Area 2 - Advanced characterization

RCA-Leader: Aleksandar Matic

The Advanced characterization area primarily combines nuclear magnetic resonance spectroscopy (NMR) and wide- and small angle X-ray scattering (WAXS and SAXS) to answer: How does the lignocellulosic structure look after modification and processing on nanometre to micrometre scale? How does it change during the modifications?

Objectives 

(i) apply WAXS-/SAXS-based 2D and 3D imaging methods to lignocellulose to obtain spatially resolved structures (on nm to mm scales) of starting and modified materials

(ii) implement advanced NMR methods such as dynamic nuclear polarization -NMR in the characterization of lignocellulose starting materials (to determine nanoscopic location of the substituents)

(iii) develop approaches for in-situ studies 

(iv) mimicking processing conditions to understand materials structure during e.g. flow and thermal gradients

(v) develop methods (e.g. x-ray scattering combined with NMR) able to reveal spatially resolved structural information (nm to mm length scales) 

(vi) develop methods to determine chemical domain sizes of heterogeneous modified lignocellulose

Motivation and description of the activities 

This RCA will support the entire project with high-resolution (spatial and chemical) characterization which will allow for a unique understanding of the interplay between chemical modification and morphology, and the thermoplastic properties of the material.
 

The new synchrotron source in Sweden, MAX IV, with its world-leading beam characteristics in terms of brilliance and coherence, has a large potential to be implemented in FibRe. On the nanometre scale, ptychographic tomography can provide 3D information, down to 14 nm resolution, and can also be combined with X-ray fluorescence mapping (XRF) to obtain elemental information. On a meso-scale, X-ray tomographic microscopy (XTM) allows fast measurements suitable for in-situ studies. Scanning SAXS experiments can reveal hierarchical structures with nanometre information over extended sample areas, which can also be performed in 3D. There is a large potential in applying these techniques to characterize and follow changes in the structure in-situ during processing. Through the framework of Treesearch we will also have access to the new ForMAX instrument at MAX IV (from 2022), with both SAXS/WAXS and tomography capabilities as well as tailored sample environment for research on lignocellulose materials. Collaboration with the Centre of X-ray Analytics at EMPA (Swiss Federal Laboratories for Materials Science and Technology), Switzerland, further broadens the competence and instrument portfolio, for example by X-ray imaging, scattering or diffraction measurement during in-situ mechanical testing relevant for testing processing and final properties of the materials.
 

Similarly, the advancement in NMR will be brought into research of thermoplastic lignocellulose-based materials. CP/MAS 13C-NMR methods have been developed to characterize the supramolecular structure of cellulose on a length scale from about 1 to 100 nm. By combining SAXS and CP/MAS (Cross-Polarization Magic Angle Spinning) 13C-NMR a more complete nanostructure characterization is obtained. It is also worth mentioning that the simultaneous access to both CP/MAS 13C-NMR spectroscopy, SAXS/WAXS scattering techniques, with the associated competences, is globally very rare and represents a valuable asset in FibRe. In addition, DNP-NMR extends the capabilities of solid-state NMR by providing a dramatically increased sensitivity (~100 times) enabling e.g. detection of low degrees of substitution, and also previously inaccessible studies of interfacial phenomena, at reasonable experimental time.

 

 
U. Vogt; K. Parfeniukas; T. Stankevič; S. Kalbfleisch; M. Liebi; Z. Matej; A. Björling; G. Carbone; A. Mikkelsen; U. Johansson “First X-ray nanoimaging experiments at NanoMAX”  X-Ray Nanoimaging: Instruments and Methods III, SPIE 2017, 10389, 103890K
 
F. Schaff, M. Bech, P. Zaslansky, C. Jud, M. Liebi, M. Guizar-Sicairos & F. Pfeiffer “Six-dimensional real and reciprocal space small-angle X-ray scattering tomography” Nature 2015, 527, 353-35
 
 

Page manager Published: Fri 23 Sep 2022.