Synthesis of Micro-/Nanohydroxyapatite Assisted by the Taylor–Couette Flow Reactor

Abstract

Hydroxyapatite (HAP) has received increasing attention as an essential chemical product with good biocompatibility and adsorption properties. Generally, amorphous calcium phosphate (ACP) was generated first in the reactor and transformed into HAP after a period of crystallization. In this work, a series of Taylor–Couette flow reactors with different inner diameters were designed to assist in synthesizing HAP micro-/nanocrystals. ACP was obtained in a Taylor–Couette flow reactor at Re = 247 and successfully transformed into needle-like HAP crystals with a length of about 200 nm and a uniform particle size distribution after crystallization transformation. The yield of a single reactor can reach 2.16 kg per day. The finite element analysis results and time–space diagram of flow pattern variation showed that the Taylor–Couette flow reactor could improve the mixing behavior and the flow field distribution. The Taylor–Couette flow reactor provides a valuable reference for synthesizing inorganic micro-/nanomaterials.

Enhancement and Regulation of Peptide Crystallization with the Application of Taylor Vortex: A Case Study of Vancomycin

“…For a better comparison of the performance between the CT and MT crystallization processes, the Reynolds number (Re) for the MT and CT crystallizers was controlled to be the same. It is well-known that Re is the most commonly used dimensionless number to describe the state of a fluid, which determines whether a fluid is in a laminar or turbulent state in many fluid dynamics problems . Re CT of the CT crystallizer is defined by eq Re CT = R I ω 1 d ρ μ where R I is the radius of the glass rod, ω 1 is the rotation velocity of the glass rod, d is the gap between the inner and outer cylinders, ρ is the fluid density, and μ is the dynamic viscosity of the liquid.…”

“…It is well-known that Re is the most commonly used dimensionless number to describe the state of a fluid, which determines whether a fluid is in a laminar or turbulent state in many fluid dynamics problems. 18 Re CT of the CT crystallizer is defined by eq 5 29…”

“…The Taylor vortex in the crystallizer can improve the mixing behavior and the flow field distribution, which can effectively enhance heat and mass transfer. 18 Moreover, the Taylor vortex can produce a uniform shear force, which can effectively strengthen the crystallization process and obtain crystalline products with a uniform particle size distribution. 19 It is reported that the Taylor vortex has been applied to a variety of processes in industrial crystallization such as reaction crystallization, drowning-out crystallization, and cooling crystallization.…”

“…In the Taylor vortex device, the mixing strength is controlled mainly by adjusting the speed and gap width. The Taylor vortex in the crystallizer can improve the mixing behavior and the flow field distribution, which can effectively enhance heat and mass transfer . Moreover, the Taylor vortex can produce a uniform shear force, which can effectively strengthen the crystallization process and obtain crystalline products with a uniform particle size distribution .…”

“…19 Kim et al 20 demonstrated from both experimental and modeling prospects that Taylor vortex has a better mass transfer effect than random turbulence, thus promoting stable polycrystalline nucleation and phase transition of histidine. Wang et al 18 used the Taylor vortex to improve the mixing behavior, so that the velocity distribution of the flow field was uniform, and hydroxyapatite with uniform particle size distribution was obtained efficiently, which provided a reference for the synthesis of inorganic micronanomaterials. The Taylor vortex has also been reported to have great advantages in enhancing the crystallization of biomacromolecule drugs.…”