Magnetic and optical properties of silica-gel glass containing iron oxide fine particles

1997 ◽  
Author(s):  
Atsuo Yasumori ◽  
Hironari Matsumoto ◽  
Shigeo Hayashi ◽  
Kiyoshi Okada
Keyword(s):  
Optical Properties ◽  
Iron Oxide ◽  
Silica Gel ◽  
Fine Particles

TEM observation of iron oxide pillars in montmorillonite

1990 ◽  
Vol 48 (4) ◽  
pp. 882-883
Author(s):  
H. Mori ◽  
Y. Murata ◽  
H. Yoneyama ◽  
H. Fujita
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Fine Particles ◽  
Aqueous Suspension ◽  
Volume Ratio ◽  
Exchange Capacity ◽  
Nano Composites ◽  
Pillared Montmorillonite ◽  
Topographic Features ◽  
Transmission Electron

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.

scholarly journals The Impact of Intense Winter Saharan Dust Events on PM and Optical Properties at Urban Sites in the Southeast of the Iberian Peninsula

Atmosphere ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1469
Author(s):  
Alba López-Caravaca ◽  
Ramón Castañer ◽  
Alvaro Clemente ◽  
Eduardo Yubero ◽  
Nuria Galindo ◽  
...  
Keyword(s):  
Optical Properties ◽  
Iberian Peninsula ◽  
Fine Particles ◽  
Saharan Dust ◽  
Percentile Method ◽  
Angstrom Exponent ◽  
Ångström Exponent ◽  
Dust Events ◽  
The Impact ◽  
Ångstrom Exponent

The influence of three Saharan dust events (SDE) on particulate matter (PM) concentrations and aerosol optical properties (AOP) during February 2021 was studied. The physical characteristics of the African aerosol were different for each episode. Therefore, the impacts of the three events on PM and AOP were analyzed separately. The monitoring sites were placed in Elche, in the southeast of the Iberian Peninsula. The sites can be classified as urban background locations. The procedure used to obtain the contribution of SDE to PM10 mass concentrations was the 40th percentile method. Nearly half of the days during the study period were under the influence of Saharan air masses. The average contribution of mineral dust (MD) to the PM10 mean concentration was ~50%, which was the highest contribution during the month of February in the last 14 years. The results show that those events characterized by a high input of fine particles (PM1 and PM2.5) caused larger increases in the absorption (σap) and scattering (σsp) coefficients than SDE in which coarse particles predominated. Nevertheless, as expected, SAE (Scattering Angström Exponent) values were lowest during these episodes. AAE (Absorption Angström Exponent) values during SDE were slightly higher than those observed in the absence of African dust, suggesting some contribution from MD to the absorption process.

scholarly journals Comparison of Optical Properties of Eu3+Ions in the Silica Gel Glasses Obtained by Different Preparation Techniques

1996 ◽  
Vol 90 (2) ◽  
pp. 461-468 ◽  
Author(s):  
J. Legendziewicz ◽  
W. Stręk ◽  
J. Sokolnicki ◽  
B. Keller ◽  
M. Borzechowska
Keyword(s):  
Optical Properties ◽  
Silica Gel ◽  
Gel Glasses ◽  
Preparation Techniques

scholarly journals Optical properties of atmospheric fine particles near Beijing during the HOPE-J<sup>3</sup>A Campaign

2015 ◽  
Vol 15 (22) ◽  
pp. 33675-33730
Author(s):  
X. Xu ◽  
W. Zhao ◽  
Q. Zhang ◽  
S. Wang ◽  
B. Fang ◽  
...  
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Fine Particles ◽  
Complex Refractive Index ◽  
Single Scattering ◽  
Single Scattering Albedo ◽  
Organic Mass ◽  
Absorption Coefficients ◽  
Aerosol Composition ◽  
Inorganic Species

Abstract. The optical properties and chemical composition of PM1.0 (particulate with an aerodynamic diameter of less than 1.0 μm) particles in a suburban environment (Huairou) near the mega-city Beijing were measured during the HOPE-J3A (Haze Observation Project Especially for Jing-Jin-Ji Area) field campaign. The campaign covered the period November 2014 to January 2015 during the winter coal heating season. The average and standard deviations for the extinction, scattering, absorption coefficients, and the aerosol single scattering albedo (SSA) at λ = 470 nm during the measurement period were 201 ± 240, 164 ± 202, 37 ± 43 Mm-1, and 0.80 ± 0.08, respectively. The mean mass scattering (MSE) and absorption (MAE) efficiencies were 4.77 ± 0.01 and 0.87 ± 0.03 m2g-1, respectively. Highly time-resolved air pollution episodes clearly show the dramatic evolution of the PM1.0 size distribution, extensive optical properties (extinction, scattering, and absorption coefficients) and intensive optical properties (single scattering albedo and complex refractive index) during haze formation, development and decline. Time periods were classified into three different pollution levels (clear, slightly polluted, and polluted) for further analysis. It was found that: (1) The diurnal patterns of the aerosol extinction, scattering, absorption coefficients, and SSA differed for the three pollution classes. (2) The real and imaginary part of complex refractive index (CRI) increased, while the SSA decreased from clear to polluted days. (3) The relative contributions of organic and inorganic species to observed aerosol composition changed significantly from clear to polluted days: the organic mass fraction decreased (50 to 43 %) while the proportion of sulfates, nitrates, and ammonium increased strongly (34 to 44 %). (4) The fractional contribution of chemical components to extinction coefficients was calculated by using the modified IMPROVE algorithm. Organic mass was the largest contributor (58 %) to the total extinction of PM1.0. When the air quality deteriorated, the change of the relative contribution of sulfate aerosol to the total extinction was small, but the contribution of nitrate aerosol increased significantly (from 17 % on clear days to 23 % on polluted days). (5) The observed mass scattering efficiencies increased consistently with the pollution extent, however, the observed mass absorption efficiencies increased consistently with increasing mass concentration in slightly pollution conditions, but decreased under polluted conditions.

Synergistic photo optical and magnetic properties of a hybrid nanocomposite consisting of a zinc oxide nanorod array decorated with iron oxide nanoparticles

2018 ◽  
Vol 6 (39) ◽  
pp. 10502-10512 ◽  
Author(s):  
Brandon Azeredo ◽  
Anne Carton ◽  
Cédric Leuvrey ◽  
Céline Kiefer ◽  
Dris Ihawakrim ◽  
...  
Keyword(s):  
Zinc Oxide ◽  
Magnetic Properties ◽  
Optical Properties ◽  
Iron Oxide ◽  
Iron Oxide Nanoparticles ◽  
Nanorod Array ◽  
Oxide Nanoparticles ◽  
Hybrid Nanocomposite ◽  
Optical And Magnetic Properties

A ZnO/PBA/Fe3−δO4 nanocomposite displays enhanced magnetic and optical properties as a result of dual synergy.

Optical Properties and Structural Changes in Semiconductor Fine Particles

1999 ◽  
pp. 19-30
Author(s):  
Tosihiro Arai ◽  
Seinosuke Onari ◽  
Kiyoto Matsuishi ◽  
Toshiharu Makino ◽  
Takaaki Orii
Keyword(s):  
Optical Properties ◽  
Structural Changes ◽  
Fine Particles

Optical properties of Zn fine particles coated with ZnO and/or ZnS

1996 ◽  
Vol 99 (12) ◽  
pp. 987-991 ◽  
Author(s):  
Jianfeng Xu ◽  
Jianrong Zhang ◽  
Weiping Ding ◽  
Wei Yang ◽  
Guangxu Cheng ◽  
...  
Keyword(s):  
Optical Properties ◽  
Fine Particles
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