Wyniki wyszukiwania - Biblioteka Nauki

1

Morphology and properties of the graphene layer on the copper substrate

100%

Pietrzak K. , Olesińska W. , Strąk C. , Siedlec R. , Gładki A.

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tom Vol. 17, nr 4

104--108

EN

The aim of the work presented in the article was to clarify controversial comments about anti-corrosion and mechanical properties of graphene coatings, deposited on copper substrates. It was designed special experimental cycle comprising: preparation of graphene forms and copper, the observation of layers Cu / GO (rGO) after the thermal reduction processes and oxidative test in air at 150°C temperature and 350 h in time. The resulting coatings and graphene layers were subjected to tribological test for hardness. The observed differences in the continuity of the coverage copper surface by graphene forms, allowed to understand the macroscopic effect of increased hardness and wear resistance layers rGO/Cu.

2

Efficient and sensitive quantification of polar tobacco volatile organic compounds by a micro thermal-assisted sampling device using reduced graphene oxide coupling with thermal desorption-gas chromatography/mass spektrometry

88%

Lai Y. , Han B. , Wu J. , Weng S. , Chen S. , Wang J. , Wang Y. , Pan X. , Lin Y. , Tao H. , Zhang Z. , Li G.

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tom Vol. 36, no. 3

263--272

EN

It still remains a great challenge to selectively enrich and sensitively quantify the trace volatile organic compounds (VOCs) in real samples with complex matrix. In this study, an integration method combining a selective enrichment medium of reduced graphene oxide (rGO) with a specially designed micro thermal-assisted purge-and-trap sampling device was developed for efficient enrichment and sensitive quantification of trace tobacco VOCs coupling with thermal desorption (TD)-gas chromatography/ mass spectrometry (GC/MS). The prepared rGO has been proved to possess excellent enrichment selectivity and capacity for tobacco polar VOCs with the multi-layer structure, good thermal stability and large specific surface area. The specially designed sampling device was efficient and suitable for enriching and sampling trace polar tobacco VOCs coupling with rGO medium. Under the optimized sampling and analytical conditions, the established analytical method could be actually applied for quantification of typical tobacco polar VOCs with the good recoveries of 72.9–128% and the satisfied RSDs of 1.8–19.9% (n 5 3). The results suggested that the developed method was selective, sensitive and reliable for enrichment and quantification of trace tobacco polar VOCs.

3

One-step reduction, characterization and magnetic behaviour of exfoliated graphene oxide

88%

Dikio E. D. , Thema F. T. , Farah A. M. , Shooto N. D.

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tom Vol. 31, No. 1

59-64

EN

The functionalized graphene (GO) was fabricated by a simple method of chemical reduction in a polar aprotic solvent. This paper therefore, describes a versatile and synthetic route for the preparation of reduced graphene oxide (RGO) and its behavior when exposed to magnetic field environment. The characterization results of transmission electron microscopy (TEM), scanning electron microscopy (SEM), Raman spectroscopy and the attenuated total reflectance-Fourier transform infra-red (ATR-FTIR) analysis indicate that graphite was exfoliated and reduced to graphene layers.

4

The influence of reduced graphene oxide on the structure of the electrodes and the properties of dye-sensitized solar cells

63%

Dobrzański L. A. , Prokopiuk v. P. M.

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tom Vol. 77, nr 1

12--30

EN

Purpose of the paper: The aim of the research is to investigate the influence of the structure and chemical composition of the surface layers containing reduced oxide graphene on the properties of dye-sensitized solar cells, and to determine the correlation between the morphology and physicochemical properties of reduced graphene oxide and the electrical and optical properties of dye-sensitized solar cells, which will result in the desired effects reducing production costs and increasing the efficiency of dye cells. Design/methodology/approach: Complete manufacturing technology of dye-sensitized solar cells included the selection of the conditions of the thermal reduction of graphene oxide, the development of manufacturing technology of photoanode with and without reduced graphene oxide, the development of manufacturing technologies of counter electrodes with the reduced graphene oxide and the production of dye-sensitized solar cells by combining photoanode and counter electrode and filling the space between them by the electrolyte. Findings: A reduced graphene oxide layers applied to a glass substrate with transparent conductive oxide, used as a counter electrode and photoanode effect on reducing the degree of recombination and increasing electrochemical properties, which makes them important factors in increasing the efficiency of photovoltaic cells and reduce their manufacturing costs. Research limitations/implications: Dye-sensitized solar cells research develop in the direction to increase their efficiency and reduce manufacturing costs, among others, by modifying the chemical composition and structure of the main components: photoanode and counter electrode. Using one of the most expensive materials in the world - a platinum as a catalytic layer causes a significant increase in production costs. For this reason, it is important to search for new materials that can replace the expensive platinum. Practical implications: Developed in this work producing technology of photoanode and the counter electrode containing reduced graphene oxide is an attractive alternative to dye-sensitized solar cell by reducing the manufacturing cost by eliminating costly layer of platinum while maintaining a relatively high efficiency, high transmittance and low resistance of charge transfer at the interlayer counter electrode/electrolyte. Originality/value: In the paper, the reduced graphene oxide was applied as both photoanode and the counter electrode in dye-sensitized solar cells.

5

Wybrane właściwości użytkowe wodorozcieńczalnej żywicy akrylowej domieszkowanej tlenkiem grafenu - GO i zredukowanym tlenkiem grafenu - rGO

63%

Nasiłowska B. , Wojucki M. , Mierczyk J. , Djas M.

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tom nr 10

25--28

PL

W pracy przedstawiono wpływ zawartości tlenku grafenu GO i zredukowanego tlenku grafenu rGO na strukturę, połysk i zmianę charakterystyk odbiciowych powłoki lakierowej utworzonej z wodorozcieńczalnej żywicy akrylowej. Badania wykazały, że wzrost zawartości tlenku grafenu i zredukowanego tlenku grafenu nie powoduje zmian odbicia w zakresie promieniowania UV. W trakcie analizy uzyskanych wyników zaobserwowano, że w zakresie widzialnym 380 – 780 nm nastąpił wzrost i różnica w reflektancji, natomiast w zakresie bliskiej podczerwieni 780 – 2500 nm wartość reflektancji ulega zmniejszeniu. Analiza strukturalna powłok otrzymanych z wodorozcieńczalnej żywicy akrylowej z dodatkiem GO i rGO wykazała, że wprowadzenie pochodnych grafenu w formie proszku powoduje równomierne rozprowadzenie płatków grafenu i mniejszą koagulację niż w przypadku pasty, dzięki czemu nie obserwuje się pogorszenia właściwości aplikacyjnych i powłokotwórczych wodorozcieńczalnej żywicy lakierowej.

EN

The paper presents the influence of the content of graphene oxide GO and reduced graphene oxide rGO on the structure, gloss and change of the reflection characteristics of the varnish coating formed from water-borne acrylic resin. Studies have shown that the increase in graphene oxide and reduced graphene oxide content does not cause reflection changes in the UV range. During the analysis of the obtained results, it was observed that in the visible range 380 – 780 nm there was an increase and difference in reflectance, while in the near infrared range 780 – 2500 nm the value of reflectance decreases. Structural analysis of coatings obtained from waterborne acrylic resin with the addition of GO and rGO showed that the implementation of graphene derivatives in the form of a powder causes even distribution of graphene flakes and less coagulation than in the case of paste, so that no deterioration of application properties and coating-forming water- borne varnish resin.

6

Ocena skuteczności filtracji półmasek filtrujących wobec nanoaerozolu zredukowanego tlenku grafenu

51%

Makowski K. , Owczarek O. , Brochocka A.

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tom nr 8

17-21

PL

W artykule przedstawiono skuteczność filtracji półmasek filtrujących klasy FFP2 i FFP3 wobec nanocząstek zredukowanego tlenku grafenu. Sprzęt ochrony układu oddechowego został wybrany spośród wielu produktów powszechnie dostępnych na rynku. Pomiary penetracji przeprowadzono z użyciem 0,02-proc. zawiesiny wodnej zredukowanego tlenku grafenu przy przepływie nanoaerozolu 95 l/min. Wartość penetracji odczytywano dla cząstek o wielkości do 100 nm. Przedstawione wyniki badań pokazują, że stosowana obecnie klasyfikacja półmasek filtrujących według normy EN 149:2001+A1:2009, oparta na standardowych aerozolach testowych, nie ma przełożenia na ochronę przed nanoaerozolami zredukowanego tlenku grafenu. W przypadku zbadanych półmasek filtrujących wartości penetracji nanocząstek zredukowanego tlenku grafenu dla większości próbek przekroczyły dopuszczalny zakres określony we wspomnianej normie. W związku z tym konieczne jest opracowanie wytycznych doboru sprzętu ochrony układu oddechowego przeznaczonego do stosowania w warunkach obecności nanocząstek, w tym zredukowanego tlenku grafenu.

EN

The article presents the assessment of filtration efficiency of filtering half mask FFP2 and FFP3 against nanoparticles of reduced graphene oxide. Respiratory protective devices were selected from among many commonly available on the market. Penetration measurements were carried out with a 0.02% water suspension of reduced graphene oxide at a nanoaerosol flow of 95 l/ min. The penetration value was read for particles up to 100 nm in size. The presented research results show that the currently used classification of filtering respirators according to the EN 149:2001+A1:2009 standard, based on standard test aerosols, does not reflect the protection against reduced graphene oxide nanoaerosols. The penetration values against the graphene nanoparticles of the tested filtering half masks exceeded the admissible range of penetration according to the above-mentioned standard for most of the samples. Therefore, it is necessary to develop guidelines for the selection of respiratory protective equipment intended for use in the presence of nanoparticles, including reduced graphene oxide.