The measurement of the viscosity of liquid systems (pure liquids or their mixtures) and structured fluids such as suspensions, emulsions and polymeric solutions is performed with rotational rheometers. The sample put between two measuring elements is put in motion by applying a torque and the corresponding angular speed is measured (or vice versa). Such macroscopic measurable variables are then converted in local properties, shear stress and shear rates, whose ratio gives the shear viscosity. By changing the torques (or angular speeds) applied the dependence of viscosity on shear stress (or shear rate) can be found (flow curves).
In SEM a beam is scanned over a sample surface while a signal from secondary or back-scattered electrons is recorded. SEM is used to image an area of the sample with nanometric resolution, and also to measure its composition, crystallographic phase distribution and local texture.
In TEM/Scanning TEM (STEM) high energy electrons incident on ultra-thin samples, allow imaging, diffraction, electron energy loss spectroscopy and chemical analysis of solid materials with a spatial resolution on the order of 1-2 Å. Samples must have a thickness of a few tens of nanometres and are prepared in sample preparation laboratory.
SAXS is a non-destructive and versatile method to study the nanoscale structure of any type of material (solid, liquid, aerosols) ranging from new nanocomposites to biological macromolecules. Averaged particle sizes, shapes and distributions, porosity, degree of crystallinity and electron density maps with nanometer precision can be obtained.
The thermal analyses are the set of techniques in which a physical property of a substance is measured as a function of temperature (or time) while the sample is subjected to a controlled temperature program (heating, cooling, isotherm).
