Chemical Mapping of Polymer Microstructure Using Soft X-ray Spectromicroscopy*

Adam P. Hitchcock; Harald D. H. Stöver; Lisa M. Croll; Ronald F. Childs

doi:10.1071/CH05054

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Chemical Mapping of Polymer Microstructure Using Soft X-ray Spectromicroscopy*

Adam P. Hitchcock ^A ^B , Harald D. H. Stöver ^A , Lisa M. Croll ^A and Ronald F. Childs ^A

+ Author Affiliations

- Author Affiliations

^A Chemistry and the Brockhouse Institute for Materials Research, McMaster University, Hamilton, Ontario L8S 4M1, Canada.

^B Corresponding author. Email: aph@mcmaster.ca

Adam Hitchcock’s research involves developing instrumentation and techniques to apply inner shell excitation spectroscopies and microscopies to a wide range of chemical and materials analysis problems. After completing a Ph.D. and postdoctoral fellowship in chemical physics at the University of British Columbia, he joined the Chemistry department and BIMR at McMaster University in 1979. In 2000 he was appointed to a tier 1 Canada Research Chair.

Harald Stöver’s research explores new routes to microstructured polymer spheres and capsules of relevance to controlled release, optics, and bio-technology. After undergraduate studies at the University of Darmstadt, he obtained his Ph.D. from the University of Ottawa and carried out post-doctoral research at Cornell University. He joined McMaster in 1989 and held an NSERC-3M Canada Industrial Research Chair from 1998 to 2003.

Lisa Croll carried out her Ph.D. research on the development of the tectocapsule technology under the direction of Harald Stöver. This work combined microsphere self-assembly at interfaces with polyurea encapsulation and STXM analysis. She graduated in 2004 and is currently working as a Senior Chemist in the Occupational Health and Environmental Safety Laboratory at 3M Canada.

Ron Child’s current research is focussed on the development of improved membranes for industrial water treatment, and biomedical applications. He obtained a Ph.D. and D.Sc. in chemistry at the University of Nottingham, and has been a professor of chemistry at McMaster University since the late 1960s. Although formally retired he maintains a very active research program, which includes establishment of spin-off companies.

Australian Journal of Chemistry 58(6) 423-432 https://doi.org/10.1071/CH05054
Submitted: 18 February 2005 Accepted: 15 April 2005 Published: 14 June 2005

Abstract

Recently, synchrotron-based soft X-ray spectromicroscopy techniques have been applied to studies of polymer microstructure at the ~50 nm spatial scale. Functional group based chemical speciation and quantitative mapping is provided by near edge X-ray absorption fine structure spectral (NEXAFS) contrast. The techniques, sample data, and analysis methods of scanning transmission X-ray microscopy (STXM) and X-ray photoemission electron microscopy (X-PEEM) are outlined. The capabilities of STXM are illustrated by results from recent studies of (a) controlled release microcapsules and microspheres, (b) microcapsules being developed for gene therapy applications, (c) conducting polymer films studied in the presence of electrolyte and under potential control, and (d) studies of protein interactions with patterned polymer surfaces. In the latter area, the capabilities of STXM and X-PEEM are compared directly.

Measurements were performed at beamlines 5.3.2 (STXM) and 7.3.1 (PEEM) at the Advanced Light Source. The ALS is funded by the Department of Energy under contract DE-AC03-76SF00098. Zone plates are provided by Center for X-Ray Optics (CXRO) at the Lawrence Berkeley National Laboratory (LBNL). We thank the LBNL staff scientists (Tolek Tyliszczak and David Kilcoyne for STXM, Andreas Scholl and Andrew Doran for X-PEEM) for their assistance and expert support of the instrumentation, and Marcia West (McMaster) for masterful microtomy. Research supported by the National Sciences and Engineering Council of Canada (NSERC) and the Canada Research Chair program.

References

^* Based on a keynote talk at the 27th Australasian Polymer Conference, Adelaide, 29 November–2 December 2004.

^† www-als.lbl.gov/als/

^‡ www.lightsource.ca

Chemical Mapping of Polymer Microstructure Using Soft X-ray Spectromicroscopy*

Abstract

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