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Exploitation of industrial solid wastes for preparing zeolite as a value-added product and its kinetics as adsorbent for heavy metal ions

Abdel-Hameed Reham Mohamed, Abdel-Aal Elsayed A., Farghaly Fatma E., Ibrahim Ibrahim A., Abdel Khalek Mohamed A., Ahmed Mohamed A., Abdel-Messih Micheal F.

Physicochemical Problems of Mineral Processing

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2021

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Vol. 57, iss. 1

87--99

EN

Aluminum and fumed silica as solid industrial wastes were converted to zeolite NaPas a value-addedproduct without any template. The hydrothermal process was optimized using static autoclave. The crystallization was carried out at 100, 120 and 150°C for 24, 48 and 72 h. The prepared zeolite of Si:Al ratio of 1.2 was characterized using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) provided with Energy Dispersive Spectroscopy (EDS), Surface Area, Fourier Transmitted Infra-Red (FTIR) and Thermal Analysis (TG-DSC). The crystalline phase was formed at 100°Cafter 72 hours and at 120°C after 48 hours, while it was formed after 24 honlyat 150°C. Increasing temperature and time lead to the conversion of the prismatic gibbsite crystals into plate-like structure of zeolitewhich is then formedcauliflower-like structure.The prepared zeolite was employed as adsorbent for Ni2+and Cu2+ions from aqueous solution.The kinetic studies of adsorption processes were performed.

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Direct formation of ZnO nanorods by hydrothermal process: study on its optical properties and electron transport

Mufti N., Fuad A., Fibriyanti A. A., Maryam S., Kurniawan R., Taufiq A., Sunaryono, Rusydi A.

Materials Science Poland

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2020

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Vol. 38, No. 1

91--96

EN

We report a new direct fabrication of the ZnO nanorods (NR) by hydrothermal method, in which the preparation of seed layer is eliminated. We show that the tuning of initial temperature rate during the hydrothermal process plays a key role in the structural modification of the ZnO NR. A highly oriented ZnO NR is successfully fabricated by using a low rate of initial temperature. The increase of optical absorption and electron transport was obtained by reducing the diameter and increasing distribution of the ZnO NR on the substrate. Interestingly, an additional absorption from the defects is obtained in the system, which plays an important role in expanding the optical absorption. Our system will provide a favourable characteristic for developing the high-performance optoelectronic devices with high optical absorption and high electron transport.

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Synthesis of ZnO-CuO flower-like hetero-nanostructures as volatile organic compounds (VOCs) sensor at room temperature

Sabry R. S., Alkareem R. A. S. A.

Materials Science Poland

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2018

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Vol. 36, No. 3

452--459

EN

ZnO-CuO flower-like hetero-nanostructures were successfully prepared by combining hydrothermal and dip coating methods. Flower-like hetero-nanostructures of ZnO-CuO were examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and UV-Vis. The sensing properties of ZnO-CuO flower-like hetero-nanostructures to volatile organic compounds (VOCs) were evaluated in a chamber containing acetone or isopropanol gas at room temperature. The sensitivity of ZnO-CuO flower-like hetero-nanostructures to VOCs was enhanced compared to that of pure leafage-like ZnO nanostructures. Response and recovery times were about 5 s and 6 s to 50 ppm acetone, and 10 s and 8 s to 50 ppm isopropanol, respectively. The sensing performance of ZnO-CuO flower-like hetero-nanostructures was attributed to the addition of CuO that led to formation of p-n junctions at the interface between the CuO and ZnO. In addition, the sensing mechanism was briefly discussed.

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Hydrothermal synthesis and characterization of polycrystalline gadolinium aluminum perovskite (GdAlO3, GAP)

Girish H. N., Basavalingu B., Shao G. Q., Sajan C. P., Verma S. K.

Materials Science Poland

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2015

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Vol. 33, No. 2

301--305

EN

Gadolinium aluminum perovskite (GdAlO3, GAP) is a promising high temperature ceramic material, known for its wide applications in phosphors. Polycrystalline gadolinium aluminum perovskites were synthesized using a precursor of co-precipitate gel of GdAlO3 by employing hydrothermal supercritical fluid technique under pressure and temperature ranging from 150 to 200 MPa and 600 to 700 degrees C, respectively. The resulted products of GAP were studied using the characterization techniques, such as powder X-ray diffraction analysis (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM) and energy dispersive analysis of X-ray (EDX). The X-ray diffraction pattern matched well with the reported orthorhombic GAP pattern (JCPDS-46-0395).

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Własności termiczne wybranych materiałów budowlanych

Gawin D., Jabłoński M., Wojtatowicz T., Rożniakowski K.

Izolacje

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2000

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R. 5, nr 1

30-34

PL

Do analizy procesów cieplno-wilgotnościowych za chodzących w materiałach budowlanych niezbędna jest znajomość ich własności fizycznych. Niezależnie od modelu stosowanego do opisu tych zjawisk, [1] zwykle konieczna jest znajomość własności termicznych, tj. współczynnika przewodzenia ciepła i pojemności cieplnej, rozpatrywanych materiałów w różnych stanach zawilgocenia i temperaturach.