Effect of particle size and Al substitution

As discussed further in Chapter 9, energy relationships are also influenced by surface properties, which must be taken into account once the crystals become smaller than ca. 1pm (Tab. 8.5). Langmuir (1971) calculated AGr(298) in liquid water as a function of particle size, using differential heat of solution values (as a function of 

Left at various temperatures and constant water activity of 1.0. Right at various water activities and a constant temperature of 25 °C (Trolard, Tardy, 1987 with permission). 

Langmuir s approach, therefore, appears to require further development before it can be used as a predictive tool. Long term experiments to test whether this transformation occurs have not been carried out. 

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