STRUCTURAL INVESTIGATIONS OF SIO2-CONTAINING PHOSPHATE-GLASSES

The incorporation of SiO2 into phosphate glasses is interesting in vie w of the development of phosphatic biomaterials. The present investiga tion is concerned with the incorporation of SiO2 into phosphate base g lasses possessing different phosphate structures. Due to their structu ral characteristics, they can be classified into three groups: glasses with long phosphate chains or rings formed by Q(2) phosphate structur al groups, glasses with shorter phosphate chains formed by Q(2) and Q( 1) groups and glasses with phosphate invert glass structure, possessin g ortho(Q(0))- and pyrophosphate groups (two Q(1) groups) exclusively. The structures of these glasses in dependence on the incorporated sil ica were investigated by transmission electron microscopy and by P-31 MAS NMR. Thr principles of incorporation are discussed.