Understanding the structural drivers governing glass-water interactions in borosilicate based model bioactive glasses

Area of Science:

• Materials Science
• Biomaterials Engineering
• Chemical Engineering

Background:

• Borate and borosilicate bioactive glasses offer faster degradation rates compared to traditional silicate glasses.
• Current design of these glasses relies heavily on a "trial-and-error" approach due to limited understanding of their aqueous corrosion.
• There's a growing need for a "materials-by-design" approach for advanced bioactive glass formulations.

Purpose of the Study:

• To investigate the impact of thermal history on the molecular structure and dissolution behavior of borosilicate bioactive glasses.
• To address experimental challenges in understanding the degradation mechanisms of boron-containing bioactive glasses.
• To propose a refined methodology for studying bioactive glass dissolution.

Main Methods:

• Studied a simplified borosilicate based model melt-quenched bioactive glass system.
• Investigated the effect of quenching methodology on glass structure and dissolution rates.
• Recommended the use of surface area to volume (SA/V) ratio for dissolution studies.

Main Results:

• The thermal history and quenching method significantly influence the molecular structure of the glass.
• Dissolution rates varied by 1.5×-3× based on induced structural changes from thermal history.
• The SA/V approach is recommended over the mass-to-volume approach for accurate dissolution assessment.

Conclusions:

• A deeper understanding of degradation reaction sequences and structural drivers is crucial for designing third-generation bioactive glasses.
• The proposed experimental approach enhances understanding of composition-structure-property relationships in borosilicate bioactive glasses.
• This research facilitates the development of bioactive glasses with tailored dissolution rates for specific medical applications.