Figure 3.

Morphology changes of the thermal treated vaterite microspheres when incubated in a flowing water: (a, e, i, m) M-0; (b, f, j, n) M-300; (c, g, k, o) M-305; and (d, h, l, p) M-310. The incubation times for the samples were as follows: (a, b, c, d) 2 days; (e, f, g, h) 4 days; (I, j, k, l) 6 days; and (m, n, o, p) 8days. More rapid vaterite-calcite transitions occurred following the decrease of silk content inside the microspheres.