IR

Published: 14 October 2008

Research

Generally speaking, the aim of our research is to describe and explain the interactions occurring between solid surfaces, ions, and molecules in aqueous solution.

More specifically, our research is focused on interfaces between minerals and aqueous solutions that are of major interest for the Swedish mining and mineral industry, although it also encompasses minerals that have high porosity and because of that are suitable as e.g. sorbents, as well as surface properties that are able to show low friction coefficients.

The FTIR Spectroscopic technique is used in these studies utilizing the ATR method, which is suitable for in-situ measurements. ATR implies that the infrared radiation is attenuated, but totally reflected through the crystal material used and the in-situ possibility gives a high industrial relevance. Below, a simple sketch of the ATR principal is shown:

atr_01.jpg

By means of the infrared radiation you can ”see” the vibrations of atoms in molecules, multi-atom ions or solid surface complexes presupposed that they are close to the ATR-crystal ( ZnSe in the figure).

Accordingly, you can get information about the interaction between these species, but also study the orientation of molecules/particles attached to the mineral surface. The latter information demands polarized infrared light.

A detailed interpretation of IR spectra is rather complicated. That’s why the IR-group since many years has initiated collaboration with people specialized on theoretical calculations of vibration frequencies and the conformation of molecules attached to solid surfaces.

Instrument

There are spectrometers available not only for ATR but also for mid and far IR as well as FT-Raman and Raman microscopy:

Bruker IFS 66V/S Mid-, Far-IR
Perkin Elmer System 2000, Mid-IR
Perkin Elmer Raman 1760
Renishaw Raman microscope

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