YU Hongmei, XU Yi, LIU Ke, et al. Effect of magnetic nanoparticles on isothermal crystallization behaviors of devitrified Vs55[J]. CIESC Journal, 2017, (3).
DOI:
YU Hongmei, XU Yi, LIU Ke, et al. Effect of magnetic nanoparticles on isothermal crystallization behaviors of devitrified Vs55[J]. CIESC Journal, 2017, (3).DOI: 10.11949/j.issn.0438-1157.20161440.
Effect of magnetic nanoparticles on isothermal crystallization behaviors of devitrified Vs55
The effect of magnetic nanoparticles(MNPs) on the devitrification isothermal crystallization of typical vitrification solution Vs55 in the process of glass crystallization was systematically explored by Differential Scanning Calorimetry (DSC) and cryomicroscope system. The results show that:(1)The MNPs coated by both Carboxylic Acid (CA) and Polyethylene Glycol (PEG) have little effect on the glass transition temperature(Tg) of Vs55
but significant effect on the devitrification transition temperature(Td) and devitrification enthalpy(HTd);(2)At the range of the devitrification area (-85~-60℃)
the MNPs coated by CA can significantly promote the devitrification of Vs55 as increasing of the isothermal temperatures and the cooling rates
and the ice growth rate was 0.37 μm·s-1 at the isothermal temperature of -85℃
but it is about 2.19 μm·s-1 for -75℃. Also
the ice growth rates raised from 1.72 μm·s-1 to 3.54 μm·s-1 when the cooling rates were increased from 2℃·min-1 to 100℃·min-1(at the isothermal temperature of -75℃); (3) Compared with Vs55
magnetic nanoparticles coated by both PEG and CA could promote the devitrification of Vs55. The crystal growth rates at the isothermal temperature of -80℃ were 0 for Vs55
but 1.04 μm·s-1 and 2.31 μm·s-1 for CA and PEG respectively. Compared with CA coating
the MNPs coated by PEG promoted the much more devitrification of Vs55
and the ice growth rates were 0.62 μm·s-1 and 6.25 μm·s-1 for the isothermal temperature of -85℃ and -75℃
respectively
which means that the surface coating of MNPs can significantly affect the crystallization of Vs55.