Phosphate-based glasses structure

The D-HMQC technique also participates to the reinvestigation of boro-phosphate-based glasses structure in 2011 [48,49]. These glasses, investigated for their high thermal stabiHty and for their ionic conductivity when alkali ions are inserted in the formulation, have been studied by CP-MAS in 2005 [50]. The first ever reported 2D correlation map clearly shows... 

Metaphosphate glasses are of particular interest in the development of glass-ceramics and glass-ceramic fibers (Griffith 1995) by the controlled crystallization of phosphate base glasses. These glasses are composed of (PO ) tetrahedra chains. In chemical terms, these structural units must be called condensed phosphates. 

Eirst systematic study of phosphate bonding and phosphate cements Kirsanov reaction discovered Identification of UDP glucose Formulated rules for base composition of DNA Advanced theories of phosphate glass structure First NMR spectra of P compounds published Showed (with P) that viruses work by injecting their DNA or RNA into cells under attack... 

In 2013, the D-HMQC technique has been involved in the structural characterisation of vanado-phosphate-based system within the 50Na2O-3cV2O5-(50 — 3c)P20s composition line [53]. These glasses have already been investigated by Raman and ID P and NMR spectroscopies [54,55]. The results suggest that the network was built by interconnected vanadate and phosphate polyhedra but no direct evidence about the presence of P—O—V bond was available. D-HMQC experiment was applied... 

A Cameron-Plint friction machine generated tribofilms with two-layer structure a zinc polyphosphate thermal film overlying a mixed short-chain phosphate glass, containing iron sulfide precipitates. A tribochemical reaction between the zinc polyphosphate and the iron oxides species is proposed on the basis of the hard and soft acid and base HSAB principle (Martin, 1999 Martin et al., 2001). 

Phosphate glasses have also been investigated as nuclear waste forms. These are typically made with nonvolatile, high-valent metals such as Fe, Zr, lanthanides, or Th, sometimes with additions of lead to promote glass formation, for example, Fe-Pb-phosphate glasses. Crystalline waste forms based on the NaZr2(P04)3 NASICON structure (see Section 5.2.1) have also been studied as these can exchange Na for Cs, which is difficult to immobilize. 

A number of studies of radiation effects on phosphate glasses have been conducted because of the variety of technological applications for phosphate glasses. There are no studies of phosphate glasses that have been doped with actinides. Based on present studies, which mainly emphasize the effect of ionizing radiation on the structure of phosphate glass, one must anticipate important effects associated with ionization caused by the alpha-particle. 

---