High-efficient crystal particle manufacture by microscale process intensification technology

High-end crystal manufacture has drawn a permanent concern on the high-efficient manufacture of crystal particles, especially in fine chemical, pharmaceutical, electronics, biological and relative engineering fields. In recent years, a series of microscale process intensification (MPI) technologies have been widely used in crystal particles preparation via addressing the control of nucleation and growth process. Herein, we review the research progresses of microscale process intensification technology from three aspects, microfluidics devices, microscale force field technology and membrane-based microchannels and interface transfer process. Firstly, the principle of microfluidic and relative microscale device on improving micro-mixing and mass transfer are briefly described. The advantage of microfluidic in continuous nano particle preparation is outlined. Microscale external force field (ultrasonic, high-gravity, electric and magnetic fields) is then introduced as another novel approach for ultrafine nanoparticles and continuous drug crystallization process. Further, in view of the micro-scale intensified mass transfer and microscale interfacial force field established on membrane technology, the basic mechanism of membrane crystallization (microscale 2D supersaturation degree control, auto seed detachment, microporous membrane dispersion, etc.) is reviewed. The process coupling and design strategy aiming for enhancing the manufacture capacity is also illustrated. Finally, the developing tendency and key challenges of high-efficient crystal particle preparation technology via microscale processes are overviewed.