Mixed surfactant systems have the potential to impart controlled combinations of functionality and pore structure to mesoporous metal oxides. Here, we combine a functional glucopyranoside surfactant with a cationic surfactant that readily forms liquid crystalline mesophases. The phase diagram for the ternary system CTAB/H2O/n-octyl-β-d-glucopyranoside (C8G1) at 50 °C is measured using polarized optical microscopy. At this temperature, the binary C8G1/H2O system forms disordered micellar solutions up to 72 wt% C8G1, and there is no hexagonal phase. With the addition of CTAB, we identify a large area of hexagonal phase, as well as cubic, lamellar and solid surfactant phases. The ternary phase diagram is used to predict the synthesis of thick mesoporous silica films via a direct liquid crystal templating technique. By changing the relative concentration of mixed surfactants as well as inorganic precursor species, surfactant/silica mesostructured thick films can be synthesized with variable glucopyranoside content, and with 2D hexagonal, cubic and lamellar structures. The domains over which different mesophases are prepared correspond well with those of the ternary phase diagram if the hydrophilic inorganic species is assumed to act as an equivalent volume of water.
|Number of pages||9|
|Journal||Journal of Colloid and Interface Science|
|State||Published - Dec 15 2007|
Bibliographical noteFunding Information:
This work is based upon work partially supported by the National Science Foundation under Grant Nos. DMR-0210517, CTS-0348234, and EAR-0521405. We thank Dr. Alan Dozier for assistance with the TEM imaging and Prof. Kimberly Anderson for allowing access to the optical microscope.
- Liquid crystal
- Mixed surfactants
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films
- Colloid and Surface Chemistry