Calcium carbonate CaCO incorporation

P-Tiicalcium phosphate (P-TCP) fillers were also used in PCL electrospun fibers [65,67] to obtain bioactive nanocomposite fibers for applications in the bone tissue engineering field, as weU as calcium carbonate (CaCOs), which was incorporated in PCL membranes for guided bone regeneration [68]. 

The thermal stability of calcium carbonate (CaC03) nanoparticles on polybutadiene rubber (PBR) were studied by Shimpi and Mishra [105]. They observed that the incorporation of nano CaCOs in PBR shows better thermal stability. At 12 wt% of nano CaCOs (21, 15, and 9 nm) filled in PBR shows decomposition temperature at 491, 483, and 472 °C, respectively. At 4 wt% loading of filler, decomposition temperature is observed to be 488,480,450 °C for nano CaCOs (21, 15, and 9 nm), respectively. This enhancement in thermal stability is due to uniform dispersion of nano CaCOs throughout the matrix that keeps the rubber chains intact on cross-linking, which prevent out diffusion of the volatile decomposition product [106]. The presence of nanoinorganic particles in between the mbber chains is responsible for preventing the diffusion of the volatile decomposition products firom the mbber nanocomposites at same time. It is clear that nanoinorganic filler provides better thermal stability as compared with commercial micron size filler. 

In other cases, homemade matrix-matched standards have been prepared. For instance, Ulens et al. used CaCOs pellets doped with known amounts of the analytes for marble analysis [9]. Pereira et al. prepared synthetic obsidian standards based on the coprecipitation of trace elements in alumina and calcium carbonate, followed by the incorporation of the precipitates into a glass frit, for analysis of natural obsidian... 

An important consequence is that radiocarbon is incorporated within the CaCOs crystals and begins to decay from the time of precipatation. As no carbon exchange can happen in the solid phase of calcium carbonate, contained in lime based mortars, plasters and renders can be used to date these materials with the radiocarbon method. 

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