| Functional core-shell mesoporous composites are in demand due to the rapid development of nanotechnology.The shell is modified to achieve surface functionalized and multi-component,which are widely used in the fields of energy,biological therapy and adsorption.The SiO2-like hard shells in most core-shell materials limit its wide range of applications.The multi-step synthesis followed by surface modification makes the steps more tedious.Therefore,flexible polymer shells became research objects,and different structures of flexible core-shell materials were synthesized in a controlled manner and used as heterogeneous catalysts and photothermal agents.The main studies are as follows.1.Yolk-shell magnetic mesoporous polydopamine microspheres（Yolk-shell magnetic mPDA）were prepared via interfacial assembly of microemulsions combined with selective etching strategy.The obtained Fe3O4@Void@mPDA microspheres have a clearly visible sandwich structure with a magnetite core inside and vertical pore channels uniformly distributed on the mesoporous PDA shell,with cavities between them.The interlayer cavities and the mesoporous PDA shell can be tuned by the amount of tetraethyl orthosilicate（TEOS）and dopamine（DA）.After removal of the template agent,radial pore size of 5.2 nm,large intermediate cavity of 80 nm,high specific surface area of 303.3 m2 g-1,and large pore volume of 0.2 cm3 g-1 were obtained.Owing to the inherent photothermal properties and biocompatibility of Fe3O4 and PDA,Fe3O4@Void@mPDA microspheres exhibited good photothermal anti-tumor cell capability.By hightemperature treatment,the derived magnetic mesoporous carbon microspheres can stably trap and disperse Au nanoparticles and serve as heterogeneous catalyst for the hydrogenation of 4-nitrophenol with high catalytic activity,rapid magnetic separation and catalyst recyclability.2.Amphiphilic copolymer directed interfacial polymerization and selective etching methods were used to prepare core-shell and hollow structure mPDA microspheres.SiO2@mPDA microspheres have regular core-shell structure with a SiO2 core,uniformly distributed with radially arranged pore channels,and clear boundary between the shell and core.SiO2 core and mPDA shell thickness can be adjusted by the amount of TEOS and DA.Then,the hollow mesoporous polydopamine structure was obtained by etching.The core size is adjustable in the range of 100 nm-150 nm,and the mesoporous layer is adjustable in the thickness range of 20 nm-100 nm.Due to a series of advantages such as rich nitrogen-containing groups of polydopamine,good photothermal properties and water solubility as well as the regular pore structure of the mesoporous structure,the material dispilays the ability of drug loading and excellent photothermal absorption,and shows good photothermal properties before and after drug loading,as well as better effect on the ability to fight against tumor cells in a photothermal synergistic drug delivery treatment. |
