칼슘 나노분말과 마이크로 분말의 이화학적 특성 비교

The aim of this study was to compare the physicochemical properties of calcium carbonate nano- and micro-powders for safe food applications of nanomaterials. The morphologies and approximate sizes of calcium particles were observed by scanning electron and transmission electron microscopic methods, showing hexagonal shape with sharp and rough surface. The approximate sizes of the calcium nano- and micro-particles observed on the micrographs were around 100 nm and 100 nm to 3 μm, respectively. The average particle sizes of the calcium nano- and micropowders determined by the dynamic light scattering method were 440.2±73.8 and 547.1±105.3 nm at 0.5 mg/mL particle concentration and 388.8±123.2 and 1001.9±160.4 nm at 1.0 mg/mL particle concentration, respectively. The zeta-potential of the calcium nano- and micro-powders were -9.94±1.78 and -2.42±2.38 mV, respectively. It seemed that both calcium nano- and micro-powders were unstable in aqueous conditions but calcium nano-powder was relatively more stable. The results of specific surface area of the calcium nano- and micro-powders were 6.99 and 4.26 m²/g while the bulk densities of them were similar but the tap densities were 0.81±0.02 and 0.97±0.02 g/mL, respectively. The angles of repose were 35.40±1.32° (nano-powder) and 39.37±2.46° (micro-powder), implying that calcium nano-powder was more flowable. This study provides a potential of various mineral nanoparticles including calcium nanoparticles for future safe food applications.