Research

In our group, we perform experimental research in the field of physical and colloid chemistry. The most often used measurement techniques include light scattering (SLS and DLS), microscopy (AFM, TEM and SEM), spectroscopy (UV-Vis and FT-IR), rheology and electrophoresis. The main research directions are as follows.

Development of bionanocomposites of antioxidant activity

Antioxidant enzymes have been considered as the most efficient and selective catalysts in decomposition of reactive oxygen species. However, their sensitivity to the environmental conditions limits their supplementation. Immobilization of enzymes or enzyme mimicking compounds is a promising research direction towards the development of novel biocatalysts with the same activity, but less sensitivity than the native enzymes. However, several fundamental questions concerning their large scale preparation, colloidal and functional stability have to be answered. Our group aims for the design of bionanocomposite dispersions consist of native (e.g., superoxide dismutase, catalase and horseradish peroxidase) or artificial (mimicking metal complexes and metal-based nanoparticles) enzymes, nanoparticulate (e.g., layered double hydroxide, titania and polymeric latex) supports and stabilizing biopolymers (e.g., heparin, protamine and serum albumin).

References

Colloids Surf. B 216, 112531 (2022)

Scientific Reports 11, 4321 (2021)

Journal of Molecular Liquids 309, 113066 (2020)

Journal of Colloid and Interface Science 543, 174 (2019)

Journal of Physical Chemistry C 122, 21 (2018)

Ion specific effects on the stability of particle dispersions

The influence of ions of various compositions and valences on the charging and aggregation processes in dispersions of nano or colloidal particles has been in the focus of numerous researchers for a long time. These phenomena can be described by the Hofmeister series of ions and the Schulze-Hardy rule for mono and multivalent electrolytes, respectively. However, due to the relevance of this issue in biomedical (e.g., drug delivery in biofluids), environmental (e.g., wastewater treatment) and other industrial (e.g., papermaking) applications of particles, this topic attracts widespread contemporary interest. We study the destabilization power of simple inorganic anions and cations (e.g., Cl^-, CO₃^2-, PO₄^3-, Na⁺, Ca²⁺ and La³⁺) in dispersions of nanoparticles and their composite materials. A novel direction in this research is the application of pure of hydrated ionic liquids as dispersion medium.

References

J. Phys. Chem. Lett. 13, 11850 (2022)

Langmuir 37, 11869 (2021)

Physical Chemistry Chemical Physics 22, 24764 (2020)

Journal of Physical Chemistry C 123, 12966 (2019)

Colloids and Interfaces 2, 32 (2018)

Formulation of colloidal particles with polyelectrolytes

Polyelectrolytes tend to adsorb strongly on oppositely charged particle surfaces and such adsorption changes the charging properties and the interparticle force profiles. Stable and unstable particle dispersions can be designed by varying the composition and the dose of the polyelectrolytes. Many manufacturing processes rely on these phenomena in the food, cosmetic or paint industry, where colloidal stability is a key issue in the development of good quality consumer products. In our group, the interaction of natural (e.g., polysaccharides) and synthetic (e.g., PAMAM dendrimers) polyelectrolytes with various particles is being investigated from the perspective of surface charge properties and aggregation processes. The main goal is to be able to predict colloidal stability of dispersions on the basis of the composition and physical properties of the polyelectrolytes and particles.

References

J. Mater. Chem. B 10, 2523 (2022)

Dalton Transactions 50, 2426 (2021)

Soft Matter 16, 10518 (2020)

Langmuir 35, 4986 (2019)

Nanomaterials 8, 986 (2018)