•Tetraethoxysilane phase is compressed and restricted as a liquid core after monomers polymerize.•Hybrid microcapsules were obtained via in situ miniemulsion polymerization.•Magnetic microcapsules are obtained conveniently by adding hydrophobic Fe3O4 nanoparticles in the oil phase.Magnetic hybrid-shell microcapsules were fabricated by restricting tetraethoxysilane (TEOS) phase as a liquid core due to the phase separation via one-step miniemulsion polymerization. The inner void size of magnetic hybrid-shell microcapsules could be easily tuned by adjusting the TEOS content in the miniemulsion formulation. The magnetic hybrid-shell microcapsules were characterized by FTIR, transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The results showed that magnetic hybrid-shell microcapsules had an average size of 200–600 nm and the saturation magnetization values of the samples were 14.7 and 18.3 emu/g. The magnetic microcapsule may provide a very promising vehicle for drug delivery, catalysis, and photoelectric materials.

This paper reports a rapid and facile method of preparing free-standing colloidal crystals from monodisperse charged polystyrene (PS) microspheres. Mixed solvents (ethanol/water) were used as the dispersion medium in the self-assembly process of colloidal crystals. By a simple “floating self-assembly” method, PS microspheres floated on the surface of liquid and self-assembled into large area of three-dimensional (3D) ordered colloidal crystals within 15 min. Then epichlorohydrin was added in as a cross-linking agent to strengthen the colloidal-crystal film. After cross-linking reactions between the microspheres, the obtained colloidal-crystal film was free-standing and could be easily transferred to other substrates. Using tetrabutyl titanate as a titania precursor, 3D porous TiO2 materials with rodlike skeletal structure were fabricated from the prepared free-standing colloidal crystal. This work provides a facile method to fabricate free-standing colloidal-crystal film, which can be used as an ideal template for the preparation of porous materials.Graphical abstractOptical photographs of colloidal multi-layers from PS microspheres of different size: (a) 140 nm, (b) 216 nm, and (c) 282 nm. (d and e) show the free-standing colloidal films prepared from 158 nm microspheres.Research highlights► Colloidal crystals are fabricated via “floating self-assembly” method within 15 min. ► Free-standing colloidal-crystal film is obtained using epichlorohydrin as cross-linking agent. ► Free-standing colloidal crystals could be used as ideal templates for 3DOM materials.