The synthesis of a core-shell hybrid composite micro-sphere with controllable homogenous or heterogeneous multi-shell structure by multiple-growth via a combination method

摘要

The preparation of controllable multi-shell nano and micro particles has great significance not only for their potential applications but also for fabricating novel composite functional advanced materials. In this paper, MSiO_2, MTiO_2 and SSiO_2 with good monodispersity and no agglomeration among spheres have been synthesized successfully based on St?ber's method. MSiO_2 were characterized as the silica with a worm-like mesopore structure and with uniform pore sizes of about 2.0 nm, and about 700 m~2/g of specific surface area. A core-shell hybrid composite micron-sized spherical particle with multi-shell structures by using the synthesized MSiO_2, MTiO_2 and SSiO_2 with a combination method has been designed and fabricated. The multiple-layers of these spherical particles can be controllably prepared via multiple deposits in an alcohol solution system, and the standard deviations of particle size of each sample are less than 3%. The temperature and the seeds mass effect on the morphologies of MSiO_2/SSiO_2 and MSiO_2/SSiO_2/SSiO_2 via multiple-growth by coating solid silica layers have been investigated. In order to illustrate the sphere with multi-shell structure may have multi-functionalized, the MSiO_2 sphere embedded methylene blue in the pores and coated with solid silica shell was fabricated.