Preparation And Characterization Of Nanometer-sized α-Al₂O₃ Powders And The Study On Modification Of Polypropylenes With The Nanoparticles

Firstly this paper summarizes the current status of nanomaterial applications and opportunities opened by nanotechnology to many fields , such as new materials ,environmental protection,energy,health care,IT and other traditional industries that need upgrade their products. The preparation of ultrafine alumina powder is of far reaching importance to the development of electronic and material industry. The properties, applications and research situation, and preparation method of nanometer alumina at home and abroad has been presented in this paper. And the modification of polypropylenes with the nanoparticles is studied on. Nanometer-sized α-Al2O3 powders were prepared with inorganic aluminium salt as raw material by solid-phase method, wet-chemical method and mechanical chemical synthesis that lies between solid phase and wet phase. The powders are less aggregation and smaller sizes of particles. XRD analysis showed that the powders wereα-phase and belong to hexagonal system. The sizes of the particles were observed about 30～40 nm through TEM analysis and their shapes were ball-like. The following three kinds methods of preparation: solid-phase method,wet-chemical method and mechanical chemical synthesis are studied in this paper. The results show that all of them have little different effect on the crystalline size of ultrafine powder of α-Al2O3, but they have greatly different effect on scattered degree of their particles. The three methods can all prepare nanocrystalline α-Al2O3 powders with extremely small cryslallite size (30～40nm) and, moreover, the particles are less aggregation and dispersed evenly. Especially the mechanical chemical synthesis, it is a new type method that lies between solid-phase and wet-phase methods. Compared with the two methods, the mechanical chemical method has many advantages of simple process, low cost of production, stable quality of product, high purity and so on. So it is suited for industrial produce. The optimum technic conditions have been gotten in preparing high dispersive ammonium aluminum carbonate hydroxide (AACH) precursor by controlling reactant...