利用纳米碳酸钙为模板制备二氧化硅空心微球

Preparation of Hollow Silica Microspheres Using Nano CalciumCarbonate as Template

二氧化硅空心微球因在催化、生物分子包裹、药物缓释和基因传输方面具有潜在的重要应用,而受到了研究人员的广泛关注。本研究以自制纳米碳酸钙作为模板,正硅酸乙酯为硅源,制备了结构完整的二氧化硅空心微球。结果表明:浓度为0.15%的氢氧化钙溶液制备的纳米碳酸钙具有完整的球形结构,随氢氧化钙浓度的提高,碳酸钙由球形结构开始转变为方解石晶体形式的块状或纤维状结构。正硅酸乙酯作为硅源通过水解作用形成单体,调节pH值可使得水解产物在纳米碳酸钙模板上成核生长并通过缩聚反应形成三维网络骨架,在去除模板和干燥后可得到结构完好的二氧化硅空心微球。

Silica hollow microspheres have received extensive attention from researchers because of their potentially important applications in catalysis,biomolecular packaging,drug delivery,and gene delivery.In this study,self-made nano-calcium carbonate was used as a template,and ethyl orthosilicate was used as a silicon source to prepare hollow silica microspheres with complete structure.The results showed that the nano-calcium carbonate prepared with a calcium hydroxide solution of 0.15%concentration had complete spherical structure,with the increase of cal-cium hydroxide concentration,calcium carbonate begins to transform from spherical structure to massive or fibrous structure in the form of calcite crystals.Ethyl orthosilicate is used as a silicon source to form monomers through hydrolysis.Adjusting the pH value allows the hydrolysate to nucleate and grow on the nano-calcium carbonate template and form a three-dimensional network skeleton through polycondensation.After removing the template and drying,the structure is intact hollow silica microspheres.