title: Spheroidization of glass powders for glass ionomer cements.
abstract: Commercial angular glass powders were spheroidized using both the flame spraying and inductively coupled radio frequency plasma spraying techniques. Spherical powders with different particle size distributions were obtained after spheroidization. The effects of spherical glass powders on the mechanical properties of glass ionomer cements (GICs) were investigated. Results showed that the particle size distribution of the glass powders had a significant influence on the mechanical properties of GICs. Powders with a bimodal particle size distribution ensured a high packing density of glass ionomer cements, giving relatively high mechanical properties of GICs. GICs prepared by flame-spheroidized powders showed low strength values due to the loss of fine particles during flame spraying, leading to a low packing density and few metal ions reacting with polyacrylic acid to form cross-linking. GICs prepared by the nano-sized powders showed low strength because of the low bulk density of the nano-sized powders and hence low powder/liquid ratio of GICs.
authors.affiliation: School of Materials Engineering, Nanyang Technological University, Singapore. mywgu@ntu.edu.sg
authors.forename: Y W
authors.initials: YW
authors.lastname: Gu
authors.forename: A U J
authors.initials: AU
authors.lastname: Yap
authors.forename: P
authors.initials: P
authors.lastname: Cheang
authors.forename: R
authors.initials: R
authors.lastname: Kumar
mesh_terms: D019245:Compressive Strength; D003460:Crystallization / Q000379:methods*; D005898:Glass / Q000737:chemistry; D005899:Glass Ionomer Cements / Q000737:chemistry*; D006244:Hardness; D006358:Hot Temperature; D008422:Materials Testing; D008863:Microspheres; D008968:Molecular Conformation; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure*; D010316:Particle Size; D011208:Powders; D013499:Surface Properties; D013718:Tensile Strength
chemical_list: D005899:Glass Ionomer Cements; D011208:Powders