Naslov
On the real significance of the "Induction period" of zeolite crystallization

Autori
Subotić, Boris ; Bronić, Josip ; Antonić, Tatjana

Vrsta, podvrsta i kategorija rada
Radovi u zbornicima skupova, cjeloviti rad (in extenso), znanstveni

Izvornik
Proceedings of the 12th International Zeolite Conference / Treacy, M. M. J. ; Marcus, B. K. ; Bisher, M. E. ; Higgins, J. B. - Warrendale (PA) : Materials Research Society, 1999, 2057-2064

Skup
12th International Zeolite Conference

Mjesto i datum
Baltimore (MD), Sjedinjene Američke Države, 05.07.1998. - 10.07.1998

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
Induction period of zeolite crystallization; Activation energy of gel dissolution/zeolite nucleation and crystal growth

Sažetak
An analysis of the relationships between ln (1/t_i) vs. 1/T, ln (df_z/dt_c) vs. 1/T and lnK vs. 1/T (t_i is the "induction period" of crystallization, f_z is the fraction of zeolite crystallized up to time of crystallization, t_c, K is the rate constant of the crystallization process and T is absolute temperature) was made for zeolite crystallization at different temperatures, simulated by population balance method using appropriate mechanisms of gel dissolution, nucleation and crystal growth. The analysis have shown that the slope, S_1, of the ln (1/t_i) vs. 1/T straight line is the same as the slope, S_2, of the ln (df_z/dt_c) vs. 1/T straight line, i.e., that the activation energy calculated from the slope S_1 corresponds to the activation energy, E_c, of the entire crystallization process, and not to the activation energy, E_n of nucleation. The same relations are valid for any crystallization time (ln K vs. 1/T plots), thus indicating that the processes occurring during the "induction period" are qualitatively the same as the processes that occur during the "growth period".

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA