TITLE:
A New and Original Method to Produce Ca(OH)2 Nanoparticles by Using an Anion Exchange Resin
AUTHORS:
Giuliana Taglieri, Valeria Daniele, Giovanni Del Re, Roberto Volpe
KEYWORDS:
Ca(OH)2, Nanolime, Nanoparticles Synthesis, Characterization, Anion Exchange Resin, Carbonatation Process
JOURNAL NAME:
Advances in Nanoparticles,
Vol.4 No.2,
April
2,
2015
ABSTRACT: Ca(OH)2 nanoparticles in hydro-alcoholic dispersion (nanolime) were successfully employed in
Cultural Heritage conservation, thanks to the ability to overcome the limiting aspects of traditional
lime treatments. Nanolime were currently produced by chemical precipitation process, at
high temperature, with long times of synthesis, and after several purification steps to remove undesired
secondary phases. In this paper, an innovative, simple and original method for nanolime
production was described. The method was based on an ion exchange process between an anionic
resin and a calcium chloride aqueous solution, operating at room temperature. A pure Ca(OH)2 nanoparticles suspension can be rapidly obtained after separating the resin from suspension, and
any purification step was necessary. The exhausted resins can be regenerated and reused for a cyclic
nanolime production. Structural and morphological features of the produced nanolime were
preliminarily characterized by X-ray diffraction (XRD) and transmission electron microscopy
(TEM). Moreover, XRD measurements allowed estimating nanoparticles reactivity by following
their carbonatation process in air, in relation to different water/alcohol ratios and medium or
high relative humidity conditions. The produced Ca(OH)2 nanoparticles appeared hexagonally
plated, with dimension less than 100 nm and, compared with those obtained by typical wet precipitation
method, they proved to be more reactive.