Hydrophilic polyelectrolyte microspheres as a template for poly(3,4-ethylenedioxythiophene) synthesis.

Conducting polymer polyelectrolyte microspheres are typically composed of a cationic conducting polymer and an anionic polymer. The polymer chains inside these microspheres are physically or chemically cross-linked, creating a network that enables high water retention. Poly(3,4-ethylenedioxythiophene) (PEDOT) being an electrically conductive polymer exhibits a high conductivity and has great biotechnological applications. The unique combination of properties of PEDOT containing polyelectrolyte microspheres makes them widely investigated materials for electroresponsive cells, tissue engineering, and bio-sensors. The demand to produce PEDOT with varied properties depending the specific application requires the understanding of the basic principles of template formation. In the present work, we studied the inverse suspension polymerization of p-styrenesulfonic acid in the presence of a cross-linking agent as a synthetic way for the formation of porous polyelectrolyte microspheres. We traced how the nature of the emulsifier affected both the structure of the surface layer of the microspheres and the degree of their cross-linking. The porous structure of polyelectrolyte microspheres obtained is found to promote the polymerization of EDOT in their presence throughout the entire microsphere volume. The structural characteristics of the polyelectrolyte/PEDOT complexes in relation to their electrochemical properties have been studied.

Influence of the Nature and Structure of Polyelectrolyte Cryogels on the Polymerization of (3,4-Ethylenedioxythiophene) and Spectroscopic Characterization of the Composites.

Conductive hydrogels are polymeric materials that are promising for bioelectronic applications. In the present study, a complex based on sulfonic cryogels and poly(3,4-ethylenedioxythiophene) (PEDOT) was investigated as an example of a conductive hydrogel. Preparation of polyacrylate cryogels of various morphologies was carried out by cryotropic gelation of 3-sulfopropyl methacrylate and sulfobetaine methacrylate in the presence of functional comonomers (2-hydroxyethyl methacrylate and vinyl acetate). Polymerization of 3,4-ethylenedioxythiophene in the presence of several of the above cryogels occurred throughout the entire volume of each polyelectrolyte cryogel because of its porous structure. Structural features of cryogel@PEDOT complexes in relation to their electrochemical properties were investigated. It was shown that poly(3,4-ethylenedioxythiophene) of a linear conformation was formed in the presence of a cryogel based on sulfobetaine methacrylate, while minimum values of charge-transfer resistance were observed in those complexes, and electrochemical properties of the complexes did not depend on diffusion processes.

Short-term Variability of Macro- and Trace Elements in Elymus Repens L. and Urtica Dioica L.

BACKGROUND: The main aim of the research was to study short-term changes in the concentrations of elements in two widely distributed plant species, couch grass and nettle and in the rhizosphere soil of the plants. METHODS: The sampling of plants and soil was carried out on three dates: 3, 10, and 25 May 2021. On each day of sampling, the plants and soil were collected three times: at 9:00, 14:00, and 19:00. The ICP-OES and ICP-MS analytical techniques were used for determination of elements in the plant and soil samples. The Raman spectroscopy was applied to study variations in the organic compounds. RESULTS: The concentrations of both macro-nutrients and trace elements in plants varied greatly over daytime on all dates of sampling. The differences between concentrations of many elements in the plants collected at different times during a day were statistically significant. There were also statistically significant differences between concentrations of some elements (Na, Mg, P, K, Fe, Ba) in the plants collected on different dates. The relative intensity of diffuse luminescence of the rhizosphere soil of couch grass and nettle was different during daytime and also differed between the soils taken from roots of the two plant species, especially in the beginning of May. CONCLUSIONS: The experimental data indicates that the daily variations of the element concentrations in plants might be a result of multiple effects of various factors. The differences in the daily element variations in the couch grass and nettle growing in the same site and collected simultaneously might be due to the fact that these plants belong to different clades. The diurnal fluctuations (that also include regular changes in the element concentrations in plants) can be different for monocotyledons (couch grass) and dicotyledons (nettle). New experimental findings on short-term variations in the concentrations of macro-nutrients and trace elements can help to gain a new insight into accumulation of the elements in different plant species and also be useful in agricultural practice.