ABSTRACT We report a method for the coacervation micro-encapsulation of several forms of CaCO3 microparticles with the fluoropolymer poly(heptadecafluorodecyl acrylate) (poly (HDFDA)) by pressure-induced phase separation of a supercritical CO2 solution. A suspension of CaCO3 in CO2 and dissolved poly(HDFDA) were mixed in supercritical CO2. After the system pressure was slowly decreased to atmospheric pressure, the microcapsules were obtained. Coacervation was achieved by the precipitation of poly(HDFDA) during the decrease in the pressure of CO2; the solubility of poly(HDFDA) in CO2 decreased with the pressure. The structure and morphology of the microparticles were investigated by using a scanning electron microscope (SEM) and an electron probe microanalyzer (EPMA) equipped with a wavelength dispersive X-ray spectroscope (WDX).
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K. Mishima, H. Yokota, T. Kato, T. Suetsugu, X. Wei, K. Irie, K. Mishima and M. Fujiwara, "Coacervation Microencapsulation of CaCO3 Particles with a Fluoropolymer by Pressure-induced Phase Separation of Supercritical Carbon Dioxide Solutions," Advances in Materials Physics and Chemistry, Vol. 2 No. 4, 2012, pp. 181-184. doi: 10.4236/ampc.2012.24B047.
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