有序介孔炭分子筛膜的制备与表征

Preparation and Characterization of Ordered Mesoporous Carbon Membranes

以三嵌段共聚物P123为结构导向剂和有机碳源,正硅酸乙酯为无机前驱体,在微量酸的催化条件下,结合非水体系蒸发诱导自组装技术与溶胶-凝胶工艺,采用浸渍-提拉法制备了介孔炭分子筛膜,研究了陈化温度对介孔炭膜结构的影响。通过透射电镜(TEM)、N2物理吸附-脱附、场发射扫描电镜(FESEM)和热重分析(TGA)对膜体的形貌结构性能进行了表征。结果表明,P123是优良的制膜材料,硫酸的预处理提高了P123的碳转化率,是成膜的关键因素之一。所制备的膜体材料由一定取向的类碳纳米管阵列组成;膜体表面致密、光滑无裂纹,具有孔径均一的对称结构。同时可以通过改变涂膜液的陈化温度来调节炭分子筛膜的孔径大小。

Novel carbon membranes with a hexagonal structure were fabricated directly by the carbonization of sulfuric-acid-treated surfactant/silica nanocomposite membranes and subsequent silica removal. The nanocomposite membranes were prepared by dip coating technique through a combination of sol-gel and evaporation-induced self-assembly process. The samples were characterized by field emission scanning electron microscopy （FESEM）, transmission electron microscopy （TEM）, N2 adsorption-desorption, and thermogravimetric analysis （TGA）. These analyses reveal that the carbon membranes are composed of carbon nanotubes arrays and have continuous, smooth and ordered symmetric structure. The surfactant triblock copolymer P123 has dual functions in the sol-gel process. One is the structure directing and the other is carbon precursor. Pretreatment with sulfuric acid is a key step to improve the carbon yield of P123 and to stabilize the structure of carbon membranes. At the same time, by varying the aging temperature of nanocomposite membrane, it is possible to control the size of ordered carbon membrane.