A bio-inspired route to fabricate submicrometer-sized particles with unusual shapes -: Mineralization of calcium carbonate within hydrogel spheres

Submicrometer-sized inorganic-organic composite particles with disklike, cell-like, and hemispheroidal shapes have been fabricated by in-situ mineralization of CaCO3 within hydrogel spheres of poly(N-isopropylacrylamide-co-(4-vinylpyridine)) (PNIPVP). The shape and functionality of the composite particles obtained may be manipulated by incorporating nanocrystals into hydrogel sphere templates. Our methodology paves a novel way to create sub- or micrometer-sized particles with complex shapes, inspired by biomineralization embodied in single-cellulous organisms. Also, the composite particles obtained present a transition phase between soft and hard spheres, which may self-organize into non-close-hexagonal packing structures.