Iron oxide nanoparticles were incorporated to form composite microspheres of SiO2 and Fe2O3 for magnetic separation of the particles after adsorption or photochemical decomposition. Economic material, sodium silicate, was purified by ion exchange to prepare aqueous silicic acid solution, followed by mixing with iron oxide nanoparticles. Resulting aqueous dispersion was emulsified, and composite microspheres of SiO2 and Fe2O3 was formed from the emulsion droplets as micro-reactors during heating. Removal of methylene blue using the composite microspheres was performed by batch adsorption process. Synthesis of composite microspheres of silica containing Fe2O3 and TiO2 nanoparticles was also possible, the particles could be separated using magnets efficiently after removal of organic dye.

The study of liquid crystalline assemblies, with an emphasis on biological phenomena, is now accessible using newly developed microdevices integrated with X-ray analysis capability. Many biological systems can be described in terms of gradients, mixing, and confinement, all of which can be mimicked with the use of appropriate microfluidic designs. The use of hydrodynamic focusing creates well-defined mixing conditions that vary depending on parameters such as device geometry, and can be quantified with finite element modelling.We describe experiments in which geometry and strain rate induce finite changes in liquid crystalline orientation. We also demonstrate the online supramolecular assembly of lipoplexes. The measurement of lipoplex orientation as a function of flow velocity allows us to record a relaxation process of the lipoplexes, as evidenced by a remarkable 4-fold azimuthal symmetry. All of these processes are accessible due to the intentional integration of design elements in the microdevices.