Preparation and Properties of Zinc Oxide and Titanium Oxide Ultra-Fine Composite Particles for Attenuation of Ultraviolet Radiation

A co-precipitation preparation method and the properties of an ultraviolet (UV)-attenuating agent are described in this paper. The composite particles of ultra-fine zinc oxide and titanium oxide are used to attenuate UV radiation. Preparation of TiOSO4, ZnCl2 solution and the co-precipitation of the composite particles by alkali are included during the process. Various types of surfactants have been used to modify the composite particles. Particle sizes are determined by laser particle analyzer, and reflectance and absorption coefficient are determined by UV-VIS spectrophotometer. Results show that particle size of the composite particles as well as total reflectance and absorption coefficient depend on the surfactants, pH value, and carline temperature. The average sizes of zinc oxide and titanium oxide ultra-fine particles range from39 to 65 nm. Attenuation capability of ultraviolet radiation becomes stronger when the particle average sizes becomes smaller. Composites less than 40 nm with titanium oxide of rutile phase attenuate most effectively the ultraviolet radiation ranging from 280 nm to 390 nm.

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Preparation and Properties of Zinc Oxide and Titanium Oxide Ultra-Fine Composite Particles for Attenuation of Ultraviolet Radiation

Key Engineering Materials - High-Performance Ceramics IV ◽

10.4028/0-87849-410-3.822 ◽

2007 ◽

pp. 822-825

Author(s):

Jing Ran ◽

Ping Zhang ◽

Wei Zhong Yang ◽

Da Li Zhou ◽

Heng Liu ◽

...

Keyword(s):

Zinc Oxide ◽

Ultraviolet Radiation ◽

Titanium Oxide ◽

Composite Particles

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Synthesis of ultra-fine particles of strontium hexaferrite by a modified co-precipitation method

Journal of the European Ceramic Society ◽

10.1016/s0955-2219(01)00149-2 ◽

2001 ◽

Vol 21 (10-11) ◽

pp. 1951-1955 ◽

Cited By ~ 104

Author(s):

A. Ataie ◽

S. Heshmati-Manesh

Keyword(s):

Fine Particles ◽

Precipitation Method ◽

Strontium Hexaferrite ◽

Ultra Fine Particles ◽

Co Precipitation

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FLOCCULATION STUDY OF NATURAL QUARTZ SAMPLE USING ANIONIC POLYACRYLAMIDE

Contemporary Materials ◽

10.7251/comen2002112s ◽

2020 ◽

Vol 11 (2) ◽

Author(s):

Ljiljana Tankosić ◽

Svjetlana Sredić ◽

Pavle Tančić ◽

Zoran Nedić

Keyword(s):

Fine Particles ◽

Ph Value ◽

Distribution Analysis ◽

Quartz Sample ◽

Natural Quartz ◽

Liquid Component ◽

Hindered Settling ◽

The Republic ◽

Ultra Fine Particles ◽

Anionic Polyacrylamide

The waste sludge generated during processing of iron ore in the Omarska mine (The Republic of Srpska, Bosnia and Herzegovina) is fine-grained (15μm), containing relatively high concentrations of iron, and quartz as its major impurity. The flocculation behaviour of the primary natural raw “quartz” sample from Omarska mine was studied in the present paper. This sample is composed of major quartz which dominates over minor contents of clay minerals and feldspars, and contain 92.9% of SiO2. Particle size distribution analysis confirm that it is present as fine and ultra-fine particles. The zeta potential of quartz depends on pH value. Settling experiments were performed by using three different dispersants (Na-hexamethaphosphate, Na-pyrophosphate and Na-silicate), and anionic polyacrylamide as flocculants. The best results were achieved with Nahexametaphosphate (1000 g/t) and anionic polyacrylamide A 100. The effect of a flocculant on the settling rate depends on solid concentration. Settling rates increase significantly with the increase of the liquid component in both cases (natural settling and hindered settling by addition of a flocculant).

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Studies of copper selenide ultrafine particles by newly developed gas evaporation method

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100174667 ◽

1990 ◽

Vol 48 (4) ◽

pp. 306-307

Author(s):

Chihiro Kaito ◽

Yoshio Saito

Keyword(s):

Crystal Structure ◽

Ultrafine Particles ◽

Fine Particles ◽

Production Method ◽

Atmospheric Temperature ◽

Copper Selenide ◽

Quartz Boat ◽

Selenium Vapor ◽

Ar Gas ◽

Ultra Fine Particles

The direct evaporation of metallic oxides or sulfides does not always given the same compounds with starting material, i.e. decomposition took place. Since the controll of the sulfur or selenium vapors was difficult, a similar production method for oxide particles could not be used for preparation of such compounds in spite of increasing interest in the fields of material science, astrophysics and mineralogy. In the present paper, copper metal was evaporated from a molybdenum silicide heater which was proposed by us to produce the ultra-fine particles in reactive gas as shown schematically in Figure 1. Typical smoke by this method in Ar gas at a pressure of 13 kPa is shown in Figure 2. Since the temperature at a location of a few mm below the heater, maintained at 1400° C , were a few hundred degrees centigrade, the selenium powder in a quartz boat was evaporated at atmospheric temperature just below the heater. The copper vapor that evaporated from the heater was mixed with the stream of selenium vapor,and selenide was formed near the boat. If then condensed by rapid cooling due to the collision with inert gas, thus forming smoke similar to that from the metallic sulfide formation. Particles were collected and studied by a Hitachi H-800 electron microscope.Figure 3 shows typical EM images of the produced copper selenide particles. The morphology was different by the crystal structure, i.e. round shaped plate (CuSe;hexagona1 a=0.39,C=l.723 nm) ,definite shaped p1 ate(Cu5Se4;Orthorhombic;a=0.8227 , b=1.1982 , c=0.641 nm) and a tetrahedron(Cu1.8Se; cubic a=0.5739 nm). In the case of compound ultrafine particles there have been no observation for the particles of the tetrahedron shape. Since the crystal structure of Cu1.8Se is the anti-f1uorite structure, there has no polarity.

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