Effect of Alginate from Chilean Lessonia nigrescens and MWCNTs on CaCO3 Crystallization by Classical and Non-Classical Methods

Abstract

Abstract:In our crystallization experiments, the influence of alginate from Chilean Lessonia nigrescens and functionalized multi-walled carbon nanotubes (MWCNTs) was tested through electrocrystallization (EC) and gas diffusion (GD) methods on the crystal growth of calcium carbonate (CaCO 3 ) and their possible stabilization of proto-structures in amorphous CaCO 3 (ACC) state through pre-nucleation clusters (PNC) essays with automatic potentiometric titrations were performed. CaCO 3 crystals obtained in the in vitro above-mentioned crystallization systems were characterized by scanning electron microscope (SEM), energy-dispersive X-ray spectrometry (EDS) and powder X-ray diffractometer (XRD). Our experimental findings showed that ALG and functionalized MWCNTs stabilized truncated and agglomerated vaterite-like particles through GD and EC methods. While, on the other hand, we obtained qualitative information about induction or inhibition of CaCO 3 nucleation that was provided by potentiometric titrations.

Effect of Functionalized Multiwalled CNTs on the Selective Formation of Calcium Oxalate Crystals by Electrocrystallization

“…It was also found that the potentiometric response curves begin to stabilize by increasing the temperature, and the effect of the system decreases the variation between each point measured in the EC of CaOx. In addition, we reported that anionic MWCNTs also acted as efficient inhibitors in the in vitro CaCO 3 crystallization …”

“…In addition, we reported that anionic MWCNTs also acted as efficient inhibitors in the in vitro CaCO 3 crystallization. 31 Herein, MWCNT-IA was a better inhibitor template than the well-known organic citrate, which was used to inhibit the EC of CaOx at 37 and 60 °C. The morphology (Figure 4) and hydrated crystal forms (Figure 5) of CaOx obtained via EC using citrate and all the MWCNTs by applying a 9 mA current for 5 min in a closed system at 37 or 60 °C were analyzed by SEM and XRD, respectively.…”

Application of Response Surface Methodology for Optimization of the Biosorption Process from Copper-Containing Wastewater

“…Abundant functional groups have been found in sodium alginate, such as carboxyl and hydroxyl groups, which can crosslink with cations [ 11 , 12 ]. Sodium alginate reacts with divalent cations such as Ca(II), Ba(II) and Sr(II) to form insoluble hydrogels, which are crosslinked to form a reticular structure called the “egg box”, and the crosslinking pathway is the exchange between the sodium ions of α-L-guluronic acid and divalent ions [ 13 , 14 ]. In addition, alginate beads can be easily recovered [ 15 , 16 ].…”

Carbonates

“…Sánchez and coworkers [2] started from the same assumption regarding the role exerted by biological functional molecules during the crystallization of carbonates. They introduced the effect of inorganic precursor species (IPS), namely amorphous phases and pre-nucleation clusters (PNCs) in order to understand the interactions between organic and inorganic phases, and discussed the effect of plain carbon nanotubes (CNTs) and alginate-functionalized CNTs on the nucleation and growth of carbonates using electrochemical (EC) and gas diffusion (GD) techniques.…”