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Effect of nitridation on the aqueous dissolution of Na2O–K2O–CaO–P2O5 metaphosphate glasses

Paper ID Volume ID Publish Year Pages File Format Full-Text
1371 82 2011 6 PDF Available
Title
Effect of nitridation on the aqueous dissolution of Na2O–K2O–CaO–P2O5 metaphosphate glasses
Abstract

The use of oxynitride glasses is presented as an alternative for the preparation of bioresorbable phosphate glasses with a controlled dissolution rate. This work describes the design of oxynitride phosphate glasses within the systems of composition (50 – x)Na2O·xCaO·50P2O5 and (25 – (x/2))Na2O·(25 – (x/2))K2O·xCaO·50P2O5 (x = 5, 10, 15, 20 mol.%) throughout the processing parameters of the ammonolysis reaction and the glass composition. Mixed-alkali sodium–potassium phosphate glasses with low CaO contents present the best characteristics for nitridation. The dissolution rate has been determined by immersion of glass samples in water, at constant temperature of 37 °C, and has been discussed as a function of both modifiers composition and nitrogen content incorporated in the glasses through ammonolysis. All oxynitride glass compositions dissolve congruently and their dissolution rate decreases by more than three orders of magnitude for the highest nitrogen contents. However, it has been demonstrated that nitrogen contents as low as 2–3 wt.% (i.e. a 0.2 N/P ratio) are sufficient to decrease the dissolution rate by one order of magnitude with respect to the pure oxide glasses. Novel oxynitride phosphate glasses with a controlled and congruent dissolution are proposed for future applications in biodegradable composite materials, tissue engineering or host matrices for the controlled release of drugs.

Keywords
Phosphate glasses; Bioresorbable glasses; Oxynitride glasses; Controlled release; Nitridation
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Effect of nitridation on the aqueous dissolution of Na2O–K2O–CaO–P2O5 metaphosphate glasses
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Publisher
Database: Elsevier - ScienceDirect
Journal: Acta Biomaterialia - Volume 7, Issue 6, June 2011, Pages 2631–2636
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us