The great strength of microscopy is its versatility, which means that it can be used in a variety of ways depending on the task at hand.
Optical microscopy offers various contrast options (reflected light, transmitted light, bright field, dark field, polarization and interference contrast, fluorescence). A hot-stage microscope with an operating range from -190 °C to 500 °C combined with a calorimeter (DTA) is used to investigate e.g. crystallization processes. The results are documented with a digital image recording or video clip. Combining the scanning stage on the optical microscope with automatic image analysis means that automated enumerations can be carried out on e.g. particle sizes and fiber lengths (glass fiber length distribution).
Scanning electron microscopy (SEM) covers the options of taking measurements in a high vacuum, low vacuum and in a humid sample chamber (ESEM). A field emission cathode is used in this process. Energy dispersive X-ray spectroscopy (EDX) is integrated into the systems so that locally resolved element analyses on everything from carbon to uranium can be carried out simultaneously. An adaptable heating and cooling stage (- 40°C to 1000°C) can be used to study temperature effects in detail.
The combination of scanning and transmission electron microscopy (STEM) results in high-resolution images of pigments and nano particles. High-angle annular dark-field (HAADF) imaging produces material contrast images in transmission.
Particle size distribution, granulometry and pore size analysis can be carried out by combining the electron microscope with automatic image analysis.
Atomic force microscopy (AFM) measures both topography and a range of material contrasts (phase contrast, adhesion, friction, stiffness, magnetic contrasts, relative surface potential). TUNA is used to create a current image that maps the electrical conductivity within a sample. Quantitative atomic force microscopy supplies high-resolution absolute values on a nanoscopic scale for the modulus of elasticity and loss tangents within a sample. By combining AFM with automatic image analysis, it is possible to determine boundary layers around filler particles in thermoplastic and rubber matrices (e.g. bound rubber).
Optical spectroscopy in the field of infrared, Raman and UV/VIS spectroscopy is combined with microscopic techniques. This helps determine the integral, spectral information and the spatially-resolved chemical composition of samples. For example, the high-resolution ATR (attenuated total reflection) technique in the infrared microscope (µIR) can be used to depict the distribution of organic components in the form of chemical imaging.
Micro X-ray diffractometry with copper Kα radiation and area detection is used for defect analyses (µXRD) and spatially-resolved crystallinity determinations on e.g. thermoplastics and for non-destructive computer tomography (µCT) with three-dimensional insights into test specimens (e.g. molded parts, tablets) of up to 10x10x10 mm3. Powder diffractometry (XRD) is used for the phase, texture and crystallite size analysis of e.g. pigments.