Biopolymer and Paper Analytics

The research in the group "Biopolymer and Paper Analysis" covers the entire spectrum of analytical questions related to lignocelluloses, especially cellulose, hemicelluloses, lignin and extractives. This refers both to the application of established methodology to investigate different types and tasks of polymers and to the development of new analytical techniques. A special focus is on modern cellulose and lignin analysis and its further development and application to current research in the field of lignocelluloses and new biomaterials.

Size Exclusion Chromatography (SEC) with multiple detection in combination with light scattering is the central tool in this context, for which several independent systems are available for routine analysis as well as for special purposes. SEC is also combined with different fluorescence labeling techniques to enable the detection of functional groups, substituents or structural units not only as sum parameters but also as profiles relative to the molecular mass distribution. In particular, the CCOA method for the quantification of carbonyl groups and the FDAM method for the determination of carboxyl groups have attracted great international attention and have found broad application in cellulose research. They are routinely used and further developed worldwide only here. These methods are particularly suitable for investigating oxidative changes in cellulosic and polysaccharide substrates. Especially the effects of processing, environmental stress or aging can be studied in detail.

The area of lignin analysis focuses in particular on the development of new, fast analytical methods for technical lignins in order to support current research regarding quality and suitability in novel applications. Multidimensional chromatography applications (2D) allow new insights into structure-property-application relationships of technical lignins. Novel products based on technical lignins are a closely related field of research in which the group is active.
For extractives, analytical methods based on HT-GCMS and UPC2-qTof MS are developed and tested. Here the focus is on the analysis and use of bark and related biomaterials.

All of these analytical methods can be used in an extremely versatile manner for all facets of investigation, modification and applications of renewable raw materials. Lignocellulose and process characterization in biorefineries require a reliable and robust technology for which chemometric methods help to establish fast and robust analytical procedures. This is supported by two comprehensive databases containing more than 500 different pulps and cellulose samples and more than 500 different lignins.

Interesting applications of lignocellulose chemistry and analysis are established within the framework of modern conservation science, supported by numerous international cooperations with libraries, archives, galleries and museums. Here we are dealing on the one hand with molecular mechanisms of cellulose aging and their applications, and on the other hand with damage assessment and limitation in historical cellulosic substrates. This includes paper deacidification, ink and copper corrosion, fire damage and conservation countermeasures as well as the evaluation of conservation treatments with respect to their cellulose stabilization and sustainability. Numerous "exotic" cellulosic products (e.g. medieval manuscripts, papyri, Inca-Qipus, Korean annals) have been the guests in our lab for such studies.