Prof. Wolfgang Peukert, 12 Jul 2018
July 12 (Thu) 2018, 14:00-16:00
Kyoto University Katsura Campus A4-115
Multidimensional characterization of colloidal nanoparticles
Prof. Wolfgang Peukert, University Erlangen-Nuremberg, Germany
An important worldwide trend in particle technology is the requirement to understand systems of ever increasing complexity. Available techniques for particle characterization are predominantly focused on size characterization. Even simultaneous size and shape characterization is still an unresolved major challenge. Beyond size, also shape, particle surface and the particle’s inner structure come into focus. These structural features are closely related to biological, chemical, electronic, mechanical and optical properties of the particles opening vast opportunities in many fields of application including nanoelectronics, photonics, energy conversion and storage, and the life sciences. The grand challenge is to design particle systems with specific and well understood functionalities and to transfer these systems to real world applications. Efficient and economical production of these particle systems inevitably requires the ability to characterize systems that display distributions in all their properties.
Novel approaches are presented which give access to multidimensional information beyond size. The only known technique which is capable of multidimensional particle characterization is analytical ultracentrifugation equipped with novel inline multiwavelength absorption optics (MWL-AUC). Size, shape, and spectral information are accessible simultaneously, thus largely expanding the capabilities of multidimensional particle analysis over a broad particle size range from below a nanometer to several microns. MWL-AUC offers great advantages for studying systems in solution phase, where dynamic interactions can be measured with high statistical confidence to provide unrivaled resolution for multidimensional particle size, shape as well as hydrodynamic and spectral property distributions. For instance, we show how to measure full 2D length and diameter distributions of plasmonic gold nanorods in one single experiment. Particle surfaces are characterized by a number of complementary techniques including MWL-AUC, SAXS/SANS and, in particular, by means of nonlinear spectroscopy (second harmonic generation and sum frequency generation) allowing fast optical access to particle surface properties in liquids including charge, adsorbed molecules and ligand exchange.
* JGP_Seminar_Prof_Wolfgang_Peukert.pdf (107 KB) hosted on Box: app.box.com/s/55z1xlieahx0ulpn6ujrhrx39t7i1vl5