Further evidence against the alleged failure of the classical nucleation theory below the glass transition range

Abstract

We collected a plethora of new data to test the hypothesis that the failure of the Classical Nucleation Theory (CNT) below the glass transition range is just an experimental artifact. Since reaching the steady‐state nucleation regime takes a significant time for treatments below the glass transition temperature, data collected in this temperature range tend not to have reached a steady state. Because of this potential problem, we examined the CNT using new experimental data for three stoichiometric silicate glasses: Li2Si2O5, BaSi2O5, and Na4CaSi3O9. We also measured the equilibrium viscosity for the studied glass batches and used it as a proxy for the effective diffusion coefficient. The analysis was conducted by applying a steady‐state criterion and evaluating the error propagation throughout all calculations. Using this rigorous procedure, we have not observed the alleged CNT failure. Our comprehensive results support recent studies questioning this possible CNT failure helping solve a longstanding problem in glass science.

A new perspective for nucleation and nanocrystallization from interfacial energy and nanoscale composition fluctuations in glasses

“…The temperature dependence (450°C–600°C) of r * and Δ G * in Li 2 O–2SiO 2 glass/SCL is shown in Figure 8, indicating that both parameters increase with increasing temperature. That is, for the formation of nanocrystals having radius as possible as small, the nucleation should be carried out at low temperatures close to the glass transition temperature, that is, T g = 455°C 16 …”

“…Numerous studies on the nucleation mechanism and kinetics in oxide SCLs have been reported so far. In particular, the homogeneous nucleation kinetics by thermodynamic approach based on the classical nucleation theory (CNT) for some stoichiometric SiO 2 ‐based glasses/SCLs such as lithium disilicate Li 2 O–2SiO 2 and Na 2 O–2CaO–3SiO 2 have been studied in detail 4,11–16 . In the CNT approach, one of the most crucial issues is to evaluate the interfacial energy ( γ ) at the SCL–nucleus interface, because the γ value itself in oxide glasses/SCLs has not been measured directly (independently) from experiments.…”

Crystallization in a soda–lime‐silicate glass after high pressure

“…Lastly, recent works are proposing a new theory to study nucleation, relating the relaxation of the material with the time needed to reach steady‐state nucleation, where it is proposed that a glass will only reach its steady state corresponding to the fully relaxed supercool liquid state 14–19 . Crystal nucleation happens concomitantly with the relaxation process toward the SCL, strongly affecting the nucleation rate measured at temperatures below T max , taking a very long time to reach steady‐state nucleation 15 .…”

“…12 Lastly, recent works are proposing a new theory to study nucleation, relating the relaxation of the material with the time needed to reach steady-state nucleation, where it is proposed that a glass will only reach its steady state corresponding to the fully relaxed supercool liquid state. [14][15][16][17][18][19] Crystal nucleation happens concomitantly with the relaxation process toward the SCL, strongly affecting the nucleation rate measured at temperatures below T max , taking a very long time to reach steady-state nucleation. 15 Finally, on a similar note, Abyzov et al showed that stresses present in the material reduce the thermodynamic driving force for crystallization and thus increase the nucleation barrier, causing a decrease in the nucleation rate.…”

Carbon Black Nanoparticle/Polydopamine-Coated Core-Spun Yarns for Flexible Strain Sensors

“…However, the complicated structure of the textile usually hinders the distribution of the fillers into/onto the fabric. Neither the classical melting mixing method , nor the in situ process − for producing conductive composites is applicable for strain sensors based on textile matrices. Therefore, dip-coating processes with chemical solvents are often used. ,− …”