Seminars Archive
Raman spectroscopy at the University of Salzburg
Department of Chemistry and Physics of Materials, Division of Physics and Biophysics, University of Salzburg, Austria
Abstract
Raman spectroscopic studies for the characterization of condensed matter is routinely performed at the Department of Chemistry and Physics of Materials of the University of Salzburg since several years [1], and some of the more recent results deal with polymeric [2-3] and with biogenic materials [4].
Raman spectroscopic investigation of tannin-furanic foam and its precursor materials has been performed with three laser wavelengths at 1064, 532, and 455 nm, the aim being to establish a tool complementary to infrared spectroscopy for comparing their spectral signature with that of the precursor materials furfuryl alcohol, polymerized furfuryl alcohol, and Mimosa tannin [2], and to discuss similarities and differences to the spectral signatures of sp2 carbon-based materials, the still preserved organic nature of the tannin-furanic foam, and similarities and differences to recently reported infrared spectra.
When the temperature of a semi-crystalline polymer sample like Nylon 6/6 increases up to the melting point, some relaxations processes caused by thermally activated molecular rearrangements can happen in the form of conformational changes and microscopic deformations. Associated with these relaxation processes are variations in the thermal, mechanical and dielectric properties of the polymer sample, enabling their detection. Raman spectroscopy has been used as an additional tool to determine the temperature ranges where relaxation processes in Nylon 6/6 get activated, which result to be in reasonable agreement with values reported from measurements of thermal, mechanical, and dielectric properties [3].
The ability of bone graft substitutes to promote new bone formation has been increasingly used in the medical field to repair skeletal defects or to replace missing bone in a broad range of applications in dentistry and orthopedics. A common way to assess such materials is via micro computed tomography (µ-CT), through the density information content provided by the absorption of X-rays. Information on the chemical composition of a material can be obtained via Raman spectroscopy. By investigating a bone sample from miniature pigs containing the bone graft substitute Bio Oss®, we pursued the target of assessing to what extent the density information gained by µ-CT imaging matches the chemical information content provided by Raman spectroscopic imaging [4].
REFERENCES
[1] M. Musso, K.L. Oehme, Raman spectroscopy, in: M. Lackner (Ed.), Lasers in Chemistry: Probing and Influencing Matter, Wiley-VCH, Weinheim, 2008, pp. 531–591.
[2] A. Reyer, G. Tondi, R.J.F. Berger, A. Petutschnigg, M. Musso, Raman spectroscopic investigation of tannin-furanic rigid foams, Vibrational Spectroscopy 84 (2016) 58-66
[3] D. Bertoldo Menezes, A. Reyer, A. Marletta, M. Musso, Determination of the temperatures of the ?, ß and a relaxation processes in Nylon 6,6 by Raman Spectroscopy, submitted.
[4] J. Charwat-Pessler, M. Musso, A. Petutschnigg, K. Entacher, B. Plank, E. Wernersson, S. Tangl, P. Schuller-Götzburg, A bone sample containing a bone graft substitute analyzed by correlating density information obtained by X-ray micro tomography with compositional information obtained by Raman microscopy, Materials 8 (2015) 3831-3853.
