CuO nanocrystal formation during sintering of Cu-doped bioactive silicate glass powder surfaces

Blaeß C, Boccaccini AR, Müller R (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Ceramics International Elsevier

DOI: 10.1016/j.ceramint.2026.03.017

Abstract

CuO nanocrystals were found to grow on polished, fractured, and glass powder particle surfaces of the copper-doped bioactive glass BG F3-Cu (44.8 SiO2–2.5 P2O3–35.5 CaO–6.6 Na2O–6.6 K2O–3 CaF2–1 CuO; mol%). Our results indicate that this CuO formation is driven by an inhibited Cu+/Cu2+ redox equilibrium. Since Cu2+ (CuO) is unstable during melting, a Cu+ (Cu2O) excess is frozen during cooling. Due to the limited oxygen availability, Cu + diffuses to the surface to get oxidized to Cu2+. Such oxidation, however, also occurs close beneath the melt surface during casting. As this reduces the CuO formation driving force, no CuO was found on the as-cast glass surface. The large low-temperature driving force of Cu oxidation also explains why CuO nanocrystals can easily grow during prolonged annealing well below the onset of the dominating surface crystallization of combeite during heating at 10 K/min. The minor influence of CuO surface crystal formation on sintering and overall crystallization allows for its control largely independent of the achievable densification and phase composition of the sintered BG compacts.

Authors with CRIS profile

Aldo Boccaccini Lehrstuhl für Werkstoffwissenschaften (Biomaterialien)

Involved external institutions

Universidade Federal de São Carlos (UFSCar) / Federal University of São Carlos BR Brazil (BR) Bundesanstalt für Materialforschung und -prüfung (BAM) DE Germany (DE)

How to cite

APA:

Blaeß, C., Boccaccini, A.R., & Müller, R. (2026). CuO nanocrystal formation during sintering of Cu-doped bioactive silicate glass powder surfaces. Ceramics International. https://doi.org/10.1016/j.ceramint.2026.03.017

MLA:

Blaeß, Carsten, Aldo R. Boccaccini, and Ralf Müller. "CuO nanocrystal formation during sintering of Cu-doped bioactive silicate glass powder surfaces." Ceramics International (2026).

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