| In recent years, template approaches on the preparation of nano-structured materials with complex morphology and structure enjoy great popularity in academia and industry. The template method is superior to other approaches, which the size, structure and morphology of the prepared materials can be controlled and adjusted by simple altering the nature of the template and the preparation conditions. Moreover, template can be pre-designed according to the size and shape of objective materials.Microgels are cross-linked latex particles with narrow size distribution and the inherent steric stability. The microgels of close monodispersity with different volume and cross-linking density can be prepared by using an inverse emulsion polymerization method. Both artificial and natural materials, including zeolites, membranes, vesicles, liquid crystal, microemulsion, micelles, biopolymers, etc., have been used as template. The three-dimentional network structure and spherical morphology of polymeric microgels may guarantee the homogeneous of the structure of the composite, the size and the morphology of the various organic-inorganic composites with unusual structures. Compared with other template, especially organic templates, the types of functional groups, the size, the composition, and even cross-linking density of microgels are easily controlled. Therefore, polymeric microgels are ideal templates for preparing nano-structured spherical organic-inorganic composites.Poly(methacrylic acid) (MAA) and poly(acrylic acid) (AA) microgels have been prepared as templates by employing inverse emulsion polymerization techniques. Four types of spherical organic-inorganic nano-composites have been prepared by introduction of precipitation agent into the PMAA/PAA microgels containing appropriate rate metal ions. They are poly(sodium methacrylate)/CdS (PMAANa/CdS), PMAANa/PbS, poly(sodium acrylate)/La(OH)3 (PAANa/La(OH)3) and PAANa/PbS, respectively.(1) Preparation and properties of PMAANa/CdS composite particlesPMAANa microgels containing Cd2+ were prepared by inverse emulsion polymerization method. Then,H2S gas was introduced slowly into the system, and themetal ions were deposited within the microgels as CdS. The morphology, composition and crystalline of the composite particles were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA) techniques. It has been demonstrated that it is the microgel that guaranteed the homogeneous of the structure of the composite, the size and the morphology of the composite particles. The surface structure of the micro-particles can be adjusted by changing the preparing conditions. The composites may adopt hollow sphere structure, and the inner may lack of CdS due to precipitation was started from the outer part of the microgels. The inorganic CdS in the composite is about 20%, and the crystalline structure of CdS in the composite is of face-centered structure. Furthermore, the spherical composites are of photoluminescence properties because of the presence of CdS. In addition, both the rigidity of inorganic compounds and the flexibility of polymeric compounds can be found in the composite.In addition, the effects of intense shear forces of ultrasound make the surface of particles much more smooth. Therefore, this uniform surface may be expected to provide an idea substrate for functional modification.(2) Preparation and properties of PMAANa/PbS composite particlesThe spherical PMAANa/PbS composites with core-shell structures were prepared by polymeric microgel template method. It was found that the surface structure of the microgels largely depends upon the nature of the continuous phase of the system. For xylene, the micro-particles have a fishnet-like surface structure, and the inner part of the particles is different from outer part in structure and composition. The surface of the particles, however, from cyclohexane looks more smooth and denser than that of the particles from xylene. In addition,...
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