidation of polypropylene-based photovoltaic backsheets: A comprehensive spectroscopic investigation

December 8, 2024
Author(s)
Karissa Jensen, Ashlee Aiello, Stefan Mitterhofer, Chiara Barretta, Gernot Oreski, Christopher Stafford, Xiaohong Gu
The prospect of cost reduction, enhanced performance, and improved sustainability has been driving innovation in the development of new backsheet materials for photovoltaic (PV) modules in recent years. Among the materials of interest, polypropylene (PP)

Microstructure changes during failure of PVDF-based photovoltaic backsheets

July 21, 2022
Author(s)
Stephanie Moffitt, Po-Chang Pan, Lakesha Perry, Michael Kempe, Jared Tracy, Kaushik Choudhury, Xiaohong Gu
The backsheet layer of a solar module provides a safety and environmental barrier to the high voltages running through the photovoltaic (PV) cells and electrical contacts within the core of the module. However, in the past decade, backsheet cracking has

Study of Photodegradation of Epoxy Polymer by Using Slow Positron Annihilation Spectroscopy

October 12, 2021
Author(s)
R Zhang, Xiaohong Gu, H Chen, J Zhang, Y Li, Tinh Nguyen, T C. Sandreczki, Y C. Jean
Slow positron annihilation spectroscopy (SPAS) has been used to study the early stage of epoxy photodegradation. Spin-coated samples of a crosslinked epoxy were prepared by stoichiometrically mixing a diglycidyl ether of bisphenol A epoxy resin with 1,3

Graphene oxide/waterborne polyurethane nanocoatings: Effects of graphene oxide content on performance properties

January 15, 2020
Author(s)
David G. Goodwin, Coralie Bernard, Xiaohong Gu, Mat Celina, Marc R. Nyden, Deborah S. Jacobs, Li Piin Sung, Tinh Nguyen
Graphene oxide (GO) is a good nanofiller candidate for waterborne coatings because of its outstanding physical and mechanical properties, good dispersibility in water, and low cost. Here, we report on the performance of a one-part, water-borne polyurethane

Differential degradation patterns of photovoltaic backsheets at the array level

February 4, 2018
Author(s)
Andrew W. Fairbrother, Matthew Boyd, Yadong Lyu, Julien Avenet, Peter Illich, Michael Kempe, Brian P. Dougherty, Laura Bruckman, Xiaohong Gu
Photovoltaic backsheet degradation is commonly related to end-of-life failure of a module, and as such is an important factor in system reliability and longevity. Some module manufacturers have recently begun utilizing non-fluoropolymer-based backsheets in

Interlaboratory study towards a climate-specific test: spectroscopic characterizations of EVA in glass/EVA/glass systems

February 23, 2016
Author(s)
Jae Hyun Kim, Christopher M. Stafford, Yadong Lyu, Li C. Yu, Chiao-Chi Lin, Tinh Nguyen, Xiaohong Gu
EVA as an encapsulant material is exposed to various UV irradiation, thermal cycles, and humidity conditions. Degradation of EVA can reduce not only power generation due to yellowing, but also a structural integrity of a PV module. In order to investigate

New Insights into Subsurface Imaging of Carbon Nanotubes in Polymer Composites via Scanning Electron Microscopy

February 4, 2015
Author(s)
Minhua Zhao, Bin Ming, Jae-Woo Kim, Luke J. Gibbons, Xiaohong Gu, Tinh Nguyen, Cheol Park, Peter T. Lillehei, John S. Villarrubia, Andras Vladar, James A. Liddle
Despite many studies of subsurface imaging of carbon nanotube (CNT)-polymer composites via scanning electron microscopy (SEM), significant controversy exists concerning the imaging depth and contrast mechanisms. We studied CNT-polyimide composites and, by

A Quantitative Study of Nanoparticle Release from Nanocoatings Exposed to UV Radiation

April 7, 2014
Author(s)
Li Piin Sung, Deborah S. Jacobs, Justin M. Gorham, Savelas A. Rabb, Xiaohong Gu, Lee L. Yu, Tinh Nguyen
Nanoparticles are increasingly used in polymer coatings (i.e., nanocoatings) to improve multiple properties of traditional coatings such as mechanical, electrical, gas barrier, and UV resistance. These high performance nanocoatings are often used in

Characterization of Surface Accumulation and Release of Nanosilica During Irradiation of Polymer Nanocomposites with Ultraviolet Light

August 12, 2012
Author(s)
Tinh Nguyen, Bastien T. Pellegrin, Coralie Bernard, Savelas A. Rabb, Paul E. Stutzman, Justin M. Gorham, Xiaohong Gu, Lee L. Yu, Joannie W. Chin
Nanofillers are increasingly used for enhancing multiple properties of polymeric materials in many applications. However, polymers are susceptible to photodegradation by solar ultraviolet (UV) radiation Therefore, nanofillers in a polymer nanocomposite

More Durable or Vulnerable? --- Effect of Nanoparticles on Long-Term Performance of Polymeric Nanocomposites during UV Exposure

July 2, 2012
Author(s)
Xiaohong Gu, Minhua Zhao, Stephanie S. Watson, Tinh Nguyen, Joannie W. Chin, Jonathan W. Martin, Dongmei Zhe, Guodong Chen
Polymers are widely used as exterior coatings in buildings, bridges, aircrafts, and automobiles for both protection and aesthetic purposes. However, the sustainability and service life of the applied coatings is limited due to the photodegradation of

Fate of nanoparticles during life cycle of polymer nanocomposites

July 6, 2011
Author(s)
Tinh Nguyen, Bastien T. Pellegrin, Coralie Bernard, Xiaohong Gu, Justin M. Gorham, Paul E. Stutzman, Deborah S. Jacobs, Walter E. Byrd, John W. Hettenhouser, Joannie W. Chin
Nanoparticles are increasingly used in consumer and structural polymeric products to enhance a variety of properties. Under the influences of environmental factors (e.g., ultraviolet, moisture, temperature) and mechanical actions (e.g., scratching

Role of Nanoparticles in Life Cycle of Nanocomposites

June 15, 2010
Author(s)
Xiaohong Gu, Guodong Chen, Minhua Zhao, Stephanie S. Watson, Paul E. Stutzman, Tinh Nguyen, Joannie W. Chin, Jonathan W. Martin
The objective of this study is to investigate the role of ZnO nanoparticles in the life cycle of a waterborne polyurethane (PU) nanocomposite during UV exposure. The effects of loadings and sizes of ZnO nanoparticles on photodegradation of ZnO/PU films
Was this page helpful?