Nuclear Magnetic Resonance Investigations on Structure and Functions of Complex Systems
(NMR)

Nuclear magnetic resonance (NMR) is a powerful tool in environmental engineering: the determination of molecular structures and dynamics, and the investigation of binding interactions or of the progress of (bio)chemical reactions are possible options of operation. In this project, complex and heterogeneous systems of organic, inorganic and biological materials get characterized by NMR-spectroscopy. The samples stem from environmental or technological processes. Structural data and mobility information expand the understanding of chemical and biological transformations, transport and adsorption phenomena.

Besides the Water Chemistry Division which has also the coordinating function, two other institutes of the university of Karlsruhe participate in this joint project: the Division Fuel Chemistry and Technology of the Engler-Bunte-Institut (Prof. Reimert) and the Bioprocess Engineering Division of the Institute for Mechanical Process Engineering and Mechanics (Prof. Posten). A new high-resolution 400 MHz NMR spectrometer (type AVANCE; BRUKER, Karlsruhe) was set up for the research studies. The spectroscopic equipment includes a CPMAS (cross polarization magic angle spinning) broadband double resonance probe for solid samples (maximum rotation frequency 15 kHz). A multinuclear (¹⁰⁹Ag to ³¹P) probe exists for the characterization of liquid samples.

The Division of Water Chemistry focuses on solid-state NMR spectroscopy of natural organic matter (NOM) of aquatic origin. The elucidation of chemical reactions, molecular interactions and the fractionation of NOM during water process operations like oxidation, ultrafiltration, flocculation and precipitation are of special interest.