This study is developed in the framework of RéCaMiA, a French regional (Rhône-Alpes / Auvergne) microscopy network, which offers facilities through a panel of microscopes such as SEM, TEM, FIB, AFM, Confocal.

The objective of the study is to compare results obtained with different microscopy techniques currently employed in three-dimensional imaging, but it focuses more specifically on polymers [1-3]. For the purpose a blend of polystyrene / acrylonitrile butadiene styrene (PS/ABS) is chosen. This material allows to obtain good contrast in SEM or TEM; microstructural features exist at the submicronic and nano scales; and its glass transition temperature T_g is above 50°C. Two samples are stained by contact with a 4% osmium tetraoxide (OsO₄) water solution to reveal contrasts. 2 FIB–SEM (FEI Helios600, Zeiss NVisio40 dual beam), 2 TEM (JEOL JEM 1400, JEOL 2100F), 2 SEM (FEI ESEM XL30, FEI Quanta250) are used to study the 3D structure of the polymer. This study develops a multiscale approach. The tools used require 2 different procedures to get a 3D image: (a) to acquire a stack of individual imaging planes and to transform it into the corresponding 3D data volume or (b) to perform electron tomography. In the first case individual images are obtained through a slice and view approach in FIB, or through individual observations, in SEM or TEM, of several thin foils prepared by ultramicrotomy method at room temperature (serial sectioning). Backscattered electron images are collected. The 3D reconstructions of the polymer obtained by the different tools are compared each other. Whatever the approach used, the morphology “salami” shape is observed in the structure of the polymer. Structure parameters, such as size distribution of the nodules and the anisotropy coefficient, are extracted and compared. Different test parameters effects are investigated, the preparation of the sample (compression of the microstructure more or less), the voltage, the spacing between the individual imaging planes, etc. The balance between the reconstructed volume size, the voxel resolution, the total time to get the 3D data volume, the advantages and limitations of the methods used in this multiscale approach will also be discussed.

[1] M. Kato et al., Journal of Polymer Science: Part B: Polymer Physics, Vol. 45, 677–683 (2007)
[2] S. Sinha Ray, Polymer 51 (2010) 3966-3970
[3] P. Jornsanoh et al., Ultramicroscopy 111(2011)1247–1254

Acknowledgements            

Thanks are due to CNRS for its financial support. Thanks are due to CLYM (Consortium Lyon – St-Etienne de Microscopie, www.clym.fr) funded by the Region Rhône-Alpes, the CNRS and the ‘GrandLyon’, for the access to the Zeiss NVisio40 and XL30; and also to Manutech-USD for the access to the FEI Helios600.

Figures:

Fig. 1. SEM images (serial sectioning) and 3D reconstruction (volume of 7x9x0.8 µm3)

Fig.2. 3D reconstruction volume obtained by slice and view in FIB-SEM

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EMC Abstracts - https://emc-proceedings.com/abstract/3d-investigation-of-a-psabs-polymer-using-different-microscopy-techniques/