CaCO₃Biomineralization in Microfluidic Crystallizer

Abstract

− Crystallization of CaCO 3 is practiced on a polymethylsiloxane (PDMS) -based microfluidic system. Liquid-liquid reaction was investigated by mixing calcium chloride (CaCl 2 ) and sodium carbonate (Na 2 CO 3 ) solution to crystallize CaCO 3 . Aspartic acid (Asp) was added to investigate the morphology change such as vaterite and calcite. Suitable ratio of Na 2 CO 3 and CaCl 2 was searched for initial seed formation. Christmas tree model was used as microfluidic device to form concentration gradient of Na 2 CO 3 and CaCl 2 . After observing microfluidic channel by using optical microscope, we found that seeds of CaCO 3 were formed under the condition that the ratio of Na 2 CO 3 and CaCl 2 was 2:1. Morphology of crystals were also observed as CaCO 3 crystals grow. When Asp was added, vaterite crystal was more frequently found in two morphologies (vaterite and calcite) and seed formation and crystal growth were inhibited.

Aragonite crystallization in a Christmas-tree model microfluidic device with the addition of magnesium ions

“…5D and 5E). These results are not in agreement with previous reports in which solutions were adjusted to pH 7.5 and the feed concentrations were threefold greater than those used in this study [36]. Thus, the feed concentration and pH of the solutions influence the main mechanism (growth or formation).…”

“…2 [36]. After SU-8 (NIPPON KAYAKU, Japan) was poured onto a Si-wafer (K1 solution, Korea), spin coating was conducted at 2,300 rpm for 30 sec using a Spin 1200D (MIDAS, England) to obtain a 60 µm SU-8 layer.…”

“…This device is useful for determining the effect of concentration gradients. Kim et al investigated the effect of aspartic acid on CaCO 3 crystallization morphology in this device [36].…”

Microfluidic Control of Nucleation and Growth of CaCO3

“…Studies in nucleation and growth of CaCO 3 polymorphs in microfluidics are mainly intended to cast light on fundamental aspects of inorganic CaCO 3 crystallization pathways [37][38][39] or biomimetic or biomineralization processes. [40][41][42][43][44][45][46][47][48][49] Zeng et al 39 used microfluidics to control the formation of ACC and transformation pathways to vaterite and calcite, Li et al 38 also studied crystallization pathways but included the use of FTIR in microfluidics and Rodriguez-Ruiz 37 studied how confinement in microfluidic reactors stabilized the hydrated CaCO 3 mineral ikaite. Yashina et al 45 In another set of studies 40,43,44 they mixed Na 2 CO 3 and CaCl 2 with and without mollusk shell proteins in a microfluidic T-junction to study CaCO 3 crystallization polymorphs.…”

“…Studies in nucleation and growth of CaCO 3 polymorphs in microfluidics are mainly intended to cast light on fundamental aspects of inorganic CaCO 3 crystallization pathways − or biomimetic or biomineralization processes. − …”