The influence of impurities on the crystal growth kinetics according to a competitive adsorption model

• Tipo: Artigo em Revista Científica Internacional
• Data: 2006

Autores

Pedro M Martins (Autor) Outra; Fernando A Rocha (Autor) FEUP; Peter Rein (Autor) Outra

Revista

Título: Crystal Growth & Design

Vol. 6 Nº 12

Páginas: 2814-2821

ISSN: 1528-7483

Editora: American Chemical Society

Indexação

ISI Web of Knowledge - 20 Citações

ISI Web of Science

Scopus - 24 Citações

Classificação Científica

FOS: Ciências da engenharia e tecnologias > Engenharia dos materiais

CORDIS: Ciências Tecnológicas > Engenharia > Engenharia química

Outras Informações

ID Authenticus: P-004-FHB

DOI: 10.1021/cg060448x

Abstract (EN): A mathematical model describing the growth of crystals in impure solutions is presented. Evidence of competitive surface adsorption involving the crystallizing solute and impurities is discussed in terms of the adsorption isotherm in equilibrium and of the mechanism of occupation of active sites for growth. The impurity effect on crystal growth rates is characterized by the Langmuir adsorption constants and by the parameter, measuring the ability of the foreign species to move across the surface and occupy a stable position at the surface steps. Experimental growth rate data taken from the literature is used to test the proposed competitive adsorption model (CAM). The reported effects of the impurity concentration on the crystal growth rate at constant supersaturation are quantitatively described. Additionally, growth rate curves obtained in pure and impure solutions are used to investigate the influence of supersaturation on the relative growth rates. In all the examples considered, the CAM adequately describes the experimental data. An application example is given using the crystal growth rates of sucrose measured in a pilot evaporative crystallizer at different impurity concentrations. The kinetic effect of nonsucrose compounds existing in cane sugar solutions is characterized by estimating the average CAM parameters.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8