Controlling the Morphology of BaCO₃Aggregates by Carboxymethyl Cellulose through Polymer Induced Needle-Stacking Self-Assembly

Abstract

Inspired by mineralization in biological organisms, fabrication of higher ordered inorganic crystals induced by polymer chains has received much attention. In our present work, we made use of a widely used industrial material, carboxymethyl cellulose (CMC), to mediate the nucleation and growth of barium carbonate (BaCO3). We calculated the interactions between CMC chains and crystalline needle-like units of BaCO3 by molecular dynamic simulation, concluding that the (111) face of crystalline units is the most favorable face for CMC chains to attach onto. Based on the simulation results and the time-resolved experiments, we suggested the dumbbell-like BaCO3 aggregates formed via polymer induced stacking of needle-like units. More importantly, we realized control over the morphology of aggregates from dumbbell-like to spherical particles by simply adjusting the polymer concentration. By clarifying the aggregation mechanism mediated by polymer chains, we demonstrate here not only a simple method to fabricate BaCO3 particles with controllable morphologies but also a reference work which may serve the exploration of the mechanism in biomineralization.

Controlling the polymorph and morphology of CaCO3 crystals using surfactant mixtures

“…6C. Similar results were reported in which carboxymethyl cellulose was used to modify the growth processes of BaCO 3 [5]. The flower-like vaterite transformed to aragonite via dissolution-recrystallization processes with increase of the reaction time as shown in Scheme 1D.…”

“…This kind of growth may take place through aggregation of some needle-like structures. Based on a similar result reported in [5], in which a polymer was used instead of the surfactants, we propose the formation processes of the aragonite in the present experiment as the following. The surfactants were extruded from aggregates and then attached onto the end of needle-like units but not the middle part.…”

“…Production of higher ordered inorganic crystals by a self-assembly process has received much attention not only for its importance on crystallization theories but also for the potential to design new materials used in many fields, such as electronics, catalysis, and ceramics [1][2][3][4][5]. Self-assembly is used in biological systems to regulate the synthesis of biominerals with hierarchical structures and specialized functions including protection and structural support, such as bones and shells [6,7].…”

Fabrication of BaCO3 sheaves tailored by carboxymethyl cellulose under compressed CO2

“…1). Since needle-like structure reflected the interior properties of the BaCO 3 cell [38], the existence of needles among rods was probably induced by the replication and amplification of the witherite cell through ion-byion attachment.…”

“…Our group have previously utilized CMC chains to modulate the crystallization of BaCO 3 under gas-diffusion way (slow carbonation rate) and found out CMC chain selectively absorbed onto witherite faces which induced the aggregating process of witherite units [38]. On the other hand, when the carbonation route with supercritical CO 2 was adopted, due to the fast carbonation rate, CMC chains acted as ''direct skeletons'' and the ions in the reaction system attached onto the polymer skeletons to grow in situ [27].…”