PHYSICO-CHEMICAL CHARACTERIZATION

Description

The PC2 Platform is constituted by a large park of instruments including: nuclear magnetic resonance (both liquid and solid state) spectrometers, single-crystal and powder X-ray diffractiometers, instruments for the analysis of the textural properties (N2 physisorption, mercury porosimetry, …) and for the chemical composition (combustion chemical analysis, ICP, …) as well as separation techniques (chromatography, centrifugation…).

The combination of these techniques together with the presence of 2 technicians full time dedicated to the analysis of the samples and highly qualified researchers for the development of advanced applications represent a strategic feature of this platform. Among these characterization techniques solid state NMR and X-ray diffraction emerged as advanced tools for characterization.

The platform is active in collaboration with academic teams, both at a national and international level. It also has a tradition of fruitful collaborations with industrial partners, especially in the fields of materials sciences and with the food and pharmacological industries.

Equipment

Single-crystal & powder X-ray diffractometers

Dr Nikolay Tumanov, Research Logistician, is in charge of crystallography, where two X-ray diffraction instruments – diffractometers – are available: they are dedicated to two different techniques: single-crystal diffraction and powder X-ray diffraction.  

For single-crystal X-ray diffraction a small crystal of the sample is needed.  The analysis gives the full crystalline structure of the investigated compound i.e. coordinates of all atoms and absolute configuration.

Powder X-ray diffraction requires powder samples and is used for the investigation of different types of solids: pharmaceuticals, polymers, nanomaterials, glass. As a routine, this method can give the composition of the investigated material.

But using the combination of advanced powder diffraction methods with solid-state NMR and quantum chemistry calculations enables the determination of the crystalline structure directly from the sample.

Elemental analysis

The instrument allows the fast determination of the content in carbon, hydrogen, nitrogen, sulphur or oxygen in organic matters and other types of materials.  This analysis is based on the total combustion of the material at 940°C (under a flow of oxygen and pressure).

The carbon, hydrogen, nitrogen and sulphur in the samples are transformed into carbon dioxide, water, nitrogen dioxide and sulphur dioxide respectively. A chromatographic column separates these products, which are measured by a heat conduction detector.

ICP

Optical Emission Spectrometry coupled with Inductively Coupled Plasma (ICP-OES) is based on the thermal excitement of ions in plasma and the analysis of the light emitted by these ions. Every element emits characteristic wavelengths. The wavelengths are then separated, identified and their intensities measured by a spectrometer. The elementary concentration is determined by comparison to an external calibration.

Nuclear Magnetic Resonance (270, 400 & 500 MHz)

Dr Luca Fusaro, Research Logistician, is in charge of the development of the use of Nuclear Magnetic Resonance (NMR) at the University of Namur. He collaborates with other researchers, helping them to obtain insights about variousdifferent systems.

In particular one of the most active field is solid state NMR, which is used to study a broad range of organic, inorganic materials, catalysts, glass. The standard nuclei are 13C, 27Al, 29Si, but more advanced applications are also used to study species which are often diluted , such as 67Zn, 71Ga, 119Sn.

Measurements at variable temperatures can also be performed with the available NMR equipment.