合成条件对介孔氧化硅材料孔径尺寸的影响

分别在室温酸性、室温碱性、水热碱性条件下合成了介孔氧化硅材料MCM－41，通过XRD，HRTEM，氮气吸附等手段对介孔氧化硅材料进行了表征，并探讨了3种条件下材料介孔尺寸的变化。结果表明：室温酸性条件下合成的MCM－41材料具有最小的介孔尺寸，碱性条件则有利于合成较大孔径的样品。另外还发现无机盐离子的添加、反应温度的变化及煅烧过程均可以影响介孔尺寸，并提出了无机盐离子通过影响表面活性剂胶团的荷电性质和尺寸而改变材料孔径尺寸的模型。

EFFECT OF SYNTHETIC CONDITIONS ON THE PORE SIZE OF MESOPOROUS SILICA MATERIALS

The mesoporous silica materials, MCM-41, with controlled pore size were synthesized under acidic, basic conditions at room temperature and hydrothermal basic condition.The characteristics of samples were investigated using XRD, HRTEM, and N 2 adsorption techniques. It shows that pore size of the samples synthesized in acidic medium is the smallest, while that under the hydrothermal treatment in basic condition will be larger. In addition, the results indicate that the reaction temperature and calcination can also regulate the pore size of the samples. A model is proposed to explain the effect of inorganic counterions concentration on the surfactant micelles size, will lead to a more compressed electric double layer of surfactant and smaller micelles size, and finally smaller pores.