Solid Solution of Titanium Dioxide in Aluminum Oxide

1966 ◽  
Vol 49 (12) ◽  
pp. 634-637 ◽  
Author(s):  
E. R. WINKLER ◽  
J. F. SARVER ◽  
IVAN B. CUTLER
1969 ◽  
Vol 73 (7) ◽  
pp. 2157-2162 ◽  
Author(s):  
Richard A. Slepetys ◽  
Philip A. Vaughan

2011 ◽  
Vol 284-286 ◽  
pp. 638-641
Author(s):  
Jun Cong Wei ◽  
Xiao Cui Han ◽  
Chun Hui Gao ◽  
Jian Kun Huang ◽  
Jun Bo Tu

MgO-Al2O3-TiO2 composite refractories were prepared by using magnesium aluminate spinel (MgAl2O4) and titanium dioxide as main starting materials and being sintered at high temperature. The influences of titanium dioxide additions on the room temperature physical properties, phase composition and microstructure were investigated. The phase composition and microstructure were tested by means of XRD and SEM. The results revealed that with increasing TiO2 content, the densification of the composites first increased sand then decreased and maximized at 4% TiO2 loading. This showed appropriate amount of TiO2 could contribute to the sintering of the composites due to the solid solution of TiO2 in magnesium aluminate spinel.


Author(s):  
Lydia De Brito Santos ◽  
Ana Carla Ferreira Rios ◽  
Viviane Maia Barreto Oliveira ◽  
Sônia Cristina Freitas Lemos Lopes ◽  
Taiana Silva Dantas

Most toothpastes sold in Brazil contains abrasive composition with the function of preventing the formation of spots or pigmented film and burnish the tooth surface, however, the indiscriminate use of abrasives has generated discussion regarding the effects of this component. Objective: To evaluate dentifrices sold in the city of Salvador as to its commercial presentation, regarding the inormation contained in the packages related to abrasives, in order to verify if guidelines are offered to the public to assist them in choosing those products and to the professionals when it comes to the guiding elements of the prescription. Methodology: We have analyzed 45 packages of toothpaste, randomly purchased from supermarkets in Salvador, for two years. We have observed the following: component that guides the classification of toothpaste, type and concentration of abrasive and instructions with respect to the degree of abrasiveness. Results: All trademarks contained abrasive analyzed singly or in combination; eight types of abrasives have been found: Calcium Carbonate (27%), Silica (26%), Sodium Bicarbonate, Silicon Dioxide, Titanium Dioxide, trisodium phosphate, aluminum oxide and sodium silicate. Manufacturers have associated to the dentifrices naturals extracts with the purpose to prevent the dental color change without tooth and gengival aggression caused by abrasives associations. Conclusion: Lack of guidance on packaging about the level of abrasiveness of toothpaste that can guide patients and professionals to its rational use.


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