Mo-Sci Health Care has extensive experience in the manufacture of biocompatible glasses. Bactifree is a silver-containing clear or colored glass powder that is free-flowing and hydration resistant. Compositions are available that allow for a wide range of dissolution rates giving an almost unlimited control rate. Bactifree has many applications, which include media for filters and bacterial growth inhibitors in cosmetics.
Description
The dissolution rate and solubility of the powder in aqueous liquids depend upon the particle size and the specific glass composition and can be controlled to cover a wide range—from a few minutes to months to dissolve. During dissolution, silver ions are released from the glass and go into solution along with the other constituents in the glass. The glass is non-toxic but care should be taken to prevent it from being inhaled or coming into contact with eyes.
Composition and Properties
Nominal Composition (wt%):
Ag2O
1-30%
Li2O, Na2O, K2O
0-12%
Al2O3
0-5%
P2O5
0-70%
B2O3
40-80%
Properties for Bactifree glass:
Specific gravity 2.1-3.4 g/cm3
Refractive index (nD) 1.55-1.9
Softening Temp (Ts) 325-500°C
Exp. Coeff. 7-15 x 10-7 (30-300°C)
Solubility (variable)
Particle Size 10-200 microns
In acidic liquids the pH may increase by varying amounts as the glass slowly dissolves. In basic or neutral liquids the pH remains constant or decreases to neutral.
The product can also be supplied as microspheres in diameter ranging from 10-150 microns. Microspheres are more free-flowing and have a "smoother" feel than crushed powders.
Bactifree can also be supplied in compositions that release a wide range of elements such as selected alkalies, alkaline earths and transition metals.
Mo-Sci Health Care 
