Fine-grained amorphous calcium silicate CaSiO3 from vacuum dried sol–gel – Production, characterisation and thermal behaviour

Non-aqueous formation of the calcium carbonate polymorph vaterite: astrophysical implications

“…In this case, the additional pressure required to observe a reaction when using the quartz capillary is not believed to be due to any difference in the sample but merely represents the additional pressure required to allow the gas to diffuse through the full length of the capillary. Thompson et al (2012a) reported the carbonation of the same amorphous samples in a vacuum desiccator using ammonium carbonate as the source of CO 2 , supporting the fact that the need for higher pressure in this study is solely due to the experimental setup, and is not necessary for such a reaction to occur.…”

“…An amorphous calcium-rich silicate was produced via a sol gel method (described in detail by Thompson et al 2012a), in which the metal salts CaCl 2 and Na 2 SiO 3 were combined in 0.1M solutions to form samples having the stoichiometric composition CaSiO 3 . In order to prevent carbonation of the final samples through the interaction with atmospheric CO 2 , they were stored in gel form under demineralised water until required, at which point the gels were dried in a carbolite HVT vacuum furnace (P < 10 −4 mbar), initially purged with nitrogen.…”

Mechanical and microstructure of reinforced hydroxyapatite/calcium silicate nano-composites materials

“…Sol-gel processing allows production of gel glasses with compositions lying within the liquid-liquid immiscibility of the CaSiO 3 system [15]. The use of sol-gel procedures for synthesizing non-crystalline Ca-silicate has driven in part by the potential scalability for industrial manufacture and by the often more desirable properties of the final product over other methods for certain applications [16]. The physical properties of the resulting amorphous CaSiO 3 product are characterized and reported as its crystallization to wollastonite under thermal processing prepared in the stoichiometric quantities necessary to give a CaSiO 3 product via:…”

Synthesis and characterization of spherical amorphous alumo-silicate nanoparticles using RF thermal plasma method

“…The sharp peaks that can be seen in the FTIR spectra at around 1400 cm −1 could be attributed to ionic carbonate [25,26]. However, no traces of metal carbonates were determined in the samples by XRD analysis, probably, due to morphous character of carbonates or concentrations are lower detection limit by XRD [27]. Broad bands between 3600 and 3000 cm −1 and absorptions located at ~1640 cm −1 are due to water adsorbed from atmosphere.…”