Synthesis of Mesoporous Silica Nanofibers with Controlled Pore Architectures
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- 作者：Jianfang Wang ; Chia-Kuang Tsung ; Wenbin Hong ; Yiying Wu ; Jing Tang ; and Galen D. Stucky
- 刊名：Chemistry of Materials
- 出版年：2004
- 出版时间：November 30, 2004
- 年：2004
- 卷：16
- 期：24
- 页码：5169 - 5181
- 全文大小：1537K
- 年卷期：v.16,no.24(November 30, 2004)
- ISSN：1520-5002
文摘
A one-phase route has been developed for the synthesis, under strongly acidic conditionswith cationic surfactants, of mesoporous silica nanofibers with controlled internal porearchitectures. The diameters of the fibers range from 50 to 250 nm, and the lengths are upto millimeters. The nanofibers can have either a longitudinal pore architecture, in whichthe pore channels are aligned parallel to the fiber axis, or a circular pore architecture, inwhich the pore channels are wound circularly around the fiber axis. The pore channels inboth types of nanofibers are hexagonally packed. The cross sections of the nanofibers withlongitudinal pore architectures are hexagonal and those of the nanofibers with circular porearchitectures are circular. Systematic experiments were carried out in which the fraction ofthe nanofibers with circular pore architectures among the overall nanofibers was determinedas a function of the growth temperature for hexadecyltrimethylammonium chloride (C16TMAC), hexadecyltrimethylammonium bromide (C16TMAB), hexadecylpyridinium chloride(C16PC), and hexadecylpyridinium bromide (C16PB) surfactants. Generally, lower temperatures produce nanofibers with longitudinal pore architectures and higher temperaturesproduce nanofibers with circular pore architectures. The transition temperatures for C16TMAC and C16TMAB surfactants are around 75 
C and those for C16PC and C16PBsurfactants are around 55 C. In addition, the one-phase synthesis was carried out withcationic surfactants of different tail lengths, including dodecyltrimethylammonium bromide(C12TMAB), tetradecyltrimethylammonium bromide (C14TMAB), and octadecyltrimethylammonium bromide (C18TMAB). No nanofibers are obtained from the synthesis with C12TMABor C14TMAB surfactants, while greater than 95 wt % of the products from the synthesiswith C18TMAB surfactant are nanofibers with longitudinal pore architectures in thetemperature range of 40-90 C. Furthermore, rhodamine 6G (Rh6G) dye molecules wereincorporated during growth to make mesostructured nanofibers that are millimeters longand fluoresce uniformly along the entire length of the individual fiber.
C and those for C16PC and C16PBsurfactants are around 55 C. In addition, the one-phase synthesis was carried out withcationic surfactants of different tail lengths, including dodecyltrimethylammonium bromide(C12TMAB), tetradecyltrimethylammonium bromide (C14TMAB), and octadecyltrimethylammonium bromide (C18TMAB). No nanofibers are obtained from the synthesis with C12TMABor C14TMAB surfactants, while greater than 95 wt % of the products from the synthesiswith C18TMAB surfactant are nanofibers with longitudinal pore architectures in thetemperature range of 40-90 C. Furthermore, rhodamine 6G (Rh6G) dye molecules wereincorporated during growth to make mesostructured nanofibers that are millimeters longand fluoresce uniformly along the entire length of the individual fiber.