Morphology, topography, crystal structure, chemical composition of polymers and composites - SEM/FIB/EDX

SEM imaging is an invaluable tool for the development and manufacture of polymer and composite products.

Polymers and plastics are characterized by a wide range of properties such as low thermal conductivity, corrosion resistance, lightness, formability and flexibility. Their main advantages include low density, chemical resistance, uniformity of composition and structure, and good processability. Composites are materials generally made up of two macroscopic phases, which have different physical and chemical properties and a recognizable interface between them. Polymers are widely used in a range of industries, including food packaging, automotive and electronics.

The wide range of composite materials requires a variety of analyses of varying complexity, as well as regular checks to ensure that finished products comply with specifications.

Identification and determination of polymer chemical composition, nature, mechanical and thermal properties, conformity verification... Physicochemical analysis is a key tool in the development and manufacture of polymer-based products and composites. Scanning Electron Microscopy (SEM) is used to identify the morphology and structure of these materials. The dual-beam FIB-MEB system provides invaluable information on the subsurface of materials, enabling 3D visualization of the spatial distribution of the phases present.
SEM is a technique capable of producing high-resolution images of the surface of a sample. It is used in many fields, from biology to materials science and microelectronics, and on all types of sample. Even insulating materials can be observed after metallization, in a controlled inert atmosphere or at low voltages (close to kV).

SEM is generally used to study the 3D morphology of a surface or object with nanometric resolution. Elemental chemical composition can also be obtained by X-ray microanalysis.

The principle of this technique is based on the use of an incident electron beam of a few tens of kilovolts scanning the surface of the sample, which then re-emits a whole spectrum of particles and radiation: secondary electrons, backscattered electrons, Auger electrons and X-rays. Detection of the various particles or radiation emitted provides information about the sample: its morphology, topography, crystalline structure, elemental chemical composition (qualitative and semi-quantitative analysis)...

TESCAN ANALYTICS has over 30 years' expertise in the use of SEM/FIB/EDX on all types of materials, whether insulating or conductive... With state-of-the-art instruments, our team of experts works with all industrial sectors.

Objective of the analysis


Obtain key information on the morphology, topography, crystalline structure and elemental chemical composition of plastic and composite materials.

Sample preparation


Specific preparations can be carried out for each type of sample:
- Metallization of insulating samples
- Resin coating and microtomy surfacing of organic and biological samples
- FIB cross-sectioning for cross-sectional or 3D visualization of materials


Results


 
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Figure 1 : SEM image of polyurethane foam cells - uncoated sample (LVSTD)
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Figure 2 : Polystyrene - fracture surface (overview)

 
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Figure 3 : Polystyrene - breaking surface (detail)
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Figure 4 : SEM image of polymer fibers
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Figure 5 : SEM image of gel (overview)
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Figure 6 : SEM image of gel (detail)
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Figure 7 : 3D FIB SEM reconstruction of an epoxy resin-coated woven glass fiber composite (segmentation of pores and defects).
 
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Figure 8 : 3D reconstruction of composite fibers (pore segmentation)


Summary


These non-exhaustive examples demonstrate that scanning electron microscopy (SEM), with or without FIB and EDX, is an ultra-powerful microscopy tool for the structural and chemical study of polymers and composites.

With an excellent depth of field (~ 100 x that of optical microscopy), SEM provides high-resolution images of all materials.

For more applications of SEM analysis or our other analytical techniques and microscopy, click here.

The combination of SEM/EDX and ToF-SIMS techniques facilitates comprehensive analysis of material composition. X-ray tomography enables non-destructive visualization of internal features such as porosity, cracks and phase distribution. In dynamic mode, it is possible to visualize 3D changes in internal structures when they undergo modifications such as loading or liquid absorption.