纳米技术合成硅酸三钙及表征

以硅溶胶、硝酸钙为原料，尿素为燃料，采用燃烧法制备纳米硅酸三钙。研究了化学计量比、引燃温度对合成产物中游离氧化钙含量的影响。用乙二醇法测定产物中游离氧化钙的含量，x射线衍射仪、场发射扫描电镜、Zeta电位及纳米粒度分析仪和微量热仪表征合成样品的物相、微观形貌、粒度分布和水化热。结果表明：化学计量比为0．24，引燃温度为700oC时，合成产物中游离氧化钙含量达到最低值2．0％；合成的纳米硅酸三钙颗粒为不同结晶程度且呈现多种形貌的颗粒，平均粒度为225．9nm；合成的纳米硅酸三钙水化放热峰值出现的时间为69．2s，峰值为2．4368mw／g，比传统水泥具有较高的水化活性。

Synthesis and Characterization of Tricalcium Silicate by Nanotechnology Route

Nano tricalcium silicate （nano- C3S） was synthesized by a combustion method with silica sol and calcium nitrate as raw materials ,urea as fuel. Effects of stoichiometric ratio and ignition temperature on the content of f-CaO in synthesized nano- C3 S were investigated. The content of f-CaO in synthesized samples was measured by glycol method. The phase composition, microstructure , particle size distribution and hydration heat of samples were charac- terized by X-ray diffractometer （XRD） ,Field emission scanning electron microscope （FSEM） ,Zeta potential/sub- micron size analyzer and Digital display calorimeter. The results show that the content of f-CaO in the sample reaches the least value about 2.0% under the synthesized condition of stoichiometric ratio at 0.24 and the ignition temperature at 700 ℃. The synthesized nano- C3 S particles show various morphology and diverse degree of crystallization with an average particle＇ size of 225.9nm. The synthesized nano- C3S shows a higher hydration reactivity in comparision with traditional cement because the value of the heat evolution peak of the product is 2. 4368 mw/g at a hydration time of 69.2 seconds.