Dr. Kaloian Koynov
Kaloian Koynov studied physics at the Sofia University and received his diploma in 1993. In 1997 he received his PhD from the same university for a work on cascaded nonlinear optical processes and their applications for all-optical switching in the group of Solomon Saltiel. Then he spent a postdoctoral year in the Institute for Fundamental Electronics, University Paris Sud, France, studying grating couplers into semiconductor waveguides. In 2000 he joined the department of Wolfgang Knoll at the MPI for Polymer Research as a postdoc and EU Marie Curie Fellow. Here, he worked with Christoph Bubeck on the nonlinear optical properties of thin films of conjugated polymers.
Since 2006 he is a group leader in the department of Hans-Jürgen Butt at the MPIP, where he leads the Fluorescence Correlation Spectroscopy group.
In addition, he is in charge of the service laboratory “Mechanic / Dielectric Properties” that provides numerous possibilities for characterization of macromolecular materials.
Research Interests
We develop and apply fluorescence correlation spectroscopy (FCS)-based approaches to address a broad range of questions in polymer, colloid and interface science.
On the one hand, we use FCS to measure the hydrodynamic radius, molecular brightness, and local concentration of fluorescent small molecules, macromolecules (polymers, copolymers, proteins, or DNA) and colloids. These measurements allow us to investigate conformational changes, mutual interactions, and aggregation processes. Such studies are particularly valuable for the characterization of drug nanocarriers in biological fluids, including blood plasma and whole blood.
On the other hand, by monitoring the mobility of fluorescent tracers of known size, we obtain information about the nano-rheological properties of their surrounding environment, ranging from polymer gels and bilayer membranes to fluid–fluid interfaces. These studies are complemented by classical rheology and investigations of the thermo-mechanical properties of polymer materials.
In addition to FCS, we develop complementary optical and fluorescence-based methods to investigate dynamic interfacial phenomena, including contact-line dynamics of sliding drops, interfacial pH variations, and slide electrification.