title: [Preparation of nanometer powders of dental alumina ceramics].
abstract: OBJECTIVE
  The purpose of this study was to explore the preparation method of nanometer powders of dental alumina ceramics.
  
  
  METHODS
  The effects of concentration of inorganic precursors, pH value, calcination temperature and ageing time on the synthesizing process, phase composition and microstructure of the materials were studied. Aluminium nitrate with concentrations of 0.03 mol/L, 0.05 mol/L, 0.1 mol/L and 0.2 mol/L were used as inorganic precursors to prepare alumina powders via sol-gel method. Ammonia water was added into the solutions to adjust the pH values to 5, 9 and 11. The dried gel was then calcined under different temperatures, from 950 degrees C to 1200 degrees C. The prepared alumina powders were studied by using X-ray diffraction (XRD), and scanning electron microscope (SEM).
  
  
  RESULTS
  The alumina powder which was prepared with 0.1 mol/L aluminium nitrate, pH 9, and calcined at 1200 degrees C for 10 min showed good physical characteristics. The diameter of final powder was about 70 nm.
  
  
  CONCLUSIONS
  With the proper preparation condition, weakly agglomerated powders of alumina in nanometer particle size could be obtained.
authors.affiliation: College of Stomatology, West China University of Medical Sciences.
authors.forename: Ke
authors.initials: K
authors.lastname: Zhao
authors.forename: Yonglie
authors.initials: Y
authors.lastname: Chao
authors.forename: Shiyuan
authors.initials: S
authors.lastname: Yang
authors.forename: Junxia
authors.initials: J
authors.lastname: Wang
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D001672:Biocompatible Materials / Q000138:chemical synthesis; D002516:Ceramics / Q000138:chemical synthesis*; D003764:Dental Materials / Q000138:chemical synthesis; D003776:Dental Porcelain / Q000737:chemistry*; D005782:Gels; D006863:Hydrogen-Ion Concentration; D036103:Nanotechnology; D010316:Particle Size; D011208:Powders
chemical_list: D001672:Biocompatible Materials; D003764:Dental Materials; D005782:Gels; D011208:Powders; D003776:Dental Porcelain; D000537:Aluminum Oxide