Liudmila Filippovich

Broad band thermostable polarizing film based on poly (vinyl alcohol), a quinoline derivative and ZnO nanoparticles

In the present study, for the first time on the basis of polyvinyl alcohol (PVA), dichroic dyes: (sodium 4-[(4E)-4-[(2E)-2-(2-chloro-3-{(E)-2-[1-(4-sulfonatobutyl)quinolinium-4-yl]ethenyl}-2,3-dihydro-1H-inden-1-ylidene)ethylidene]quinolin-1(4H)-yl]butane-1-sulfonate) (I), 6-amino-4-hydroxy-3-((4-(phenyldiazenyl)phenyl)diazenyl)naphthalene-2-sulfonic acid (II), and Chicago Sky Blue (III) broad band thermostable polarizing PVA-films were created. The obtained polarizing PVA-films had polarizing efficiencies (PEs) in the range of 97–99% in UV-Vis (300–695 nm) and PEs of 90–96% in the near IR (819–855 nm) regions of the spectrum. The photostability of the films could be improved by ZnO nanoparticles (average length ∼ 1 μm and diameter ∼ 85 nm) incorporated in a polymer matrix. Apparently, ZnO NPs act as a stabilizer in the photochemical process of dye degradation. During the study, it was established that oriented broad band PVA-films are a phenomenon of the anisotropy of thermal conductivity (λ‖/λ⊥). This is very important for the existence of thermostable polarizing PVA-films. It was also found that in the films the thermal conductivity in the direction of orientation (λ‖) was higher than in a direction perpendicular to the orientation (λ⊥).

Anisotropy (optical, electrical and thermal conductivity) in thin polarizing films for UV/Vis regions of spectrum: Experimental and theoretical investigations

In the present work, the quantum theoretical calculations of the molecular structures of the three newly synthesized azomethine dyes: have been predicted using Density Functional Theory (DFT) in solvent dimethylformamide (DMF). The geometries of the azomethine dyes were optimized using the PBE1PBE/6-31+G level of the theory. In addition, the electronic spectra of these compounds in solvent DMF were carried out using the TDPBE1PBE, TDPBEPBE, TDB3LYP methods with 6-31G, 6-31+G, 6-31+G*, 6-31++G* basis sets. After quantum-chemical calculations three new azomethine dyes for optoelectronic applications were synthesized. Based on polyvinyl alcohol (PVA) and the new synthesized azomethine dyes polarizing films for UV/Vis regions of the spectrum were developed. The main optical parameters of polarizing PVA-films (Transmittance and Polarization Efficiency) have been measured and discussed. Anisotropy of electrical and thermal conductivity of the PVA-films has been investigated.

IR-polarizing film containing a new quinoline dye and Fe3O4 nanoparticles: optical and thermophysical investigations

In the present work, the structure and some molecular properties of a new substance, monosodium mono(4-(2-(2-(2-chloro-1-(2-(1-(4-sulfonatobutyl)-3,4-dihydroquinolin-2(1H)-ylidene)ethyliden)-1H-inden-3-yl)vinyl)-3,4-dihydroquinolin-1(2H)-yl)butane-1-sulfonate (M), with a strong maximum absorption in the near IR region (λmax = 764 nm) of the spectrum, was modeled using the Density Functional Theory method (DFT/B3LYP/6-311++G*) and then synthesized. The calculated electronic absorption spectrum of M in dimethylformamide (DMF) by TDB3LYP/6-311++G* method and the experimental spectra of M in DMF and in aqueous medium are presented. The charge delocalization of M has been performed with the help of natural bond orbital (NBO) analysis. The UV, IR, and 1H NMR spectra of M are presented. On the basis of poly(vinyl alcohol) (PVA), a thermostable polarizer film was developed incorporating the new synthesized dye M and magnetite (Fe3O4) nanoparticles (NPs) absorbing in the near IR region of the spectrum (λmax = 750–812 nm) and with polarization efficiency (PE = 95%) in the absorption maximum. The main spectral polarization parameters (transmittance and optical density) of the stretched colored PVA films with M and M + Fe3O4 NPs were measured and discussed. Oriented colored PVA films having the phenomenon of anisotropy of thermal conductivity (λ∥/λ⊥) were established. Thermal conductivity in the direction of orientation (λ∥) is higher than that in the direction of perpendicular orientation (λ⊥). The developed thermostable IR-polarizer film may be used in laser technologies, polarizing microscopes, circular polarizers, magnetometers, spectropolarimeters and electrical signal sensors.

Spectroscopic Studies (Geometry Optimization, E → Z Isomerization, UV/Vis, Excited States, FT-IR, HOMO-LUMO, FMO, MEP, NBO, Polarization) and Anisotropy of Thermal and Electrical Conductivity of New Azomethine Dyes in Stretched Polymer Matrix

AbstractIn the present work, first time the molecular structures of three newly synthesized azomethine dyes: (1Z)-N-benzylidene-4-((E)-1-(oxim)ethyl)benzenamine (AAFOX-1), 4-((1Z)-(4-((E)-1-(oxim)ethyl)phenylimino)methyl)phenol (AAFOX-7), (Z)-1-(4-((Z)-(4-methoxybenzylidene)amino)phenyl)ethanone oxime (AAFOX-8) have been investigated using Density Functional Theory (DFT) in dimethylformamide (DMF). The electronic spectra of azomethine dyes in a DMF solvent was carried out by TD-DFT method. After quantum-chemical calculations three new azomethine dyes for optoelectronic applications were synthesized. FT-IR spectra of the title compounds are recorded and discussed. The computed absorption spectral data of the azomethine dyes are in good agreement with the experimental data, thus allowing an assignment of the UV spectra. The molecular HOMO-LUMO, excitation energies and oscillator strengths for E and Z isomers of the dyes have also been calculated and presented. Optical Properties of the PVA-films containing new substances have been also investigated. Polarizing Efficiency (PE) of obtained PVA-film is 70–80 % at Stretching Degree (Rs) 3.5. First time anisotropy of thermal and electrical conductivity of PVA-films containing E and Z isomers of the dyes was also measured and discussed. It is new result for physical chemistry of organic dyes. Graphical AbstractWe studied anisotropy of thermal and electrical conductivity of new azomethine dyes in stretched polymer matrix and electronic properties of new azomethines have been also investigated using Density Functional Theory (DFT) in dimethylformamide (DMF).