ISSN:
1013-9826
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
In this work, we encapsulated the titanium oxide particles with a layer of Al2O3 by asol-gel process and investigated the UV-shielding properties of the obtained Al2O3-TiO2 composites.In this method, Al(NO3)3 aqueous solution mixed with raw titanium oxide powder was hydrolyzedby adding NH3·H2O. The hydrated materials were calcined at 500°C and then the composite ofAl2O3-TiO2 was prepared. Different techniques including ICP-AES, XRD, SEM-EDS, and TEMwere used to characterize the raw TiO2 and encapsulated TiO2 particles. Chemical analysis showedthat TiO2 mass content in the raw titanium oxide particles is 98.25%, and Al2O3 is just 0.75%. Aftermodification, the percentage Al2O3 was increased to 4.48% due to the encapsulation of Al2O3. Traceelements analysis displayed that the concentration of the trace elements were much lower than theiroriginal content in the raw titanium oxide, which prove that proved that there was no impuritiesincorporated into in the sol-gel process. XRD analysis indicated that the modified titanium oxidepowders are mainly in phase of rutile, ca. 99.1%, and the profiles exhibit no peaks of crystallineAl2O3 suggesting the layer of Al2O3 exists in amorphous phase. SEM image suggests that the size isin 80~600nm of the raw TiO2 granula and became rougher on the surface, the packing of theagglomerations got looser after modification with Al2O3. HRTEM image shows that the TiO2particles was evenly coated with a packed layer ~8 nm in thickness. The UV-Vis absorbencyexperiments showed that the range of wavelength shielded was narrowed from 208-316 nm in theraw titanium oxide to 225-285 nm in the case of the Al2O3-TiO2. The average absorbency of UVwas improved from 1.07 to 1.98 at the same content 1.0 μg/mL in the suspended solution. Theresults reflected that Al2O3 modification process improve the titanium oxide particles UV-shieldingproperties in selectivity and performance
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/01/57/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.373-374.706.pdf
