A Low-Cost System Based on Image Analysis for Monitoring the Crystal Growth Process.

Fabrício Venâncio,João Cajaiba,Francisca Rosário

doi:10.3390/s17061248

Fabrício Venâncio, João Cajaiba + Show 1 more

Open Access

https://doi.org/10.3390/s17061248

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Abstract

Many techniques are used to monitor one or more of the phenomena involved in the crystallization process. One of the challenges in crystal growth monitoring is finding techniques that allow direct interpretation of the data. The present study used a low-cost system, composed of a commercial webcam and a simple white LED (Light Emitting Diode) illuminator, to follow the calcium carbonate crystal growth process. The experiments were followed with focused beam reflectance measurement (FBRM), a common technique for obtaining information about the formation and growth of crystals. The images obtained in real time were treated with the red, blue, and green (RGB) system. The results showed a qualitative response of the system to crystal formation and growth processes, as there was an observed decrease in the signal as the growth process occurred. Control of the crystal growth was managed by increasing the viscosity of the test solution with the addition of monoethylene glycol (MEG) at 30% and 70% in a mass to mass relationship, providing different profiles of the RGB average curves. The decrease in the average RGB value became slower as the concentration of MEG was increased; this reflected a lag in the growth process that was proven by the FBRM.

Highlights

The observation of the onset of crystallization and monitoring of the crystal growth process are fundamental to understand crystal growth kinetics
The results show that it is possible to draw qualitative conclusions about crystal formation and the the crystal growth process using our system
Crystal growth was manipulated by increasing the viscosity of the test media, resulting imaging system

Summary

Introduction

The observation of the onset of crystallization and monitoring of the crystal growth process are fundamental to understand crystal growth kinetics. Low-cost systems that have been proposed for watching crystallization phenomena are focused on detecting the onset of crystallization [12] or building solubility curves [13] These online imaging techniques carry the advantage of having a large analysis area in the camera, mapping a suitable amount of the reaction media. Sena et al [15] used the RGB system to treat the images provided by calciuma carbonate precipitation, while the viscosity of the solution manipulated so that we webcam to detect low concentrations of barium sulfate in a test suspension andwas present the relationship could observe changes in the crystal growth phenomenon. Silva et al [13] used the same imaging system to build solubility curves with a quantitative approach These studies were focused on signals, an FBRM probe was inserted in the reaction media to monitor the reaction. Used a low-cost online imaging system to follow the crystal growth process during

MaterialsThis andstudy

Influence of Different

Calcium

Results and Discussion

Conclusions