Effects of Non-Equilibrium Plasma Processing on Solutions of D-, L-Isomers
Authors:   Faculty of RECS, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, Chernyak Valeriy , Shulga Sergeiy ,   Institute of Hydromechanics NAS of Ukraine, Kyiv, Ukraine, Iukhymenko Vitalii ,   Institute of Hydromechanics NAS of Ukraine, Kyiv, Ukraine, Tretiakov Daniil ,   Faculty of RECS, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, Trachevskiy Volodymyr ,   GV. Kurdyumov Institute for Metal Physics of the NAS of Ukraine, Kyiv, Ukraine, Kolomys Oleksandr ,   V. Lashraryov Institute of semiconductor physics of the NAS of Ukraine, Kyiv, Ukraine, Strelchuk Victor ,   V. Lashraryov Institute of semiconductor physics of the NAS of Ukraine, Kyiv, Ukraine, Kyslyi Volodymyr ,   V. Lashraryov Institute of semiconductor physics of the NAS of Ukraine, Kyiv, Ukraine, Iukhymenko Kostiantyn ,   Faculty of RECS, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, Tsymbaliuk Olexander ,   Faculty of RECS, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, Nedovesov Sergeiy ,   Faculty of RECS, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine, Diamant Victor ,   V.I. Vernadsky Institute of General and Inorganic Chemistry NAS of Ukraine, Kyiv, Ukraine, Voskobijnyk Volodymyr ,   Institute of Hydromechanics NAS of Ukraine, Kyiv, Ukraine
Published: January 2025

This work is devoted to the study of the possibility of violating one of the basic provisions of chemical thermodynamics in a strongly non-equilibrium plasma-chemical system. Particular attention is paid to the fact that “living” biomaterials are characterized by both the arrangement of chiral components and the course of chemical transformations in organic chemistry under quasi-equilibrium conditions. In view of this, the features of the plasma effect on aqueous solutions of D fructose, D glucose, D tartaric acid and ethanol solutions of D fructose and L proline are considered, which is associated with the introduction of energy by the plasma flow sufficient for significant destruction of organic molecules. The non-equilibrium of the plasma-chemical system provides not only a significant energy-mass exchange with the environment, but also the absence of equivalence in the directions of motion of reagent particles, which is realized by the gas dynamics of the rotating gas flow in the system.

Determination of such physicochemical properties of solutions as optical activity of solutions, adsorption spectra in UV and IR ranges, Raman scattering spectra and NMR spectroscopy on protons and 13C nuclei was carried out before and after their plasma activation. Optical activity was determined using a laser modulation polarimeter. Transmittance in the UV range -200 - 400 nm was determined using a spectrometer with a CCD detector (Solar TII). Transmittance in the IR range (500 - 4000 cm-1) was determined using a Fourier spectrometer. Raman spectra (70 - 3600 cm-1) were obtained in quasibackscattering geometry using a Horiba Jobin-Yvon T64000 triple spectrometer with an integrated micro-Raman scattering setup - an Olympus BX-41 microscope and a Peltier-cooled CCD detector.

It is shown that the spectral characteristics of the studied solutions of optically active isomers change significantly after plasma treatment: the nature of the change is influenced by both the direction of rotation of the gas flow in the system and the nature of the optical activity of the dissolved initial isomer. The change in the throughput of the solutions in the UV range indicates a significant destruction of the initial hydrocarbon reagent. Spectroscopic studies (in the UV and IR ranges, NMR-13C) of L-proline in C2H5OH solutions activated by the plasma of an immersed rotating sliding discharge, Raman scattering of solid-phase precipitates formed after solvent evaporation revealed a significant influence of the direction of rotation of the gas flow in the plasma-liquid system on the kinetics of physicochemical processes in it. The optical activity of solutions during the first hours after treatment changes chaotically, but its stabilization time does not exceed 1 day for solutions of glucose, fructose, proline and tartaric acid. The main conclusion from the study of solutions after plasma activation in an open non-equilibrium plasma-liquid system, which has significant parameter gradients and does not have a uniform probability in the directions of forced rotation of reagent particles using solutions of chemically pure, optically active reagents, is that plasma activation enables both destructive processes and a significant change in the optical activity of solutions. The change in the optical activity of solutions of polar chiral substances (glucose and fructose) after plasma activation noticeably depends on the direction of forced rotation of reagent particles. The influence of the direction of forced rotation of reagent particles on the change in the optical activity of solutions of non-polar chiral reagents (proline and tartaric acid) was practically absent.