Biomedical Engineering Reference
In-Depth Information
3
Sol-Gel Derived Glasses
for Medicine
Julian R. Jones
Department of Materials, Imperial College London, London, UK
3.1 INTRODUCTION
Glass can be made using two processing methods: the traditional
melt-quench route and the sol-gel route. In the melt-quench method,
oxides are melted together at high temperatures (above 1300
◦
C) in a
crucible and quenched in a mould or in water (Chapters 1 and 2). The
sol-gel route is a low-temperature processing route where a solution
containing the compositional components (sol) undergoes polymer-type
reactions at room temperature to form a gel. The gel is a wet inor-
ganic network, similar to a highly cross-linked short-chain inorganic
polymer, which is then dried and heated, for example to 600
◦
C, to
become a glass. The low-temperature process provides opportunities to
make porous scaffolds (Chapter 12), incorporate drugs and growth fac-
tors (Chapter 12) and allow incorporation of polymers to make hybrid
materials (Chapter 10).
The sol-gel process produces glasses with very different properties
from conventional glasses, and their potential future applications are
