Bioactive Glass-Ceramic Foam Scaffolds from ‘Inorganic Gel Casting’ and Sinter-Crystallization
by
Hamada Elsayed 1,2
, Acacio Rincón Romero 1, Giulia Molino 3, Chiara Vitale Brovarone 3 and Enrico Bernardo 1,*
Hamada Elsayed 1,2, Acacio Rincón Romero 1, Giulia Molino 3, Chiara Vitale Brovarone 3 and Enrico Bernardo 1,*
1
Department of Industrial Engineering, University of Padova, Via Marzolo 9, 35131 Padova, Italy
2
Ceramics Department, National Research Centre, El-Bohous Street, Cairo 12622, Egypt
3
Dipartimento Scienza Applicata e Tecnologia, Politecnico di Torino, 10129 Torino, Italy
*
Author to whom correspondence should be addressed.
Materials 2018, 11(3), 349; https://doi.org/10.3390/ma11030349
Received: 11 January 2018 / Revised: 23 February 2018 / Accepted: 24 February 2018 / Published: 27 February 2018
(This article belongs to the Special Issue Bioactive Glasses 2017)
Highly porous bioactive glass-ceramic scaffolds were effectively fabricated by an inorganic gel casting technique, based on alkali activation and gelification, followed by viscous flow sintering. Glass powders, already known to yield a bioactive sintered glass-ceramic (CEL2) were dispersed in an alkaline solution, with partial dissolution of glass powders. The obtained glass suspensions underwent progressive hardening, by curing at low temperature (40 °C), owing to the formation of a C–S–H (calcium silicate hydrate) gel. As successful direct foaming was achieved by vigorous mechanical stirring of gelified suspensions, comprising also a surfactant. The developed cellular structures were later heat-treated at 900–1000 °C, to form CEL2 glass-ceramic foams, featuring an abundant total porosity (from 60% to 80%) and well-interconnected macro- and micro-sized cells. The developed foams possessed a compressive strength from 2.5 to 5 MPa, which is in the range of human trabecular bone strength. Therefore, CEL2 glass-ceramics can be proposed for bone substitutions.
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Keywords:
CEL2 glass; glass-ceramics; alkali activation; gel casting
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MDPI and ACS Style
Elsayed, H.; Rincón Romero, A.; Molino, G.; Vitale Brovarone, C.; Bernardo, E. Bioactive Glass-Ceramic Foam Scaffolds from ‘Inorganic Gel Casting’ and Sinter-Crystallization. Materials 2018, 11, 349.
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