Ion distribution in matrix parts of glass-polyalkenoate cement by SIMS.

The microstructure of the set glass-polyalkenoate cement has not been undertaken beyond a study where an Electron Probe Micro Analyser was used. The purpose of this investigation was to determine the ion distribution in matrix parts of the set cement by means of Secondary Ion Mass Spectrometry (SIMS). Among the techniques for surface and microscopic analysis, SIMS is said to be the one with the highest sensitivity. O2+ ions were used as the beam probe to detect silicon, aluminum, calcium, sodium, and carbon. The scanning images showed a clear difference among these elements in their distribution. A large amount of aluminum was found throughout the matrix area, with only a slight concentration gradient, while silicon appeared to be concentrated on the surface of the undissolved glass core. The distribution pattern of calcium was not as clear as that shown by aluminum and silicon. A comparatively higher content of carbon was found closer to the glass surface. These results indicate that aluminum plays an essential role in the setting of the matrix and the surface of the glass dissolved by acrylic acid and changed into the siliceous gel.