Template sol-gel synthesis for fabrication of mesoporous silica/alumina hybrid membrane nanocomposites

Abstract

Mesoporous silica with high surface area and uniform channel distribution has been developed via liquid crystal templating materials such as amphiphilic triphenylene derivatives capable of having anisotropic and spontaneous alignment. However, amphiphilic triphenylene was only reported as a template to synthesize mesoporous silica nanocomposite with parallel structure to the substrate. Therefore, by introducing a one-dimensional (1D) template-limiting material such as porous alumina membrane, it was expected that the resulting hybrid membrane would give vertically alignment of self-assembled organic compounds to give high performance of nanocomposites for potential application in energy devices. Herein we report that mesoporous silica/alumina hybrid membrane with interpore distance of 2.5 nm was successfully fabricated by an amphiphilic triphenylene (TPC10TEG) as a template in sol-gel synthesis of mesoporous silica (TPC10TEG/silicahex) in the anodized alumina membrane (AAO). TPC10TEG/silicahex showed an anisotropic - based on presence of absorption peak at 264 nm. In addition, the hexagonal arrangement of TPC10TEG/silicahex was proved based on their transmission electron microscope (TEM) images and diffraction peaks of d100 and d200 at 2 = 2.52° and 5.04°, respectively. For fabrication of mesoporous silica/alumina hybrid membrane, simple approach of using vacuum or gravitational filtration was used for immobilization of TPC10TEG/silicahex to AAO membrane. X-ray diffraction (XRD) analysis on the resulting hybrid nanocomposite showed that the diffraction peaks of d100 and d200 of TPC10TEG/silicahex were still preserved, indicating that the hexagonal arrangements of mesoporous silica were maintained even after the fabrication. Likewise, the morphology study of the resulting hybrid membrane using TEM, scanning electron microscope (SEM), and field emission scanning electron microscope (FESEM) will be carried out and the results will be discussed later.