Measurement of Crystal Face Specific Growth Kinetics

Abstract

An instrument for measurement of face specific growth kinetics of crystals growing in a solution is developed and applied to crystallization of sodium nitrate (NaNO3) and potassium dihydrogen phosphate (KH2PO4, KDP). The device consists of three major components, a stereovision imaging system that captures in real-time the size change in each face direction of the crystal, an ATR-FTIR probe measuring solution concentration and supersaturation, and a small purpose-designed crystallizer that allows a crystal to be fixed in the solution and adequate solution mixing so the concentration measured can reflect the solution concentration near the surfaces of the crystal. The growth rates of all independent faces of NaNO3 and KDP crystals were derived at each time interval. For the NaNO3 crystal, growth rates in the temperature range of 298.15 ~ 318.15 K and supersaturation range of 0.01 ~ 0.11 were measured, enabling a systematic kinetic study. For the KDP crystal, the growth rates were measured just to show the capability of the system in handling crystals with different morphologies.

A multi-stage multi-component transfer rate morphological population balance model for crystallization processes

“…The liquid mass transfer coefficients can be calculated based on correlation equation given by Geankoplis 12 and the necessary property parameters of diffusivity, density and viscosity aqueous NaNO3 and KNO3 can be found in the work of Graber et al 13 . Other parameters corresponding to NaNO3 can be regressed according to the solubility data 14 15 , and the facet growth rate measurement given by Wu et al 10 . Their values are in Table 1.…”

Toward Understanding the Growth of Cefradine in Aqueous Solution

“…For methodology development, many studies have reported that seeded isothermal desupersaturation or single crystal growth methods are effective to study crystal growth kinetics of organic compounds under different crystallization environments. Some researchers also designed new methods to accomplish the observation of specific face growth of massive crystals simultaneously and 3D vision observation of the crystal growth rate of all the surfaces, such as using the rotating disk and the stereovision imaging system . Besides, for the growth mechanism, many researchers have shown that the growth units are transported from bulk solution to crystal face through mass transfer during the crystal growth process, and then integrated into incorporation sites at the surface followed by desolvation .…”

In Situ Measurement of 3D Crystal Size Distribution by Double-View Image Analysis with Case Study onl-Glutamic Acid Crystallization

“…Recently, a new dual-camera measurement device was developed for real-time monitoring of particle shapes rather than 3D size measurement via a circulating pipeline, based on an image segmentation algorithm for background extraction and a volume intersection method for classification of different 3D particle shapes. Ma et al presented a proof-of-concept of 3D shape reconstruction based on using two no-invasive cameras installed with a prespecified angle to synchronously capture images, which was further extended in the references , for roughly estimating 3D size growth of crystals rather than quantitative measurement. For using a binocular microvision system to capture stereo images for analysis, a few calibration methods for guaranteeing the measurement accuracy were reported in the references, , but these methods could not be used for in situ installed microvision systems subject to uneven illumination background, particle motion, and solution turbulence usually involved with crystallization processes.…”