Influence of particle size on the crystallization kinetics of glasses produced from waste materials

Crystallization mechanism of glass-ceramics prepared from Ni–Cu–Co mining wastes

“…If data of Table 5 are plotted in the form of n as a function of the particle size, then an n value close to 3 is obtained for d =1 μm, and an n value close to 1 for d = 5 mm. The result obtained in this work is different to that reported by Erol et al [11] who indicated that for two glasses prepared from coal fly ashes, red mud and silica where the Fe 2 O 3 concentrations were close to those used in this work, bulk and surface crystallizations were the dominant mechanism for the coarse and fine particles, respectively. Taking into account that as the particle size increases the surface area to volume ratio decreases, then the bulk nuclei concentration is expected to be higher for larger particles whereas surface nuclei would occur predominantly on lower particle sizes.…”

“…As described in several works, iron rich glasses present a high tendency toward crystallization [5,8,9], but the presence of different types of crystals leads to simultaneous surface and internal crystallizations [10]. At the same time, for such iron rich glasses the presence of different crystallization mechanisms depending on the particle size has also been observed [5,11]. In the present work, by using DTA, HSM and dilatometric analyses, it has been shown that the presence of minor elements can affect the characteristic temperatures of an iron-rich glass and mainly their crystallization temperatures.…”

45S5 bioactive glass reactivity by dynamic vapour sorption

“…FTIR spectroscopy after vapour sorption showed the formation of O-H groups, which remained even after conditioning at 0% RH for 24 h. XRD diffractograms also indicated changes in the amorphous/crystalline structure of the BGs after vapour sorption. Furthermore, these peaks appeared to be sharper for BG-1 particles which suggested greater extent of crystallization, and thus potentially more rapid surface transformation [27,33].…”

Influence of Fe 2 O 3 on non-isothermal crystallization kinetics and microstructure of lithium titanium phosphate glass-ceramics

“…The activation energy for crystallization was calculated according to the Marotta, the Augis-Bennett and the modified Kissinger methods. The Avrami exponent was also measured through the Ozawa and Marotta methods [21][22][23][24][25][26][27].…”

“…The Avrami exponent (n) can be extracted from the Marotta and the Ozawa equations, respectively [24][25][26][27]: …”