用乙酰胺合成六方形貌介孔氧化硅纤维

Synthesis of Mesoporous Silica Fibers with Hexagonal Appearance

以正硅酸乙酯（TEOS）为硅前驱体,乙酰胺（CH3CONH2）为助溶剂,十六烷基氯化吡啶（C16PyC l）为结构导向剂,在酸性溶液中合成六方形貌的介孔氧化硅纤维,经小角X射线衍射（SXRD）、扫描电子显微镜（SEM）和低温N2吸附-脱附技术等表征。结果表明：合成的样品为六角状外形的氧化硅纤维,直径约47μm,长度约几十微米。六角状纤维的孔道具有与MCM-41类似的六方结构;煅烧后样品的吸附数据显示出吸附-脱附等温线为典型的IV型,吸附-脱附滞后环为H2型,孔道的孔径分布较宽;BJH最可几孔径为2.96 nm和3.50 nm,表明样品具有特殊的双孔道结构;计算的BET表面积为1 060 m2.g-1。

Hexagonal silica fibers with bimodal mesopore structure were synthesized in acidic solution by using tetraethyl orthosilicate（TEOS） as silica precursor,acetamide（CH3CONH2） as cosolvent,and cetylpyridinium chloride（C16PyCl） as template.Small angle X-ray diffraction（SXRD）,scanning electron microscope（SEM）,and nitrogen adsorption-desorption techniques were used to characterize the samples.Results demonstrate that the synthesized is hexagonal-appearance fibers with diameters of 4～7 μm and lengths of several tens of millimeters,with pores having hexagonal meso-structure analogous to MCM-41;there exists a type IV adsorption-desorption isotherm and an H2 hysteresis loop in N2 adsorption-desorption curves;the most probable pore diameter（using BJH method） is 2.96/3.50 nm,which means the samples have bimodal structure.The calculated BET surface area of the materials is 1 060 m2·g-1.