boron-oxide and disilver-oxide

Quaternary Ag(2)O-CaO-Bi(2)O(3)-B(2)O(3) glasses and glassceramics are investigated with regard to release behaviour and local structure. The dissolution behaviour in water and physiological serum shows that the cations are released rapidly or gradually and points out a multi-step process, generally characterised by higher rates in water than in physiological serum. The structural effect of silver addition to bismuth-borate glasses is observed from infrared spectroscopic data. The antibacterial activity of the investigated samples was tested on six bacterial media.

Topics: Anti-Bacterial Agents; Bacteria; Biocompatible Materials; Bismuth; Boron Compounds; Calcium Compounds; Ceramics; Glass; Humans; In Vitro Techniques; Materials Testing; Molecular Structure; Oxides; Silver Compounds; Spectrophotometry, Infrared; Spectrum Analysis; X-Rays

The density of states of Ag(2)O--B(2)O(3) glasses has been calculated by using a modified scale-transformed energy space sampling algorithm. This algorithm combines the scale-transformed energy space sampling algorithm and the Wang-Landau method. It is shown how the two algorithms can be combined to improve the efficiency of calculation. The thermodynamic properties, in particular the specific heat C(V), of the above-mentioned glass system is studied. At temperatures above 80 K, the value of specific heat C(v) is close to 22 J/mol/K. At low temperatures, the deviations of C(v) from a T(3) behavior are discernible, that is, C(v)/T(3) exhibits a hump at T = 7 K, which is in good agreement with the reported experimental behavior.

Topics: Algorithms; Boron Compounds; Computer Simulation; Glass; Hot Temperature; Monte Carlo Method; Oxides; Polymers; Silver Compounds; Temperature; Thermodynamics