skip to main content

SciTech ConnectSciTech Connect

Title: Radiation damage in polymer films from grazing-incidence X-ray scattering measurements

Grazing-incidence X-ray scattering (GIXS) is widely used to analyze the crystallinity and nanoscale structure in thin polymer films. However, ionizing radiation will generate free radicals that initiate cross-linking and/or chain scission, and structural damage will impact the ordering kinetics, thermodynamics, and crystallinity in many polymers. We report a simple methodology to screen for beam damage that is based on lithographic principles: films are exposed to patterns of x-ray radiation, and changes in polymer structure are revealed by immersing the film in a solvent that dissolves the shortest chains. The experiments are implemented with high throughput using the standard beam line instrumentation and a typical GIXS configuration. The extent of damage (at a fixed radiation dose) depends on a range of intrinsic material properties and experimental variables, including the polymer chemistry and molecular weight, exposure environment, film thickness, and angle of incidence. The solubility switch for common polymers is detected within 10-60 sec at ambient temperature, and we verified that this first indication of damage corresponds with the onset of network formation in glassy polystyrene and a loss of crystallinity in polyalkylthiophenes. Therefore, grazing-incidence x-ray patterning offers an efficient approach to determine the appropriate data acquisition times for any GIXS experiment.
Authors:
 [1] ;  [2] ;  [2] ;  [3] ;  [1]
  1. Univ. of Houston, Houston TX (United States). Dept. of Chemical and Biomolecular Engineering
  2. Univ. of Houston, Houston TX (United States). Dept. of of Electrical and Computer Engineering
  3. Argonne National Lab. (ANL), Argonne, IL (United States). X-Ray Science Division
Publication Date:
OSTI Identifier:
1267165
Grant/Contract Number:
AC02-06CH11357; CBET-1236606; DMR-1151468
Type:
Accepted Manuscript
Journal Name:
Journal of Polymer Science. Part B, Polymer Physics
Additional Journal Information:
Journal Volume: 54; Journal Issue: 11; Journal ID: ISSN 0887-6266
Publisher:
Wiley
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org:
National Science Foundation (NSF); USDOE Office of Science
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE beam damage; grazing incidence; radiation crosslinking; WAXS; irradiation; SAXS; crosslinking; block copolymers; conjugated polymers; x-ray