الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 32 |  |  |
| | | from | 32 | | |
Abstract
This thesis comprises the preparation of some selected bioglasses and the investigation of their chemical behaviour towards the action of several leaching solutions including acidic HCI and alkaline NaOJ-1, Tris and simulated body fluid together with each of its individual constituents.
The thesis also includes detailed infrared absorption studies of the prepard bioglasses before and after being immersed in each of the leaching solutions.
All the bioglasses were prepared from chemically pure raw materials. Melting was carried in platinum 2% rhodium crucibles in an electric furnace at temperatures ranged from 1400 to 1450’C. The time of melting was extended to 3 hours to achieve homogeneity. The melts were carefully annealed after pouring in a muffle furnace at 50-SOO)C. The muffle was left to cool to room temperature at a rate of 30’C/hour.
The measurements of the corrosion weight loss were carried out using either glass grains (grain size 0.3-0.6 mm) or glass powders (grain size < 0.3 mm). The study includes the immersion of 0.5 gm of the specified grain placed in a sintered glass crucible G 4 type in the leaching solution at 95’C for I hour. The weight loss percentage was calculated for each bioglass and for each specified immersed solution.
The experimental corrosion results revealed that the weight loss varied with the composition of the bioglass and with the type of the immersed solution. Sodium phosphate solution (0.5 or 1.0 M) was found to heavily corrode almost all the bioglasses studied while HCI solution