In addition to the optical and electron microscopy facilities with various imaging modes to investigate a sample in microspace (1 m = 10-6 m) and nanospace (1 nm = 10-9 m), MAC-Twente offers a variety of chemical analysis techniques to explore the surface and internal structure of a specimen. Most of the techniques are commonly used to study inorganic materials but some of these can be used on specimens of organic nature too. The chemical analysis techniques offered by MAC-Twente will, e.g., give the elemental composition and in some cases also the chemistry of shallow surfaces of the sample and its bulk. Knowledge of the chemical constitution of the surface is required in areas such as adhesion, catalysis, photonics and chemical modification. Analyses can be done on scales from nanometres to micrometres in the normal direction, and from nanometres to millimetres in the lateral direction. Concentrations can be determined down to 0.1 atomic % . The MAC-Twente analysis facilities are completed by technologies for characterisation of samples in liquid
Scanning X-ray photoelectron spectroscopy (XPS)
exploring the top atomic layers
XPS, for microscopic elemental mapping of nm thick layers, powders. Composition and chemistry by measuring spectra and chemical shifts .
Energy dispersive X-ray analysis (EDX)
compositional bulk analysis in SEM and TEM
In combination with SEM and TEM. Local analysis and elemental distribution (SEM) with spatial resolution from (sub)mm (SEM) to a few nm (TEM).
Electron Energy Loss Spectroscopy (EELS)
compositional analysis and chemistry in TEM
Only in TEM. EELS can provide info about, e.g., composition and chemistry, and absolute thickness of a thin electron transparent TEM specimen.
Electron BackScatter Diffraction (EBSD)
compositional and crystallographic analysis on very thin films in SEM
When growing crystalline films, analysis can be done from a thickness of about 5 nm. Lateral resolution size as small a a few tens of nanometers. Sometimes in combination with EDX
probing optical and electronic properties in SEM, then correlate with composition and chemistry
CL in an SEM or scanning TEM (STEM) is a tool to characterise the optical and electronic properties of materials, then correlate them with morphology, microstructure, composition, and chemistry at the micron and sub-nm scale.
Matrix-Assisted Laser Desorption Ionization (MALDI) and ElectroSpray Ionization mass spectrometry (ESI)
analysis of bio– and large organic molecules
A soft ionization technique used in mass spectrometry, allowing the analysis of biomolecules and large organic molecules, which tend to be fragile and fragment when ionized by more conventional ionization methods.
Nanoparticle Tracking Analysis (NTA)
measurement of nanoparticle size and concentration; Visualization and analysis of Brownian motion tracks to determine particle size and concentration
Microscale Thermophoresis (MST)
measurement of binding constants in (bio)molecular interactions; Fast analysis of intermolecular interactions (KD’s) using microliter sample volumes
Circular Dichroism (CD) spectroscopy
measurement of chirality and protein secondary structure
xps, SEM: EDX
TEM: EDX, EELS, CL
SEM: EDX, CL, EBSD
Henk van Wolferen
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