Wyniki wyszukiwania - BazTech

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Novel nanofibers composite based clay : synthesis, characterization and intrinsic properties

El Omari Youssef, Kbiri Zakaria, Tbib Bouazza, Abouharim Abdelhafid, El-Hami Khalil

Physicochemical Problems of Mineral Processing

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2023

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Vol. 59, iss. 1

art. no. 161679

EN

This work focuses on the study of red brick doped with reed fibers. These properties have been studied using characterizations techniques. In this context, we used Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis on the stability configuration, chemical structures and surface properties (morphology and porosity). The synthesis protocol is followed according to the manufacturing process of bricks on an industrial scale with well-defined standards and specifications. SEM and XRD experimental results showed that doping of clay fibers could effectively increase pore size and grain size as an indication of the removal of non-crystalline cellulosic materials from the fibers. The benefits of using fiber additives in clay bricks are then confirmed from a performance and environmental point of view.

2

Structural, morphological, and optical properties of AgxO thin films deposited via obliquely angle deposition

Soltane H. Ben, Akkari F. Chaffar, Gallas B., Kanzari M.

Materials Science Poland

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2023

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Vol. 41, No. 1

27--41

EN

This work reports on the optical, structural, and morphological properties of silver oxide thin films obtained by postoxidation of silver deposited previously by the thermal evaporation technique. The samples were deposited on glass substrates using the oblique angle deposition technique for different angles of incidence γ (γ=0°, 20°, 40°, 60°, 75°, and 85°). γ is defined as the angle between the particle flux and the normal to the substrate. The resulting thin films were annealed in the free air at two temperatures (300°C and 400°C). X-ray diffraction (XRD), scanning electron microscopy (SEM), and UV-visible-NIR spectrophotometer were performed to study the crystal structure, as well as the morphological and optical properties (transmittance and reflectance), of the AgxO samples. X-ray diffraction analysis revealed the presence of the AgxO phase for the silver films deposited at a high angle of incidence and for the annealing temperature 300°C. In contrast, the diffractograms of the silver films annealed at 400°C show an amorphous behavior. Optical results indicated that the direct band gap energy increases pursuant to increasing the angle of incidence γ. The absorption coefficients of AgxO thin films were found to be in the range of 103–105 cm−1. Additionally, we determined the birefringence for the layers annealed at 400°C and found that the highest value of birefringence is obtained corresponding to the angle of incidence 60°. Morphological analysis indicated that the porosity increases with the angle of incidence and highlights the amorphous nature of the films, which is attributed to the columnar structure.

3

Physical properties of ZnTe semiconductor thin films prepared by high vacuum resistive system

Abbas M., Shah N. A., Jehangir K., Fareed M., Zaidi A.

Materials Science Poland

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2018

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Vol. 36, No. 3

364--369

EN

Zinc telluride (ZnTe) polycrystalline films have been grown on well-cleaned glass substrates by thermal vacuum evaporation technique using 99.99 % pure ZnTe powder as an evaporant. The samples were prepared at different substrate temperatures, rates of evaporation and thicknesses. The X-ray diffraction was used to study the structure of the films. The structures of the samples were found to be polycrystalline with preferred (1 1 1) orientation. Transmission spectra of all ZnTe films were recorded in the range of 300 nm to 2500 nm. The films were electrically characterized using Hall effect measurements at room temperature. It has been stated that the electrical resistivity, mobility and carrier concentration are strongly influenced by the substrate temperature. From the SEM results, it is clear that the surface of ZnTe is very smooth with occasional large particles on it.

4

Topography and water wettability of HWVD produced (Pb,Sn)S2 thin films for solar cells

Tashlykov I., Turavets A., Gremenok V., Bente K., Unuchak D.

Przegląd Elektrotechniczny

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2010

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R. 86, nr 7

118-121

EN

Pb0,5Sn1,5S2 thin films were prepared by hot-wall vacuum deposition (HWVD) and effect of substrate temperature on structural and surface morphological properties was thoroughly investigated by means of X-ray diffraction, scanning electron microscopy, atomic force microscopy and water contact angle techniques, respectively. It is seen that contact angle measurements on (Pb,Sn)S2 films can be used to assess the quality of these materials prior to device fabrication

PL

Cienkie warstwy Pb0,5Sn1,5S2 wytworzono metodą gorącej ścianki. Metodami dyfrakcji promieni rentgenowskich, skaningowej mikroskopii elektronowej, mikroskopii sił atomowych i kąta zwilżania zbadano wpływ temperatury podłoża na strukturę i morfologię cienkich warstw. Ustalono, że badania kąta zwilżalności mogą być przydatne do określenia jakości warstw wykorzystywanych w ogniwach słonecznych.

5

Identification of Adducts Formed in the Reaction of the Bacterial Mutagen 3-Chloro-4-(chloromethyl)-5-hydroxy-2(5H)-furanone with Cytidine

Pluskota-Karwatka D., Munter T., Le Curieux F., Sjöholm R., Koroniak H., Kronberg L.

Polish Journal of Chemistry

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2007

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Vol. 81, nr 5-6

1145-1157

EN

3-Chloro-4-(chloromethyl)-5-hydroxy-2(5H)-furanone (CMCF), a strong bacterial mutagen reacts with cytidine in buffered aqueous solutions. The reaction products were separated by preparative HPLC C18 column chromatography and were structurally characterized by UV absorbance, 1H NMR and 13C NMR spectroscopy, and mass spectrometry. The main products were identified as 7-(-D-ribofuranosyl)-4-carboxy-6- oxo-6,7-dihydro-4H-pyrimido[1,6-alfa]pyrimidine-3-carbaldehyde (cM1FA-Cyd), and 7-(beta-D-ribofuranosyl)-6-oxo-6,7-dihydro-4H-pyrimido[1,6-alfa]pyrimidine-3-carbaldehyde (M1FA-Cyd). The highest yields of cM1FA-Cyd andM1FA-Cyd, being 12 and 1mol%respectively, were obtained in the reaction performed at pH 4.6 and 37 graduateC for 7 days. M1FA-Cyd and cM1FA-Cyd are structurally related to pfA-dR, the adduct previously identified in the reaction of 3-chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX) or 3-chloro-4-(chloromethyl)-5-hydroxy-2(5H)-furanone (CMCF) with 2'-deoxyadenosine.

6

Charakterystyka strukturalna metali odkształcanych w warunkach ściskania oscylacyjnego

Rodak K., Sobota J., Pawlicki J.

Rudy i Metale Nieżelazne

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2004

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R. 49, nr 4

184-188

PL

Przedstawiono wpływ parametrów ściskania oscylacyjnego na zmiany mikrostruktury miedzi i żelaza Armco. Otrzymane wyniki porównano z wynikami badań uzyskanymi w próbach ściskania konwencjonalnego. Przedstawione badania stanowią wstępny etap do szczegółowych badań zmian ilościowych substruktury.

EN

An effect of oscillatory compression parameters on the microstructure of Cu and Armco Fe has been presented. The results obtained were compared with those from a standard compression test. The tests carried out so far are preliminary stage of a detailed quantitative research on the substructure changes in these metals.

7

Porównanie właściwości adsorpcyjnych mikro-mezoporowatych węgli aktywnych i mezoporowatych adsorbentów krzemionkowych

Choma J.

Inżynieria i Ochrona Środowiska

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2002

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T. 5, nr 1

67-78

PL

Porównano właściwości adsorpcyjne powszechnie znanych i szeroko stosowanych adsorbentów węglowych - węgli aktywnych oraz nowych dobrze uporządkowanych adsorbentów krzemionkowych - MCM-41. Dla dwóch przemysłowych, syntetycznych węgli aktywnych Ambersorb 563 (WA AM 563) i 572 (WA AM 572) (z firmy Rohm and Haas Company, Filadelfia, PE, USA) oraz dwóch adsorbentów krzemionkowych MCM-41 C8 i C16 (zsyntezowanych w laboratorium Wojskowej Akademii Technicznej, Warszawa, Polska) wyznaczono metodą objętościową (za pomocą analizatora adsorpcyjnego ASAP-2010 z firmy Micromeritics, Norcross, GA, USA) niskotemperaturowe (77 K) izotermy adsorpcji azotu w szerokim przedziale ciśnień względnych od ok. 10-6 do ok. 1,0. Izotermy te stanowiły podstawę do obliczeń. Wykorzystując metodę Brunauera, Emmetta i Tellera (BET), porównawczą metodę [alfa]s Gregga i Singa oraz metodę wynikającą z teorii funkcjonału gęstości, wyznaczono powierzchnię właściwą BET, powierzchnię właściwą mezoporów węgli aktywnych i powierzchnię zewnętrzną adsorbentów krzemionkowych, objętość mikroporów węgli aktywnych oraz objętość pierwotnych mezoporów adsorbentów krzemionkowych, funkcje rozkładu objętości porów oraz wartości maksimum najbardziej charakterystycznych pików. Stwierdzono, że badane węgle aktywne są adsorbentami mikro-mezoporowatymi o powierzchni równej 565 m2/g (WA AM 563) i 1060 m2/g (WA AM 572) o wymiarach porów mniejszych od 1,0 nm i większych od 1,0 nm. Natomiast adsorbenty krzemionkowe są adsorbentami mezoporowatymi o powierzchni BET równej 866 m2/g (MCM-41 C8) i 1203 m2/g (MCM-41 C16) z maksimum funkcji rozkładu objętości dla średnicy 2,1 nm (C8) i 3,2 nm (C16). Przedstawione wyniki wskazują, że otrzymane adsorbenty krzemionkowe z rodziny MCM-41 są adsorbentami o bardzo dobrej jakości i wkrótce adsorbenty te mogą stać się konkurencyjnymi dla klasycznych węgli aktywnych w procesach oczyszczania wody i powietrza, a także w katalitycznych procesach przemysłowych. W pracy wykazano również dużą przydatność, do charakterystyki różnych materiałów porowatych, danych adsorpcji azotu wraz z trafnie wytypowanymi metodami analizy tych danych.

EN

The paper includes comparison of adsorption properties of commonly known and widely used carbonaceous adsorbents - active carbons and new well-ordered siliceous adsorbents - MCM-41. For two commercial synthetic active carbons Ambersorb 563 (WA AM 563) and 572 (WA AM 572) (from Rohm and Haas Company, Philadelphia, PE, USA), and for two siliceous adsorbents MCM-41 C8 and C16 (synthesized in laboratory of the Military Technical Academy, Warsaw, Poland), the low temperature (77 K) nitrogen adsorption isotherms, in the wide range of relative pressures from approx. 10-6 to approx. 1.0, were obtained using volumetric method (adsorption analyser ASAP-2010, Micromeritics, Norcross, GA, USA). These isotherms were bases for further calculations. Brunauer, Emmett and Teller (BET) method, Gregg and Sing [alpha]s-method, and density functional theory method were used to obtain specific surface area BET, specific surface area of mesopores of active carbons and external surface area of siliceous adsorbents, micropore volume of active carbons and primary mesopore volume of siliceous adsorbents, pore size distribution functions and maximum values of most characteristic peaks. It was found that studied active carbons are micro-mesoporous adsorbents with surface area equal to 565 m2/g (WA AM 563) and 1060 m2/g (WA AM 572), with pore dimensions smaller than 1.0 nm and greater than 1.0 nm, while siliceous adsorbents are mesoporous with BET surface area equal to 866 m2/g (MCM-41 C8) and 1203 m2/g (MCM-41 C16) with the maximum of volume distribution functions for diameters equal to 2.1 (C8) and 3.2 nm (C16). The presented results indicate that the obtained MCM-41 ordered siliceous adsorbents are high quality adsorbents and soon may become competitive for classic active carbons in water and air purification processes as well as in catalytic commercial processes. The paper also proves that nitrogen adsorption data with correctly chosen analyses methods are useful in characterising miscellaneous porous materials.