以卵磷脂为手性添加剂制备手性介孔二氧化硅

Preparation of Chiral Mesoporous Silica Using Phosphatidylcholine as a Chiral Additive

以十六烷基三甲基溴化铵(CTAB)的自组装体为模板,卵磷脂(PC)为手性添加剂,在n PC∶nCTAB=1∶21时,通过溶胶-凝胶法制备了螺旋介孔二氧化硅纳米棒。利用扫描电镜(FESEM)、透射电镜(TEM)、X-射线衍射以及氮气吸附-脱附等测试手段,对该纳米棒的形貌以及孔结构进行了表征。TEM显示该纳米棒的长度约为50～200 nm,直径约为30～50 nm。X-射线衍射表明孔道呈二维六方排列,虽然FESEM显示纳米棒左右手比例约为1∶1,但通过圆二色谱表征证明该纳米棒在埃尺度下倾向于形成单一手性。结果表明,卵磷脂的手性可以传递到螺旋介孔二氧化硅纳米棒中。

Helical mesoporous silica nanorods were prepared through a so-gel approach using cetyhrimethylammonium bromide （CTAB） as the template and phosphatidylcholine （PC） as a chiral additive. The molar ratio of PC and CTAB is 1：21. The morphologies and pore architectures were characterized using field emission scanning electron microscopy （FESEM）, transmission electron microscopy （TEM）, N2 sorptions and X-ray diffraction. It was found that the mesoporous silica nanorods were about 30~50 nm in diameter and about 50~200 nm in length. The TEM images and the small-angle X-diffraction indicated that the pore channels arranged in a two-dimensional hexagonal structure. The FESEM images indicated that the ratio of the left- and right-handed nanorods is almost 1：1. However, the circular dichroism spectrum （CD） indicated that the nanorods tended to form a structure with homochirality at angstrom level. It seems that the chirality of PC has been successfully transferred to the walls of the helical mesoporous silica nanorods.