How to measure supersaturation?

Löffelmann, Michael; Mersmann, Alfons

doi:10.1016/s0009-2509(02)00347-0

Cited by 33 publications

(13 citation statements)

References 4 publications

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“…As reviewed by Löffelmann and Mersmann, supersaturation is the most decisive parameter for crystallization processes including crystal growth, agglomeration and aggregation, and primary and secondary nucleation. It therefore influences crystal-product qualities such as crystal morphology, purity, specific surface area, and crystal size distribution.…”

Section: Introduction and Theorymentioning

confidence: 99%

Manipulating Single Microdroplets of NaCl Solutions: Solvent Dissolution, Microcrystallization, and Crystal Morphology

Utoft

Kinoshita

Bitterfield³

2018

Langmuir

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A new "three-micropipette manipulation technique" for forming, dehydrating, crystallizing, and resolvating nanograms of salt material has been developed to study supersaturated single microdroplets and microcrystals. This is the first report of studies that have measured in situ both supersaturation (as homogeneous nucleation) and saturation (as microcrystal redissolution) for single microdroplets of NaCl solution using the micropipette technique. This work reports a measure of the critical supersaturation concentration for homogeneous nucleation of NaCl (10.3 ± 0.3 M) at a supersaturation fraction of S = 1.9, the saturation concentration of NaCl in aqueous solution as measured with nanograms of material (5.5 ± 0.1 M), the diffusion coefficient for water in octanol, D = (1.96 ± 0.10) × 10 cm/s, and the effect of the solvent's activity on dissolution kinetics. It is further shown that the same Epstein-Plesset (EP) model, which was originally developed for diffusion-controlled dissolution and uptake of gas, and successfully applied to liquid-in-liquid dissolution, can now also be applied to describe the diffusion-controlled uptake of water from a water-saturated environment using the extended activity-based model of Bitterfield et al. This aspect of the EP model has not previously been tested using single microdroplets. Finally, it is also reported how the water dissolution rate, rate of NaCl concentration change, resulting crystal structure, and the time frame of initial crystal growth are affected by changing the bathing medium from octanol to decane. A much slower loss of water-solvent and concomitant slower up-concentration of the NaCl solute resulted in a lower tendency to nucleate and slower crystal growth because much less excess material was available at the onset of nucleation in the decane system as compared to the octanol system. Thus, the crystal structure is reported to be dendritic for NaCl solution microdroplets dissolving rapidly and nucleating violently in octanol, while they are formed as single cubic crystals in a gentler way for solution-dissolution in decane. These new techniques and analyses can now also be used for any other system where all relevant parameters are known. An example of this is control of drug/hydrogel/emulsion particle size change due to solvent uptake.

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Section: Introduction and Theorymentioning

confidence: 99%

Manipulating Single Microdroplets of NaCl Solutions: Solvent Dissolution, Microcrystallization, and Crystal Morphology

Utoft

Kinoshita

Bitterfield³

2018

Langmuir

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“…Measuring the extent, or degree of supersaturation (DS) for transient systems is problematic. Numerous methods have been previously developed to measure the DS in traditional supersaturated systems including titration, refractometry, particle analysis, viscosity testing and attenuated total reflection Fourier infrared spectroscopy (ATR‐FTIR), but most of these techniques are intrusive and may interfere with the crystallisation process 12. As a result the DS is typically determined indirectly by comparison of mass transfer rate from a saturated solution through a barrier membrane, for example cellulose,13 silicone14 or skin15, 16 to a supersaturated system.…”

Section: Introductionmentioning

confidence: 99%

Determining Degree of Saturation after Application of Transiently Supersaturated Metered Dose Aerosols for Topical Delivery of Corticosteroids

Jones

Reid

Brown

2009

Journal of Pharmaceutical Sciences

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“…The addition method and initial concentration of the reactant have a great impact on supersaturation, hence, on the quality of the produced crystals [32]. This is better seen by referring to Eq.…”

Section: Supersaturation Effectmentioning

confidence: 99%

Precipitation of nesquehonite from homogeneous supersaturated solutions

Cheng

2009

Cryst. Res. Technol.

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The homogeneous (unseeded) precipitation of nesquehonite (MgCO 3 ·3H 2 O) was studied over the temperature range of 10-40 °C. Precipitation was triggered by the supersaturation created by mixing MgCl 2 solution (0.5-1.5 M) with Na 2 CO 3 solution in the same concentration range. The Meissner's method was adopted in the calculation of supersaturations during the MgCl 2 -Na 2 CO 3 reaction to monitor the precipitation. Solids were identified using X-ray diffraction (XRD) analysis and scanning electron microscope (SEM) images. In the temperature range of 10-40 °C, MgCO 3 ·3H 2 O with needle-like or gel-like morphology was precipitated. It was seen that the length, width and surface smoothness of the particles changed with reaction temperature and supersaturation. The supersaturation (S) was in the range of 1.09-58.68 during titration of Na 2 CO 3 solution. The dimension of the crystals increased with longer addition time (or lower initial concentration of reactant) at the same temperature. Slower addition via titration of 2 h followed by 2 h of equilibration at 40 °C proved successful in producing well developed needle-like MgCO 3 ·3H 2 O crystals of 30-50 µm long and 3-6 µm wide. MgCO 3 ·3H 2 O obtained were calcined to produce highly pure magnesium oxide (MgO) at 800 °C. The morphology of MgO was similar to that of their corresponding precursors.

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How to measure supersaturation?

Cited by 33 publications

References 4 publications

Manipulating Single Microdroplets of NaCl Solutions: Solvent Dissolution, Microcrystallization, and Crystal Morphology

Manipulating Single Microdroplets of NaCl Solutions: Solvent Dissolution, Microcrystallization, and Crystal Morphology

Determining Degree of Saturation after Application of Transiently Supersaturated Metered Dose Aerosols for Topical Delivery of Corticosteroids

Precipitation of nesquehonite from homogeneous supersaturated solutions

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