Controllable Synthesis, Characterization and Flame Retardant Properties of Three Kinds of α-4CaO5B2O37H2O Nanostructures Constructed by Nanoflakes

Calcium borate α-4CaO•5B2O3•7H2O nanoflake and spherical-, silkworm chrysalis-like 4CaO•5B2O3•7H2O nanostructure constructed by nanoflake have been synthesized under hydrothermal conditions at 120 °C with Ca(NO3)2•4H2O and Na2B4O7•10H2O as materials, using water and ethanol as mixture solvent. The as-prepared products were characterized by the XRD, EDS, FT-IR and SEM. The influences of reaction temperature, reaction time, solvent and surfactant on the morphology and size of calcium borate α-4CaO•5B2O3•7H2O have also been investigated. The possible formation mechanisms of α-4CaO•5B2O3•7H2O nanostructures have been proposed. Furthermore, the flame retardant properties of the prepared α-4CaO•5B2O3•7H2O nanostructures were investigated by the thermal analysis method, demonstrating that they had the better behaviors than the non-nanostructure sample.