Preparation And Properties Of Templated Layered Double Hydroxide Microsphere With Controllable Morphology

Well-controlled nanostructures obtained via template-directed synthesis have generated diverse scientific and technological interests, since the tunable morphology is of utmost importance for optimization in many potential areas of applications such as energy conversion, electronics, catalysis, optics, chemical sensing, and medicine. The ability to control morphologies of hierarchical spheres often combines fascinating shapes with remarkable properties, which requires a high level of control of structure, size, morphology, and orientation by assembly at template surfaces. Layered double hydroxides (LDHs), also known as hydrotalcite-like layered clays, have widely been investigated as a class of anionic lamellar multifunctional materials. Important advances in LDH morphology have been made in the past, mainly focusing on microsized LDHs such as spheres, curved belts, and hydrothermally synthesized LDH films with microsized LDH platelets oriented perpendicularly or horizontally to the underlying metal or surface-modified substrates. Spherical structures are of particular interest for a number of different applications, such as catalysts, sorbents, lithium-ion battery electrodes, and carriers for cellular drug and gene delivery. Reports of the deliberate control of colloidal LDH micro/nanostructures are, however, still quite scarce.In this present study, we report on preparation of LDH shell spheres with controllable morphologies using a protocol combining typical coprecipitation and hard template. Preliminary investigations on the drug's absorption and releasing properties of the obtained shell spheres were also performed. MgAl-LDHs. The obtained results are presented as follows.1. Flower-like MgAl-LDH microsphere was prepared using sulfonated polystyrene beads. Controllable morphology of LDH shell sphere is achieved readily by varying preparation conditions such as aging durations and temperatures. Removal toxical heavy metal anion was further investigation with the as-prepared flower-like MgAl-LDH microsphere.2. IBU drug molecule containing MgAl-LDHs@sPS microsphere was prepared with Fe3O4 magnetic core. Evluation of drug releasing shows that the release of IBU in PBS (pH=6.8) is increased with the increasing releasing time and gradually reachs the balance. 3. Using SiO2 as the template, MgAl-LDHs@SiO2 compostie microsphere was synthesized using a scalable procedure. The dimentional size and layer metal types were tuned on the basis of the flexibility to vary LDH composition.