| 1. |
- Bukartyk, Marta М., et al.
(författare)
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Preparation and research of properties of combined alginate/gelatin hydrogels
- 2022
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Ingår i: Journal of Chemistry and Technologies. - Ukraine : Oles Honchar Dnipropetrovsk National University. - 2663-2934 .- 2663-2942. ; 30:1, s. 11-20
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Tidskriftsartikel (refereegranskat)abstract
- The work presents the studies on the synthesis of hydrogel material based on the natural biopolymers (sodium alginate and gelatin) for medical applications. Sodium alginate and gelatin are biocompatible, non-toxic, biodegradable polymers and renewable raw materials. Combined alginate gelatin hydrogels are formed due to the formation of a hydrogel network by simultaneous cross-linking of calcium ions of sodium alginate macromolecules, gelatin, and macro-chains of rarely cross-linked polyacrylic acid. The optimal synthesis conditions (reagent concentrations, the molar ratio of calcium ions to the number of carboxyl groups Ca2+/COOH-) of the combined hydrogels with satisfactory physicochemical and mechanical properties are determined. The dependences of the mechanical properties of alginate-gelatin hydrogels on the degree of swelling indicate a wide range of their satisfactory performance characteristics. The studies on sorption and release of analgesics (lidocaine and novocaine) show long-term release of drugs and allow predicting the possibility of their prolonged delivery. In vitro cytotoxicity analysis proved the absence of toxic effect on living cells. The results suggest that the obtained combined alginate-gelatin hydrogels are a promising material for producing hydrogel dressings for wound care.
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| 2. |
- Shtepliuka, I., et al.
(författare)
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Microstructure and luminescence dynamics of ZnCdO films with high Cd content deposited on different substrates by DC magnetron sputtering method
- 2013
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Ingår i: Applied Surface Science. - : Elsevier. - 0169-4332 .- 1873-5584. ; 276, s. 550-557
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Tidskriftsartikel (refereegranskat)abstract
- Investigation of Cd behavior in the ZnCdO alloys, where Cd content exceeds the solubility limit, is of importance due to possible impurity segregation and second phases' formation in this material. We have studied the Cd behavior in the Zn1-xCdxO films deposited by dc magnetron sputtering on different substrates: c-plane Al2O3, bare Si (1 0 0) and Au (45 nm)/Si (1 0 0). It is revealed that Cd content of 10 at. % in the target results in average 6-8 at. % of Cd in the films, depending on the substrate type. Structural analysis based on X-ray diffraction revealed the absence of Cd-related secondary phases. Time-resolved photoluminescence (TRPL) and high-resolution energy dispersive X-ray analysis (EDX) help to understand the recombination dynamics of spontaneous emission and to establish correlations between cadmium content and radiative lifetime. We have revealed that the internal quantum efficiency is influenced by the Cd content and defect concentration. It is suggested that increasing of the cadmium content results in the reduction of nonradiative recombination centers originating from point defects.
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| 3. |
- Khomyak, V. V., et al.
(författare)
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Properties of p-n-junctions formed by a laser irradiation of a surface of n-Cd1-xZnx Te single crystal
- 2015
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Ingår i: Semiconductor Science and Technology. - : IOP Publishing: Hybrid Open Access. - 0268-1242 .- 1361-6641. ; 30:3
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Tidskriftsartikel (refereegranskat)abstract
- Photosensitive barrier structures were fabricated by high-power pulsed laser irradiation of a freshly-cleaved surface of n-type bulk Cd1-xZnxTe substrates. Their electrical properties were investigated and discussed. Dominant carrier mechanisms at a forward and a reverse bias in terms of a recombination and tunnel-recombination model were analyzed. At the illumination reaching 100 mW.cm(-2), these surface-barrier p-Cd1-xZnxTe/n-Cd1-xZnxTe structures were possessed by the following photoelectric parameters: open-circuit voltage V-oc = 0.61 V, short-circuit current I-sc = 0.21 mA and fill factor FF = 0.49, respectively.
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| 4. |
- Shtepliuk, I, et al.
(författare)
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Electrical properties of n-Zn0.94Cd0.06O/p-SiC heterostructures
- 2013
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Ingår i: Solid-State Electronics. - : Elsevier BV. - 0038-1101 .- 1879-2405. ; 81, s. 72-77
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Tidskriftsartikel (refereegranskat)abstract
- We report the low-temperature (250 °C) fabrication of n-ZnCdO/p-SiC heterostructures by direct current magnetron sputtering (DC MS) technique. As-grown heterostructures exhibit diode characteristics: current–voltage measurements showed a typical rectifying characteristic of a p–n junction and the presence of series resistance. It is found that the turn-on voltage of heterostructures depends on the acceptor concentration in p-SiC. Via Cd doping of ZnO the energy barrier for holes can be lowered, which promotes the hole injection from the p-type layer to the n-type layer as well as favors the radiative recombination in the n-ZnCdO layer.
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| 5. |
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| 6. |
- Khomyak, V., et al.
(författare)
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Band-gap engineering of ZnO1-xSx films grown by rf magnetron sputtering of ZnS target
- 2015
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Ingår i: Vacuum. - : PERGAMON-ELSEVIER SCIENCE LTD. - 0042-207X .- 1879-2715. ; 121, s. 120-124
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Tidskriftsartikel (refereegranskat)abstract
- Structural and optical properties of ZnO1-xSx (0 less than= x less than= 1.0) thin films grown onto sapphire substrates (c-Al2O3) at 300 degrees C by radio frequency (rf) magnetron sputtering of ZnS ceramic target are studied. A possibility of purposeful controlling sulfur content and, as consequence, ZnO1-xSx band gap energy via changing the ratio of the partial pressures of argon and oxygen are revealed. Linear dependence of ZnO lattice parameter c on S content suggests that structural properties of single-phase ternary alloys in the composition range between ZnO and ZnS obey Vegards law. The mechanisms of influence of gas mixing ratio on film growth and band gap energy are discussed. Cu(In,Ga)Se-2 (CIGS)-based heterojunction solar cells with ZnO1-xSx buffer layers were fabricated by one-cycle magnetron sputtering procedure. Electrical characteristics of Cd-free devices are comparable to those of CdS-containing photovoltaic heterostructures, thereby indicating prospects of using ZnO1-xSx layers for fabrication of CIGS solar cells. (C) 2015 Elsevier Ltd. All rights reserved.
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| 7. |
- Shtepliuk, I., et al.
(författare)
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Valence band structure and optical properties of ZnO1-xSx ternary alloys
- 2015
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Ingår i: Journal of Alloys and Compounds. - : ELSEVIER SCIENCE SA. - 0925-8388 .- 1873-4669. ; 649, s. 878-884
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Tidskriftsartikel (refereegranskat)abstract
- The k.p method and the effective mass theory are applied to compute valence-band electronic structure and optical properties of ZnO1-xSx ternary alloys under biaxial strain. A significant modification of the band structure with increasing sulfur content is revealed. Features of wave-functions and matrix elements in the transverse electrical (TE) and transverse magnetic (TM) regimes for three valence subbands are studied and discussed. The results of calculations of interband transition energy and spontaneous emission spectra are in agreement with experimental data for ZnO1-xSx films grown by radio-frequency magnetron sputtering technique. (C) 2015 Elsevier B.V. All rights reserved.
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