Laboratory of Experimental Chemical Physics
Chemical physics is a scientific discipline which utilizes physical methods to gain insight into the nature of molecules. This encompasses the study of the simplest water-type (H2O) to macromolecules (polymers) and their complexes and systems (solutions, suspensions, gels, polymer melts). The chemical physics research area is very close to the concept of soft matter physics. This laboratory devotes itself mainly to polymers. While biological polymers (nucleic acids, proteins, polysaccharides) are an integral part of living organisms and have been on Earth for a long time, synthetic polymers saw the light of day at the beginning of the 20th century. Although the first synthetic polymer (bakelite) was publicly introduced in 1907, the concept of the polymer, defined as long chains of atoms held together by covalent bonds, emerged considerably later (1922, Hermann Staudinger, later Nobel Prize laureate). The real development of polymer chemistry and physics occurred much later in the 20th century (Nobel Prizes – chemists Giulio Natta and Karl Ziegler, 1963, physicists Paul Flory, 1974 and Pierre-Gilles de Gennes, 1991). Polymeric macromolecus demonstrate such properties and behaviour that bear no resemblance to small “classical” molecules. Although research studies of synthetic and biological polymers were carried out either in parallel or independently, it turned out that these polymers exhibit many common phenomena and properties. The Laboratory focuses especially on ionic polymers (polyelectrolytes). The presence of charges in these molecules enables water solubility, ecological applications, and biological functions of biopolymers.
Macromolecules and especially their systems (solutions) represent a complex multiparticle problem for physicists. Multiparticle collective interactions cannot be measured directly, and therefore the information on the structure and dynamics of these systems gained experimentally in our Laboratory contribute to our knowledge about them. In addition to some often-quoted journal articles, we have published several chapters in monographs from renowned publishing houses (Clarendon Oxford, Marcel Dekker New York). In the recent past, we have succeeded in reorienting our long-term basic research findings also towards applications. We have created and patented a new mechanism for forming polymer nanoparticles of adjustable parameters out of ionic polymer chains – building units, based on physical bonds (not chemical reactions). Currently polymer nanoparticles find applications in many fields, with targeted transport of drugs and medical imaging probably being the most important.
The principal methods used in the Laboratory involve laser scattering (static, dynamic and electrophoretic), making use of several properties of laser radiation such as small wavelengths of approximately hundreds of nanometres, monochromaticity and coherence. Static scattering provides structural information in the range of approximately 20 nm to microns, dynamic scattering carried out in the form of photon correlation spectroscopy gains information on dynamic processes with relaxation times in the range of many orders (from the submicrosecond range to seconds) and indirect structural information from 1 nm. The electrophoretic scattering method is used for measuring the dynamics of molecules and nanoparticles in electric fields, and provides information on charges which are considerably different from so-called chemical charges (expected on the basis of chemical structure) due to various physical effects. These principal methods are supported by other analytical and preparative approaches.
The Institute of Experimental Physics SAS in Košice was established on January 1, 1969. Its research activities are devoted to condensed-matter physics, nuclear and subnuclear physics, space physics and biophysics. The Institute is based in 47 Watsonova St. Department of Low Temperature Physics is in P.J.Šafárik University area. Departments of Biophysics and Space Physics are located in 2-6 Bulharská St. with detached Space Physics laboratory on Lomnický štít.