Calcium alginate beads prepared with a dropping device were cross-linked with epichlorohydrin in order to obtain selective ion exchangers from cross-linked natural polymers. The alginate was first activated with alcoholic soda to convert OH groups into alcoholates. This treatment also leads to considerable dehydration, and the consequent shrinkage of particle size was employed to evaluate the action of NaOH. This paper reports the shrinking kinetics as a function of temperature (2-38°C), initial bead diameter, and reagent concentration. A small number of particles were photographed during reaction in stagnant fluid. Their diameters were then measured and suitably classified. It was found that the shrinkage is dependent on mass transfer, and that its rate is directly proportional to the water concentration gradient on the surface of the particles, and inversely proportional to their initial diameter, if this is not more than 3 mm.
Shrinking kinetics of calcium alginate beads in alcoholic soda / Ferrero, Franco; Campagna, P; Piccinini, N.. - In: CHEMICAL ENGINEERING COMMUNICATIONS. - ISSN 0098-6445. - STAMPA. - 15:1-4(1982), pp. 197-206. [10.1080/00986448208911069]
Shrinking kinetics of calcium alginate beads in alcoholic soda
FERRERO, Franco;
1982
Abstract
Calcium alginate beads prepared with a dropping device were cross-linked with epichlorohydrin in order to obtain selective ion exchangers from cross-linked natural polymers. The alginate was first activated with alcoholic soda to convert OH groups into alcoholates. This treatment also leads to considerable dehydration, and the consequent shrinkage of particle size was employed to evaluate the action of NaOH. This paper reports the shrinking kinetics as a function of temperature (2-38°C), initial bead diameter, and reagent concentration. A small number of particles were photographed during reaction in stagnant fluid. Their diameters were then measured and suitably classified. It was found that the shrinkage is dependent on mass transfer, and that its rate is directly proportional to the water concentration gradient on the surface of the particles, and inversely proportional to their initial diameter, if this is not more than 3 mm.File | Dimensione | Formato | |
---|---|---|---|
1982 ChemEngComm Shrinking kinetics.pdf
accesso riservato
Tipologia:
2a Post-print versione editoriale / Version of Record
Licenza:
Non Pubblico - Accesso privato/ristretto
Dimensione
329.12 kB
Formato
Adobe PDF
|
329.12 kB | Adobe PDF | Visualizza/Apri Richiedi una copia |
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
https://hdl.handle.net/11583/1651662