Large-scale And General Template Method For Formation Metal Oxide Hollow Microsphere With Application Performance

Due to the special structure and morphology of hollow microspheres,they have low density, high surface area, thermal insulation, high stability, surface permeability and light scattering properties, and the hollow microspheres as a new functional material have wide application prospect and special in piezoelectric conversion, catalysis, materials science and other fields. Metal oxide nanomaterials have a wide range of uses with special physical and chemical properties in the electronics industry, ceramic industry, aerospace industry and other fields. Metal oxide hollow microspheres have become a hot research object in high technology, and there are many kinds of the preparation method, template method is the most widely used, because as long as we find a suitable template material in theory, hollow structure can be prepared with a controllable of size, shape and chemical group. But there are defects in the template method preparation metal oxide hollow microspheres, such as needing template modification, a sensitive solution environment such as pH, ionic strength for soft template method. There is not any experimental method of preparing metal oxide hollow microspheres with a common and large-scale method, and therefore, it is very valuable for studying the preparation of hollow microspheres with template method in-depth and detailed.This paper mainly study a variety of metal oxide hollow microsphere materials, combined with the hard template method, using distillation precipitation method, we prepared microspheres with containing carboxyl groups in surface and interior. Without furthering modification, it could form metal carboxylate precursor microspheres with various metal ions. And then tne microspheres can be transformed into metal oxide hollow microspheres with well morphology and large-scale production by solid phase synthesis method, and it could expand the general method for production mixed metal oxide hollow microspheres. The main contents of the work are as following:1) PEGDMA-co-MAA monodisperse crosslinked polymer microspheres were synthesized by distillation precipitation method, as a template, it could absorb Na+ in ethanol solution of sodium acetate, then the target metal ions(M+) replaced Na+ by cation exchange process, forming the M+-PEGDMA-co-MAA microsphere, The dried powder was calcined in tube furnace with air condition, controlling precisely the heating process, and obtained metal oxide hollow microspheres. Take tin ion for example, through trying the different valence states of the tin ion and different heating rate and other experimental conditions, we obtained a series of different diameters of SnO2 hollow microspheres. By field emission scanning electron microscopy(FESEM), transmission electron microscopy(TEM), thermal analysis system(TGA), X-ray diffraction(XRD) and other methods, the forming mechanism in calcination process was analyzed, and the Sn O2 hollow microspheres were used as anode materials for lithium ion batteries, assembled a simulated battery for electrochemical test. The results showed that the hollow microspheres of SnO2 anode material has a good charge and discharge capacity. This method is relatively simple, can be large-scale preparation, and also applied for other metal oxides, it has good practical significance for the preparation of metal oxide hollow microsphere, can become a widely used method.2) Disperse the PMAA microspheres into the ethylene glycol solution of acetic acid metal salts, we can get the mono-disperse PMAA-EG-M by heating reflux. Through the precise control of heating rate of calcinations to remove the PMAA core, we obtain a series of mono hollow metal oxides Zn O, Cu O, CoO2 and NiO2, binary hollow metal oxides NixCoyO2-x-y, ZnxCoyO2-x-y, ZnxCdyO2-x-y, CuxCoyO2-x-y nano-materials. The structure of the products were characterized by TEM and SEM, the components of the metal oxides before and after calcinations were confirmed by FT-IR and the crystal form after calcinations was tested by XRD. This method can prepare the mono-disperse precursor just by simple reflux and get the hollow multi-metal oxides by further precise control of heating rates. So this method is simple, tunable, easy to prepare large-scale, and versatile in preparing metal oxides hollow microspheres.