Wyniki wyszukiwania - BazTech

1

Manufacturing and characterization of gellan gum – zinc oxide composites as potential biomaterials for wound treatment

Macyk Alicja, Kusibab Anna, Pamuła Elżbieta

Engineering of Biomaterials

|

2023

|

vol. 26, no. 168

2--8

EN

This study aimed to produce gellan gum-based hydrogels with the addition of zinc oxide as a potential dressing material. Hydrogels with ZnO concentrations of 0.01%, 0.02% and 0.04% were prepared, micrometric and nanometric ZnO particles were used, and a CaCl2 crosslinker was added to one part of the samples. All samples (14 types) produced by the freeze drying method were characterized with high swelling properties (>2000%), what is important to ensure the absorption of exudates from wounds. Samples with ZnO particles cross-linked with CaCl2 lost less mass after incubation in aqueous media and were characterized by better dimensional stability than those without crosslinking. The pH of the extracts of the samples containing ZnO particles was more neutral (pH 7.0-7.6) than that of the control gellan gum samples (pH of 5.5-6.1). The zinc release from cross-linked samples was twice as high for those containing nanometric particles than for micrometric particles (1.94 ± 0.04 mg/l and 0.93 ± 0.02, respectively). Relatively large amounts of released zinc species in the case of samples containing ZnO nanoparticles are promising in the context of the antibacterial properties and treatment of infected wounds. A lower amount of zinc released from samples with ZnO microparticles could be sufficient to prevent the development of the infection. Furthermore, both materials show satisfactory cytocompatibility with L929 fibroblasts, as shown by Alamar blue and live/dead viability tests, making them prospective candidates for wound healing

2

Materials based on chitosan enriched with zinc nanoparticles for potential applications on the skin

Kulka Karolina, Szmejkowska Andżelika, Sionkowska Alina, Wypij Magdalena, Golińska Patrycja

Engineering of Biomaterials

|

2022

|

vol. 25, no. 167

24--31

EN

Chitosan as a nontoxic, biodegradable, and biocompatible biopolymer with film-forming properties can also be modified to improve its parameters. Modification of polymer films by the addition of nanoparticles is an increasingly common solution due to the higher efficiency of products at the nanoscale compared to the macroscale. In this work, thin chitosan films enriched with biogenic zinc oxide nanoparticles (ZnONPs) from Fusarium solani IOR 825 were obtained by the solvent evaporation method. The influence of nanoadditive on the physicochemical, mechanical, and antimicrobial properties of the polymeric matrix was evaluated. Two different concentrations of ZnONPs were added to the chitosan solution. Spectrometric measurements, mechanical tests, microscopic imaging, and microbiological tests were performed for nanoparticlesmodified and control samples. Analysis revealed that ZnONPs influence the properties of chitosan films. FTIR spectroscopy showed changes that are the result of interactions between polymer matrix and the additive. Modified samples were characterized by increased values of Young’s modulus and tensile strength. SEM analysis combined with energy-dispersive X-ray spectrometry confirmed the presence of zinc in the modified films. The addition of nanoparticles slightly affected the surface morphology of the tested samples, and an increase in roughness was observed. Microbiological tests showed the biostatic activity of the films containing ZnONPs. The obtained films based on chitosan with the addition of ZnONPs can be considered easy-to-obtain biomaterials with potential use as cosmetic and biomedical products.

3

Effect of Weave Structures and Zinc Oxide Nanoparticles on the Ultraviolet Protection of Cotton Fabrics

Timothy R., Arul Pragasam A. J.

Fibres & Textiles in Eastern Europe

|

2018

|

Vol. 26, no. 1 (127)

113--119

EN

The protection provided by clothing against ultraviolet (UV) radiation has been the subject of considerable recent research. However, there is a lack of information concerned with the effect of weave structures and zinc oxide nanoparticles on these properties. A series of cotton fabrics differing in weave structure was produced and treated with zinc oxide nanoparticles. These fabrics were spectrophotometrically assessed and the UV protection factor calculated. It was found that while there was no significant difference in the Ultraviolet Protection Factor (UPF) in untreated samples, in samples treated with zinc oxide nanoparticles an increase was noticed in satin and granite weaves. There is no relationship between weave parameters and the UPF. Also between porosity and the UPF, no relationship was noticed. Thus the present study provides design guidelines for clothing manufacturers.

PL

Ochrona zapewniana przez odzież przed promieniowaniem ultrafioletowym (UV) była przedmiotem wielu badań. Brak jest jednak informacji dotyczących wpływu struktur splotów i nanocząstek tlenku cynku na te właściwości. Przedmiotem pracy było wytworzenie tkanin bawełnianych różniących się strukturą splotów, a następnie poddano te tkaniny obróbce nanocząstkami tlenku cynku. Tkaniny te zostały ocenione spektrofotometrycznie i obliczono współczynnik ochrony przed promieniowaniem UV. Stwierdzono, że chociaż nie było istotnej różnicy we współczynniku ochrony przed promieniowaniem ultrafioletowym (UPF) w nieobrabianych próbkach, w próbkach obrabianych nanocząsteczkami tlenku cynku zauważono wzrost w splocie satynowym i granitowym. Stwierdzono, że nie ma związku pomiędzy parametrami splotu a UPF. Również między porowatością a UPF nie zauważono żadnego związku. Przedstawione wyniki badań mogą być źródłem wytycznych projektowych dla producentów odzieży.

4

The photoluminescent layers based on ZnO nanoparticles as radiation converters in photovoltaic applications

Szczecińska N., Znajdek K., Sosna-Głębska A., Lewicki P., Czarnecki P., Kraska P., Bazdyga C., Wiosna-Sałyga G., Sibiński M.

Acta Innovations

|

2018

|

no. 29

16--26

EN

The mismatch between solar cell response and solar spectrum is one of the biggest challenges to achieve high efficiency in photovoltaic cells. There are a few different approaches to minimise this concern. One of them is the radiation conversion which may be due to three different processes, namely up-conversion, down conversion and down-shifting. In this paper the down-conversion process of zinc oxide nanoparticles (ZnO NPs) and layers with ZnO NPs in polymer (poly (methyl methacrylate)) (PMMA) matrix will be analysed. ZnO NPs are prone to act as down-converting or down-shifting agents, which absorb the UV radiation, which is not absorbed by the solar cell, and then re-emit light in the visible range, which is suited to the photovoltaic cell sensitivity. Herein, the photoluminescence and optical transmittance of ZnO NPs and layers based on ZnO NPs will be presented. These parameters have a large influence on the potential application of these layers in photovoltaic structures for increased efficiency. The conversion layers have to fulfil the following conditions: have good optical transmittance in the visible range and high luminescence efficiency in converting UV radiation into visible. The paper focuses on finding the balance between these parameters.

5

Hydrometallurgical treatment of non-sulfide zinc ore for precipitation of zinc oxide nanoparticles

Abdel-Aal E.-S. A., Rashad M. M., El-Shazly A. N., Ibrahim I. A., El-Shahat M. F.

Physicochemical Problems of Mineral Processing

|

2016

|

Vol. 52, iss. 2

729--737

EN

Acid leaching of Egyptian zinc ore from the Um Gheig area was carried out with sulfuric acid. This study determines the optimum conditions for dissolution of non-sulfide zinc ore. The optimum conditions are 25% -74m particle size, 45 °C temperature, 2 h leaching time, 1.1 stoichiometric molar ratio of H2SO4 to Zn, 1:3 solid/liquid ratio. The maximum filtration rate is 1.6 Mg Zn•m-2•day-1at pressure difference of 0.80 bar. The zinc recovery is about 90%. As the zinc ore contains zinc silicate, some additives were tested to enhance filtration and prevent formation of silica gel. To increase the added value of the product, zinc oxide was precipitated by a co-precipitation method in a nanosize powder with average particle size ~ 20 nm. Photocatalytic degradation of methylene blue dye under UV light using ZnO nanopowders produced at different conditions was investigated. Photocatalytic efficiency with methylene blue (MB) concentration was reduced as much as 85% in 240 min with the produced nanoparticles.

6

Investigation on room temperature photoluminescence of pure and aluminum doped zinc oxide nanoparticles

Srinivasan N., Kannan J. C.

Materials Science Poland

|

2015

|

Vol. 33, No. 1

205--212

EN

Pure and aluminum doped zinc oxide nanoparticles were prepared by soft chemical method. The prepared nanoparticles were characterized by XRD, SEM-EDAX, UV-Vis, PL and FT-IR studies. XRD patterns revealed that the nanoparticles were crystallized in hexagonal wurtzite structure with an average particle size of 19 nm to 26 nm. The surface morphology was explored using SEM micrographs. The incorporation of aluminum was confirmed by EDAX and FT-IR studies. The band gaps of the particles were found from 3.48 eV to 3.53 eV through UV-Vis spectral studies. The defect related mechanism was investigated using PL measurements. The chemical functional groups in FT-IR spectra proved the formation of pure and aluminum doped zinc oxide nanoparticles.

7

Deposition of Zinc Oxide on the Materials Used in Medicine. Preliminary Results

Teterycz H, Suchorska-Woźniak P, Fiedot M, Karbownik I

Fibres & Textiles in Eastern Europe

|

2014

|

Vol. 22, no. 3 (105)

126--132

EN

This paper presents preliminary results of the direct deposition of nano- and microstructures of zinc oxide on materials used in medicine. The coatings were deposited on cotton gauze and polyamide fabric. During the research the biological activity of these materials was defined. Performed were also tests of doping the ZnO structures with silver obtained. The research has proved that there is a growth of zinc oxide structures both on the gauze and polyamide fabric. The nanostructures deposited on it did not become detached from the surface, even though the material was subjected to ultrasonic rinsing. In addition, good biocidal properties of both of the textile materials modified were found. Furthermore a complex surface analysis of catheters: vascular and urological was made. ZnO was deposited on catheters, but they were characterised by low adhesion.

PL

W artykule przedstawiono wstępne wyniki badań bezpośredniego osadzania nano- i mikrostruktur tlenku cynku na materiałach stosowanych w medycynie. Warstwy osadzono na gazie opatrunkowej, tkaninie poliamidowej oraz cewnikach wykonanych z politetrafluoroetylenu. Podczas badań określono aktywność biologiczną czystej oraz pokrytej ZnO gazy opatrunkowej i tkaniny poliamidowej. Wykonano również próby domieszkowania otrzymywanych struktur ZnO srebrem. Badania wykazały, że na analizowanych materiałach zachodzi wzrost struktur tlenku cynku. Stwierdzono dobre właściwości biobójcze zmodyfikowanych materiałów włókienniczych. Ponadto przeprowadzono kompleksową analizę powierzchni cewników naczyniowych i urologicznych. Na ich powierzchni również tworzyły się warstwy tlenku cynku, lecz charakteryzowały się niską adhezją .