The Secondary Nucleation Threshold and Crystal Growth of α-Glucose Monohydrate in Aqueous Solution

Abstract

Investigation of the secondary nucleation threshold (SNT) of R-glucose monohydrate was conducted in aqueous solutions in agitated batch systems for the temperature range 10 to 40 °C. The width of the SNT decreased as the induction time increased and was found to be temperature independent when supersaturation was based on the absolute concentration driving force. Nonnucleating seeded batch bulk crystallizations of this sugar were performed isothermally in the same temperature range as the SNT experiments, and within the SNT region to avoid nucleation. The growth kinetics were found to be linearly dependent on the supersaturation of total glucose in the system when the mutarotation reaction is not rate limiting. The growth rate constant increases with increasing temperature and follows an Arrhenius relationship with an activation energy of 50 ( 2 kJ/mol. R-Glucose monohydrate shows significant crystal growth rate dispersion (GRD). For the seeds used, the 95% range of growth rates was within a factor of 6 for seeds with a narrow particle size distribution, and 8 for seeds with a wider distribution that was used at 25 °C. The results will be used to model the significance of the mutarotation reaction on the overall crystallization rate of D-glucose in industrial crystallization.

Crystallization of alpha-lactose monohydrate in a drop-based microfluidic crystallizer

“…Growth and nucleation rates of protein and other organic crystals tend to be slower than in inorganic systems (Forsythe et al, 1994;Perry and Green, 1997), which increases the required residence time. In addition, a number of organic compounds exhibit growth rate dispersion (GRD) (Finnie et al, 1999;Srisa-nga et al, 2006), a phenomenon where crystals of the same material exposed to the same conditions grow at different rates (White and Wright, 1971). In bulk crystallization, GRD leads to a broad CSD.…”

In situ investigation of growth rates and growth rate dispersion of α-lactose monohydrate crystals

“…Growth rate dispersion, expressed as mm 2 /min 2 is a measure of how dispersed is the growth rates are from an average growth rate [23]. It is observed from the experimental results that variance in GRD increases with increasing growth rates for the four faces at all temperatures.…”

Metastable zone width and nucleation threshold of aluminium hydroxyfluoride hydrate

“…From the speciation calculations, the molarities and activities of the ions in solution could be quantified, making it possible to estimate the degree of supersaturation of AHF at varying pHs and temperatures using equation (6).…”

“…The supersaturation driving force gets to a maximum at pH 5.0 ± 0.3 after which it starts to decline. This decline is due to OH competing successfully for Al over F. Above pH 5.0, other stable phases (typically Na 3 AlF 6 and Al(OH) 3 ) are more likely to co-precipitate. It is important to note that it is unlikely to get to the maximum (pH 5.0) supersaturation practically, without spontaneous AHF precipitation.…”