PERIODO. MAGGIO - GIUGNO 2017

Il corso sarà tenuto dal prof. Valter Maurino del Dipartimento di Chimica dell'Università degli studi di Torino

Size distributions of nanoparticles and colloids are of paramount importance in defining their functional properties (e.g. self assembling, optical properties of films) and consequently their performances in several application fields. Therefore, the availability of quick, reliable and traceable methods for size distribution measurement is of paramount importance. This course will deal with the determination of the size distributions of ensemble of nanoparticles, colloids and macromolecules with methods that do not involve microscopic techniques.
Analytical methods used in particle characterization can be divided into ensemble and non-ensemble methods according to whether one detects signals or gathers information from particles of different properties or particles of the same property in the sample during each measurement. The advantages of ensemble methods, such as fast and non-intrusive measurement, are just the deficiencies of non-ensemble methods, namely time consuming analysis and sample destruction. In an ensemble method, since the signal is detected from particles having different properties, an information retrieval process that often involves modeling has to be used to convert the signal into a result. Two common ensemble methods used in particle size determination are photon correlation spectroscopy and laser diffraction.
After an overview of ensemble methods, the principles and applications of the following characterization techniques will be described:
1) Chromatographic Methods
Size Exclusion Chromatography
Hydrodynamic Chromatography
Field Flow Fractionation
2) Electrozone sensing methods
3) Laser Diffraction
4) Static and Dynamic light scattering
5) Electrophoretic light scattering and zeta potential measurement