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Optical Properties Of Nano-semiconductor-materials And Their Applications

Posted on:2004-08-17Degree:DoctorType:Dissertation
Country:ChinaCandidate:B H WangFull Text:PDF
GTID:1101360095953652Subject:Materials science
Abstract/Summary:PDF Full Text Request
Nano -semiconductor- inorganic materials have special UV-Vis optical properties. Diffuse reflect and water-suspend absorption UV-Vis spectrum of some of nano -semiconductor- inorganic materials were researched in this thesis. But their shield properties were emphasized. And then latex paint , polypropylene and polyester powder paint modified by nano -semiconductor- inorganic materials were studied.From diffuse reflect spectrum, qualitative analysis results, such as absorption and reflection character, of UV-Vis optical properties of nano-materials can be gotten. The results indicate that the optical properties of nano- semiconductor- inorganic materials nearly relate to their band energy. Nano-TiO2 and ZnO have strong absorption in UV light area but intense reflection in visible region. They are very good UV- absorbent. Nano-SiO2 strongly reflect light in whole UV-Vis region. But have a variable strength absorption apex near wavelength is about 230nm. This result can be used to clarify the controversy on nano- SiO2 's absorption or reflection to UV light.The UV-shield property of suspend of definite thickness nano-material can be studied through water-disperse system absorption spectrum. On light consistency, the absorption apex of nano-material disperse system include the real absorption of nano-materials, and scattering of nano-particles besides. The nano-material disperse system follow the rule of Rayleigh and Mie scattering. The absorption band in UV region is the addition of real absorption and scattering. Rutile-nano- TiO2 have the most stronglyabsorption at the same thickness. TiO2 used for paints and micron ZnO have very weak UV-light absorption. And the absorption strength of multi-nano-material disperse system is greater than the singleness system. This is result from that cooperativity between absorption and scattering in multiplex system.Latex paint modified by multi-nano -semiconductor- inorganic materials were studied. The resistance to aging of modified paints is greatly improved, and at the same time, the scrub resistance and water resistance are improved.Mechanics properties of polypropylene filled with nano- TiO2 were studied. And relationship of mechanics properties and irradiation time was studied. Infrared spectrum was used to research the mechanism of the ageing of polypropylene. It is made sure that polypropylene filled only nano- TiO2 have bad resistance to aging. The mechanism of polypropylene ageing haven't changed by filling with nano-TiO2. When filled with nano-TiO2 and UV- absorbent and stabilizer, The resistance to aging of polypropylene was greatly improved.Nano-materials were at first time used to modified polyester powder paint in this paper. The resistance to aging of modified polyester powder paint is greatly improved.
Keywords/Search Tags:nano -semiconductor- inorganic materials, nano-TiO2, nano-ZnO, nano-SiO2, UV-Vis spectrum, latex paint, polypropylene, polyester powder paint resistance to aging
PDF Full Text Request
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