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Interface interactions and optical properties of novel photonic nanocomposites consisting of porous glasses doped with organic luminophore molecules

Antropova T.V., Baran J., Gavrilko T., Gnatyuk I., Morawska-Kowal T., Melnik V., Puchkovska G., Vorobjev V.

Optica Applicata

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2005

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Vol. 35, nr 4

725-733

EN

Absorption and luminescence spectra of nanocomposites consisting of photonic molecules rhodamine 6G, trishydroxyquinoline aluminum (Alq3) complex and benzophenone adsorbed on soda-borosilicate porous glasses from ethanol and dichloromethane (DCM) solutions are investigated. The effect of sorption interactions at the interface between the glass pore surface and the organic media on luminescent and optical characteristics of the nanocomposites was investigated by NIR spectroscopy. It was shown that spectral changes observed in the absorption and emission spectra of the luminophores in the porous glasses are determined by the balance between physical interaction of the organic molecule with different adsorption centers on the pore walls and solvation effect.

2

Structure and Lattice Dynamics of NH4IO3 . 2HIO3 Crystal as Derived from IR, Raman and 127 I NQR Data

Barabash A., Baran J., Gavrilko T., Puchkovskaya G., Ratajczak H., Tarnavski Y.

Polish Journal of Chemistry

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2003

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Vol. 77 / nr 11

1547-1559

EN

The IR absorption and Raman spectra of NH4IO3_2HIO3 crystal (AIH) were reinvestigated in a wide temperature range (13-300 K), including the phase transition temperature Tc = 213 K. The pressure dependences of the quadrupole coupling constant e2Qqzz and asymmetry parameter of electric field gradient tensor (EFGT) were obtained from the analysis of 127I nuclear quadrupole resonance (NQR) spectra at 77 K. It was shown that the phase transition of the crystal can be described as an isostructural phase transition with ordering of protons in bifurcated hydrogen bonds and duplication of the unit cell.

3

Application of NIR spectroscopic method to the study of porous glasses filled with liquid crystals

Gavrilko T., Gnatyuk I., Puchkovska G., Baran J., Marchewka M., Morawska-Kowal T.

Optica Applicata

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2003

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Vol. 33, nr 1

23-32

EN

The paper focuses on NIR spectroscopic studies of the structure of surface active centers and interface interactions in novel nanocomposition materials built of nanoporous glasses (PG) and n-alkylcyanobiphenyl (nCB) liquid crystals (LC). NIR (12000–4000 cm–1) spectra of bare PG with pore size ranging from 2 to 10 nm and those loaded with nCB (n = 2, 4, 5, 8) were investigated at room temperature for two types of PG of variable surface activity preheated to 200 °C (type I) and 600 °C (type II). The number of surface active centers for the two types of PG has been evaluated as a function of pore diameter, and the relative number of the LC molecules directly bounded to the pore active centers was estimated.

4

Effect of confinement to porous glass on structure and optical properties of alkylcyanobiphenyls.

Bezrodnaya T., Gavrilko T., Gnatyuk I., Yaroshchuk O., Puchkovskaya G., Baran J., Ratajczak H., Kukielski J.I.

Optica Applicata

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2000

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Vol. 30, nr 4

585-590

EN

The 4-n-alkyl-4'-cyanobiphenyls (nCB, n is the number of carbon atoms in alkyl radical n=5, 8) confined to porous glasses with four different mean pore sizes (2, 4, 54 and 90 nm) have been studied. Using FT MIR and NIR spectroscopy methods we have investigated the interaction of nC8 molecules with the pore surface. It has been shown that the interaction is accompanied by the formation of hydrogen bonds between the SiOH group on the glass pore surface and the cyano-group of the nCB monomer. This is demonstrated by the change in the position and shape of CN stretching and Q(C identical to N)+Q(C=C) combination bands in the vibrational spectra of confined nCB depending on pore size and the length of the alkyl tail. To the contrary, in the case of benzophenone confined to PG, weak pi ...OH-Si hydrogen bonds are formed.