Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "porous silica" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-9 z 9
    Tytuł:
    Gas filling of SBA - 15 silica micropores probed by positron annihilation lifetime spectroscopy (PALS)
    Autorzy:
    Gorgol, M.
    Zaleski, R.
    Kierys, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/147961.pdf
    Data publikacji:
    2013
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    SBA-15 porous silica
    positron annihilation
    Opis:
    Positron annihilation lifetime measurements were conducted in situ while two gasses (nitrogen and oxygen, respectively) were introduced into the SBA-15 porous silica sample. Slow changes in lifetime spectra were observed during a long lasting gas interaction with the sample. Introduced gases slowly filled the free volumes, starting from the smallest ones, especially small micropores. In the presence of a gas, the rate of change of ortho-positronium (o-Ps) and unbound positron intensity was larger than the rate of change of lifetime. This suggests the existence of an additional process, which reduces the number of ortho-positronium atoms due to the interaction with the gas. Moreover, the process of filling pores with gas was slower than the process of emptying them while the gas was pumped out.
    Źródło:
    Nukleonika; 2013, 58, 1; 229-233
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Collection of Industrial Oil Using Nanoparticles and Porous Powders of Silica
    Autorzy:
    Cho, Y.-S.
    Moon, J.-W.
    Powiązania:
    https://bibliotekanauki.pl/articles/351139.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    silica nanopowders
    surface modification
    porous silica
    oil removal
    Opis:
    Industrial oil was collected using hydrophobic silica powders. Silica nanopowder was modified with octadecyltriethoxysilane (OTS) using spray pyrolysis reactor continuously. Besides nanoparticles, mesoporous silica powder synthesized using Pluronic P104 was adopted as another oil adsorbents. Spherical macroporous or meso-macroporous silica particles were prepared by selfassembly for the removal of oil. The effects of the amount of powder on the oil adsorption were studied and compared with the results of various silica powders. The meso-macroporous silica particles were found to be the most efficient, indicating that both specific surface area and porosity played crucial role.
    Źródło:
    Archives of Metallurgy and Materials; 2017, 62, 2B; 1371-1375
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fabrication of Porous Silica Fibers by Electrospinning for Sound Absorbing Materials
    Autorzy:
    Cho, Y.-S.
    Lee, H. J.
    Powiązania:
    https://bibliotekanauki.pl/articles/353561.pdf
    Data publikacji:
    2018
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    electrospinning
    porous silica fiber
    thermal insulator
    sound absorption
    Opis:
    Macroporous silica fibers having spherical cavities were fabricated by electrospinning using the spinning solution prepared from the mixed dispersion of tetraethylorthosilicate (TEOS) and polystyrene nanospheres as precursor and sacrificial templates, respectively, by injection through metallic nozzle. By applying electric field, the electro-spun fibers obtained by evaporation-driven self-assembly were collected on flat substrate or rotating drum, followed by the removal of the templates by calcination. The sound absorption coefficient of the porous fibers was measured by impedance tube, and the measured value was larger than 0.9 at high frequency region of incident waves. The surface of the resulting fibers was modified using fluorine-containing silane coupling agent to produce superhydrophobic fibrous materials to prevent the infiltration of humidity.
    Źródło:
    Archives of Metallurgy and Materials; 2018, 63, 3; 1497-1502
    1733-3490
    Pojawia się w:
    Archives of Metallurgy and Materials
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Synthesis and characterization of iron - cobalt nanoparticles embedded in mesoporous silica MCM - 41
    Autorzy:
    Surowiec, Z.
    Wiertel, M.
    Budzyński, M.
    Gac, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/147878.pdf
    Data publikacji:
    2013
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    cobalt
    iron
    MCM-41 porous silica
    Mössbauer effect
    superparamagnetic nanoparticles
    Opis:
    Fe1.xCox/MCM-41 nanocomposite materials were prepared by wet impregnation of the silica mesoporous support with aqueous solution of iron and cobalt salt mixtures. Samples, after calcination, were reduced at 573 K in order to obtain homogeneous distribution of (Fe-Co)3O4 oxide species over the MCM-41 support. Bimetallic systems were achieved through high temperature reduction, carried out at 1073 K. The temperature-programmed reduction studies indicated complex nature of the oxide species. The phase analysis of the obtained samples after low temperature reduction process carried out by means of X-ray diffraction method and using 57Fe Mossbauer spectroscopy revealed the presence of nanostructured magnetite- and maghemite-like phases. The samples with higher cobalt contents (x . 0.2) contained additionally bimetallic phases. The complete transformation of oxide phases to bimetallic Fe-Co systems occurred during reduction process in hydrogen at 1073 K. It was observed that high temperature processing caused partial transformation of highly dispersed iron oxide nanocrystallites into fayalite species embedded in the silica walls.
    Źródło:
    Nukleonika; 2013, 58, 1; 87-92
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Influence of annealing temperature on structural and magnetic properties of MnFe2O4 nanoparticles
    Autorzy:
    Surowiec, Z.
    Wiertel, M.
    Gac, W.
    Budzyński, M.
    Powiązania:
    https://bibliotekanauki.pl/articles/146127.pdf
    Data publikacji:
    2015
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    manganese ferrite
    MCM-41 porous silica
    Mössbauer effect
    superparamagnetic nanoparticles
    Opis:
    Nanoparticles of manganese ferrite were obtained by the impregnation of highly ordered mesoporous MCM-41 silica support. The investigated sample contained 20% wt. Fe. The obtained nanocrystallites were strongly dispersed in silica matrix and their size was about 2 nm. The sample annealing at 500°C led to increase of particle size to about 5 nm. The Mössbauer spectroscopy investigations performed at room temperature show on occurrence of MnFe2O4 nanoparticle in superparamagnetic state for the sample annealed in all temperatures. The coexistence of superparamagnetic and ferromagnetic phase was observed at liquid nitrogen temperature. The sample annealed at 400°C and 500 °C has bigger manganese ferrite particle and better crystallized structure. One can assign them the discrete hyperfi ne magnetic field components.
    Źródło:
    Nukleonika; 2015, 60, 1; 137-141
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    An application of Mössbauer spectroscopy in the studies of iron - molybdenum silica mesoporous materials
    Autorzy:
    Surowiec, Z.
    Wiertel, M.
    Marynowska, A.
    Gac, W.
    Zawadzki, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/147814.pdf
    Data publikacji:
    2013
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    iron
    MCM-41 porous silica
    molybdenum
    Mössbauer effect
    superparamagnetic nanoparticles
    Opis:
    Iron-molybdenum silica mesoporous materials were obtained by the application of direct hydrothermal method. Four samples with different metal contents relative to silica were investigated. Incorporation of iron and molybdenum ions in the synthesis stage led to structural changes of the MCM-41 support. With an increasing metals content, cylindrical pores of silica initially transformed into bottle-ink type pores, and then into the slit-like ones. Mössbauer spectroscopy investigations indicated that Fe ions were embedded in the silica walls and then formed nanosized crystallites in the pores. Superparamagnetic phase was observed at liquid nitrogen temperature.
    Źródło:
    Nukleonika; 2013, 58, 1; 137-141
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Positron annihilation study of iron oxide nanoparticles in mesoporous silica MCM-41 template
    Autorzy:
    Surowiec, Z.
    Wiertel, M.
    Zaleski, R.
    Budzyński, M.
    Goworek, J.
    Powiązania:
    https://bibliotekanauki.pl/articles/148449.pdf
    Data publikacji:
    2010
    Wydawca:
    Instytut Chemii i Techniki Jądrowej
    Tematy:
    positron annihilation
    Mössbauer effect
    MCM-41 porous silica
    superparamagnetic nanoparticles
    Opis:
    The subject of investigation were the samples obtained by impregnation of MCM-41 template with an aqueous solution prepared from Fe(NO3)3ź9H2O. As a result of such a procedure, iron oxides deposits on MCM-41 were formed. The Mössbauer studies revealed an occurrence of Fe3O4 nanocrystallites in the both ferri- and superparamagnetic states. Almost 80% small particles exist in a paramagnetic state. The positron annihilation lifetime spectroscopy (PALS) spectra were measured in air or in vacuum. The long-lived ortho-positronium (o-Ps) components and their intensities are time dependent due to air molecules interaction with iron oxide nanocrystallites and silica walls surfaces. The adsorption of air on the nanocrystallites surface causes a total screening of their surface and a raise of the o-Ps lifetime values. Observed anti-quenching effect is a result of competition of two phenomena: practically switching off a pick-off mechanism related to interaction of o-Ps with magnetite nanoparticles and considerably weaker usual quenching by paramagnetic oxygen molecules.
    Źródło:
    Nukleonika; 2010, 55, 1; 91-96
    0029-5922
    1508-5791
    Pojawia się w:
    Nukleonika
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Infrared studies and spectral properties of photochromic high silica glasses
    Autorzy:
    Girsova, M A
    Golovina, G F
    Drozdova, I.A.
    Polyakova, I G
    Antropova, T V
    Powiązania:
    https://bibliotekanauki.pl/articles/174765.pdf
    Data publikacji:
    2014
    Wydawca:
    Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
    Tematy:
    silica porous glass
    photochromic high silica glass
    transmission electron microscopy TEM
    X-ray diffraction (XRD)
    UV–VIS–IR transmission spectra
    Opis:
    The structure of photochromic high silica glasses (PHSGs) was studied by UV–VIS–NIR and IR spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD) techniques. PHSG plates were obtained by impregnation of silica porous glasses at first with AgNO3 aqueous solution (in or without the presence of the sensitizers, such as Cu(NO3)2 or Ce(NO3)3), next in the mixed halide salt (NH4Cl, KBr, KI) solution. Then a part of the samples was sintered at temperatures from 850 to 900 °C up to closing of the pores. The results of TEM study have shown that the PHSG plates have two-phase structure with inclusions of the size of 10–100 nm. According to XRD data, the PHSGs contain the AgBr phase. IR spectra confirmed the presence of AgI, AgCl, CeO2, CuCl2, CuCl phases in PHSGs.
    Źródło:
    Optica Applicata; 2014, 44, 2; 337-344
    0078-5466
    1899-7015
    Pojawia się w:
    Optica Applicata
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Effective removal of odors from air with polymer nonwoven structures doped by porous materials to use in respiratory protective devices
    Autorzy:
    Brochocka, Agnieszka
    Nowak, Aleksandra
    Panek, Rafał
    Kozikowski, Paweł
    Franus, Wojciech
    Powiązania:
    https://bibliotekanauki.pl/articles/1845379.pdf
    Data publikacji:
    2021
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    activated carbon
    zeolites
    porous materials
    polymer nonwoven structures
    mesoporous silica materials
    aplication
    Opis:
    Filtering Respiratory Protective Devices (FRPD) is not typically evaluated for exposure to volatile compounds, even though they significantly affect their protective performance. Such compounds are released into the atmosphere by industrial processes and pose serious health risks in people inhaling them. The adsorbent materials currently used to prevent those risks include activated carbon (AC). Zeolites and mesoporous silica materials (MCM) are very popular among the sorption materials. Due to their physical and chemical properties, they are able to adsorb significant amounts of volatile compounds from air. The melt-blown technology was used to produce filtering nonwovens with modifiers. As a result, polymer nonwoven structures with modifiers in the form of AC, zeolite (NaP1 type), molecular sieves (SM, SM 4Å) and mesoporous silica materials (MCM-41) were produced. The use of ACs (AC1 from Zgoda and AC2 from Pleisch) and their mixtures with others modifiers allowed to obtain satisfactory sorption, protective and utility properties. The longest breakthrough time against cyclohexane (approx. 53 min) was afforded by a variant containing AC, against ammonia (approx. 12 min) for the variant with AC2 and a mixture of AC2 and MCM-41. In the case of acetone vapor satisfactory breakthrough times were found for the variants with AC2 and AC1+SM (~20–25 min.). The present work deals with scientific research to improve workers’ and society’s health and safety by pursuing a better working life, and creating a safe social environment.
    Źródło:
    Archives of Environmental Protection; 2021, 47, 2; 3-19
    2083-4772
    2083-4810
    Pojawia się w:
    Archives of Environmental Protection
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-9 z 9

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies