Publikace detail

Reaction/crystallization kinetics studied via in situ XRD: experimental conditions versus methods of kinetic analysis

Autoři: Svoboda Roman

Rok: 2019

Druh publikace: článek v odborném periodiku

Název zdroje: Philosophical Magazine

Název nakladatele: Taylor & Francis Ltd.

Místo vydání: Abingdon

Strana od-do: 2941-2956

Tituly:

Jazyk	Název	Abstrakt	Klíčová slova
cze	Reakční a krystalizační kinetika studovaná pomocí in-situ XRD: experimentální podmínky versus metody kinetické analýzy	Teoreticky simulovaná data byla použita pro vývoj chyb asocviovaných s běžným vyhodnocením in-situ neizotermních XRD dat v případě teplotního programu sestávajícího ze střídání neizotermního ohřevu a izotermních kroků, kdy je snímán difrakční vzorec.	in-situ XRD; kinetická analýza; krystalizace; teoretická simulace; KMJMA model
eng	Reaction/crystallization kinetics studied via in situ XRD: experimental conditions versus methods of kinetic analysis	Theoretically simulated kinetic data were used to evaluate the errors associated with the common issue of evaluating the in situ non-isothermal X-ray diffraction data, where the complex multi-step temperature program (alternating the non-isothermal heating steps with isothermal steps during which the diffraction patterns are collected) is for the purposes of evaluation replaced by a simple non-isothermal heating performed at the reduced/effective heating rate. The kinetic analysis has shown that, in general, best results are provided by the non-linear optimisation methods simultaneously evaluating the data-curves obtained for all the different heating rates. For the nucleation growth (KMJMA) kinetics the distortive influence of the temperature program parameters increases as follows: heating rate during non-isothermal segments < duration of the isothermal segment < temperature interval between the isothermal segments. The non-optimisation methods of kinetic analysis (integral isoconversional methods for evaluation of activation energy E and master plots for determining the appropriate kinetic model) were found to perform inaccurately, with large degree of randomness based on the selection of starting temperature, and are not recommended for evaluation of the in situ XRD data - the only exception seem to be the differential isoconversional methods that provided accurate E values. Generalisation of the present conclusions for all KMJMA processes is suggested and discussed.	In situ XRD; kinetic analysis; crystallization; KMJMA model; theoretical simulations

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