| The properties, applications and research situation at home and abroad of nanometer magnesia have been presented in this thesis. From the aspects of colloid stable mechanism, factors influencing the quality of final nanometer magnesia product during preparation process in Precipitation-Transforming-Method were systematically analyzed. Technical skills of nanometer magnesia preparation which used tetramethyl ammonium bromide as additives was first put forward and researched by the author, and then on the base of small-scale experiments results, amplifying experiments of nanometer magnesia preparation was researched. Normal working intervals of rotating speed and optimal rotating speed was decided. The results shows:(1) Technical skills of nanometer magnesia preparation which used magnesium chloride and sodium carbonate as raw materials and used tetramethyl ammonium bromide as additives is feasible. The optimal preparation conditions as follows: the dosage of tetramethyl ammonium bromide is 0.5g, reaction time is 20min, reaction temperature is 30℃, the mixing style of raw materials is instantaneous, maturing time is 30min, the drying time in microwave oven is 10min, the calcination is at 550℃for 150min. The average particle size of final nanometer magnesia product is 7nm.(2) On the base of small-scale experiments results, amplifying experiments of nanometer magnesia preparation chose Central Tornado Flow Stirring Vessel as reaction vessel. Normal working intervals of rotating speed is 300r/min, and optimal rotating speed is 310r/min, and the average particle size of final nanometer magnesia product is 6.28nm, and useable agitating valve diameter can vary between 49.5mm and 73.5mm in the range of normal working interval.(3) Oscillating flask method was used to test the antibacterial effect of as-synthesized nanometer magnesia samples, the results shows that as-synthesized nanometer magnesia samples has good antibacterial effects against Candida albicans and staphylococcus aureus. |
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