Naslov
The influence of gum arabic on the precipitation of α-FeOOH in a highly alkaline medium

Autori
Opačak, Ivana ; Ristić, Mira ; Musić, Svetozar

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
MECAME 2015 Mediterranean Conference on the Applications of the Mössbauer Effect / - , 2015, 39-39

Skup
MECAME 2015 Mediterranean Conference on the Applications of the Mössbauer Effect

Mjesto i datum
Zadar, Hrvatska, 07.06.2015. - 10.06.2015

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
gum arabic ; α-FeOOH particles ; high alkaline medium ; XRD, Mössbauer spectroscopy, FT-IR spectroscopy ; SEM

Sažetak
Influence of gum arabic (GA) on the precipitation of α-FeOOH in a highly alkaline medium was investigated using XRD, 57Fe Mössbauer, FT-IR and FE-SEM. In absence of GA long α-FeOOH rods with nanosize width (~30 nm), as a single phase, were produced. The lateral aggregation of two or more α-FeOOH rods is visible. A very strong effect of GA on the precipitation of α-FeOOH in a highly alkaline medium was noticed. At a prolonged time of autoclaving time the ferrihydrite-like phase transformed to α-FeOOH and α-Fe2O3. The formation of α-Fe2O3 as the end product of this precipitation process was controlled by the dissolution/recrystallization mechanisms. The effect of GA addition to the precipitation system of Fe(ClO4)3 salt in a highly alkaline medium was assigned to the surface interactions of GA with nuclei and crystallites (particles) formed during the kinetics investigated. It was assumed that a thick layer of GA biopolymers suppressed the formation of α-FeOOH from the ferrihydrite-like phase, which is generally a fast process in the absence of GA. In such a way the conditions for nucleation and crystal growth of α-Fe2O3 are created and with a prolonged autoclaving time the reactions were shifted to the formation of α-Fe2O3 as end-product.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA