Synthesis of Nano Calcium Hydroxide in Aqueous Medium

Abstract

The present work reports a simple, inexpensive method for synthesis of calcium hydroxide [Ca(OH) 2 ] nanoparticles (CHNPs). The method involves chemical precipitation (CP) in aqueous medium at room temperature. Calcium nitrate dihydrate [Ca (NO 3 ) 2 .2H 2 O] and sodium hydroxide were used as precursors. The CHNPs were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Rietveld analysis, field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM), BET surface area evaluation as well as particle size distribution analysis techniques. The results confirmed the synthesis of CHNPs as the major phase. The CHNPs exhibited an average size of about 350 nm. In addition, some calcite phase formed due to the inevitable carbonation process. A very minor amount of aragonite phase was also present. A schematically developed new qualitative model is proposed to explain the genesis and subsequent evolution of the various phases at the nanoscale. The model helps to identify the rate-controlling step. It also highlights the implication of reaction kinetics control in synthesis of predesigned nanophase assembly.

Synthesis, characterization, and catalytic application of ecofriendly Ca‐bridged aminoclay

“…The Ca‐AC system showed better results as compared with the literature. The biosource‐mediated catalytic reduction of chromium (VI) yielded the k app value of 1.39 × 10 −3 s −1 . Our report is closely related to the literature report.…”

Graphene‐Enhanced Nanomaterials for Wall Painting Protection

“…The carbonation of Ca(OH) 2 /GQD nanohybrids and two control Ca(OH) 2 materials dispersed in IPA were carried out by depositing on glass slides and storing in a humidity chamber at 23 ± 2 °C and 50 ± 5% relative humidity. The degree of carbonation of these materials was monitored every 3 d followed by the Rietveld method using an XRD line profile . For the two control Ca(OH) 2 materials, the Ca(OH) 2 peaks become weak, and calcium carbonate peaks appear over time (Figure e,f).…”

Nano Ca(OH)2synthesis using a cost‐effective and innovative method: Reactivity study

“…The reduction in particle dimensions to a sub-micrometric scale can also lead to higher reactivity, such as the faster carbonation process of mortars prepared by aged lime putty compared with mortars containing commercially available, hydrated lime. [19][20][21][22][23] Moreover, Ca(OH) 2 is rarely the only product of the reaction, requiring time-consuming purification. 18 Currently, typical procedures adopted to prepare submicrometric (or nano-sized) and plate-like Ca(OH) 2 particles consist of wet chemical methods, carried out at high temperature and/or at high pressure, in aqueous, alcohol or organic solvents.…”

“…18 Currently, typical procedures adopted to prepare submicrometric (or nano-sized) and plate-like Ca(OH) 2 particles consist of wet chemical methods, carried out at high temperature and/or at high pressure, in aqueous, alcohol or organic solvents. [19][20][21][22][23] Moreover, Ca(OH) 2 is rarely the only product of the reaction, requiring time-consuming purification. Purification is also needed to eliminate the organic compounds, used in the synthesis medium, requiring accurate procedures because of the adsorption on the nanoparticle surfaces, and leading to higher costs and low-yield synthesis.…”