Turner Legacy Symposium
Chemical Nanoheterogeneity in Glasses: Origin, Nature and Implications
article posted 04 Feb 2016
"A silicate glass might be conceived of as a sponge of silica containing silicates or their dissociation products as the filling medium."
William Ernest Stephen Turner (1925)
This highly perceptive comment by Turner at the first Symposium on the Constitution of Glass
, organised by the Society of
Technology in 1925, reflected the then current consensus that the structures of glasses having more than one component are
chemically nanoheterogeneous. However, whereas the concept of chemical nanoheterogeneity continued to be accepted in
Russia, in the West it was replaced by that of a statistically-homogeneous structure, as predicted by the random network theory,
only to be readopted during the closing decades of the 20th Century.
As a result, it is not always appreciated that the presence
of chemical nanoheterogeneity in single-phase glasses has extremely important consequences for modern glass science and
technology, and so the objective of the present symposium (part of the SGT Centenary Conference) is to consider both the origin and nature of chemical nanoheterogeneity
in the broadest sense, including its relationship to well documented phenomena, such as:
Rui M. Almeida
The atomic composition of silicate glass surfaces
New twists on the path to understanding the glass transition and the ultimate fate of supercooling liquids
Delia S. Brauer
The role of fluoride in the chemical nanoheterogeneity of phospho-silicate glasses
Nanohoterogeneity in glasses: apoint of view from cations
Energentic implication of chemical nanoheterogeneity in glasses
Nanophase formation in the process of nucleation and crystallisation of glass ceramics
Interactions of glass with the living world: impact of nanoheterogeneity
Phase seperation in melting gels
Dynamical heterogeneties and relaxation in glass
From preferential bonding via clustering to phase-separated borosilicate glasses – a multi spectroscopic approach
Homogeneous and inhomogeneous modifier cation distributions in oxide glases from molecular dynamics
Probing cystallization of a fluoro-apatite - mullite system using neutron diffraction
Carlo G Pantano
The Heterogeneity of Glass Surfaces Revealed by Temperature Programmed Desorption
The roles of nano-scale heterogeneity fluctuations on the properties of optical composites
Precolation, phase separation and crystallisation
Role of Water in Silica Glass: Composition Fluctuation and Surface Stress Relaxation.
Recent Advances in the Chemical Strengthening of Glass
The thermodyamic origin of compositional nanoheterogeneity in glasses
Density fluctuations in single- component glasses
The effect of nanoheterogeneities (liquid-liquid phase separation) on crystal nucleation in glass-forming silicate liquids
- Melting & Thermal History - for example, the effects of atmosphere, volatilisation and secondary processing.
- Crystallisation/Devitrification - for example, the formation of crystalline nuclei, and the nature of the (unstable) thermodynamic fluctuations that give rise to spinodal decomposition.
- Phase Separation - for example, sodium borosilicate glasses, and the preparation of vycor glass.
- Surfaces - for example, structure of glass surfaces, and its influence on properties such as chemical durability, volume relaxation, ion-exchange, and mechanical strength (the origin/formation of Griffiths flaws).