Synthesis of Mesoporous Silica Materials by Using Anionic Surfactants as Template

Abstract

Mesoporous materials have attracted a great deal of attention because of their controllable structures and compositions, which make them suitable for a wide range of applications in catalysis, environmental clean-up, and development of advanced materials. Various mesoporous materials can be synthesized based on the self-assembly of surfactants and inorganic precursors. We previously demonstrated a novel templating route for preparing mesoporous silicas based on the self-assembly of anionic surfactants and inorganic precursors in the presence of aminosilane or quaternized aminosilane as a co-structure-directing agent (CSDA). We continue to investigate the resultant novel mesoporous materials called anionic surfactant mesoporous silica (AMS). The latest AMS series is a novel bicontinuous cubic Pn3 m mesoporous silica (AMS-10). We have also found that the assynthesized AMS is transformed into amino-functionalized mesoporous silica, by removal of only the surfactant by extraction, with potential uses as high-performance catalysts and adsorbents. Furthermore, the use of a chiral anionic surfactant derived from the amino acid, N-myristoyl-N-myristoyl-N l-alanine sodium salt, provides chiral mesoporous silica. Such anionic surfactant templating routes will provide a new family of mesoporous materials as well as information on the structural behavior of anionic surfactants. This review describes the preparation, properties, and potential applications of anionic surfactant templated mesoporous silicas.

A Waste‐Derived Biosurfactant for the Preparation of Templated Silica Powders

“…To solve this problem, a mixture of TEOS and 3-aminopropyltriethoxysilane (APS) were chosen as the silica source. [35] These reagents allowed the reaction to proceed at pH 5 with the surfactant in solution and the APS amino groups still positively charged (I + ). Thus, the silica interaction with the surfactant carboxylate (COO À ) functional groups could occur.…”

“…Thus, the silica interaction with the surfactant carboxylate (COO À ) functional groups could occur. Under these conditions the sol-gel reaction could take place with the APS precursor held to the BS110 molecules by a S À I + type electrostatic interaction [35] and the formation of the silica network was likely to follow the shape of the biosurfactant molecules or aggregates.…”

Twisted and tubular silica structures by anionic surfactant fibers encapsulation

“…Anionic surfactant N-miristoyl-L-alanine (C 14 -L-AlaA) was synthesized by acylation of L-alanine with myristoyl chloride, as reported before [26,29] with slight adjustment. The starting materials were purchased from SIGMA-ALDRICH-FLUKA.…”

“…Chiral anionic surfactants were used for fabrication of rod-like mesoporous chiral silica structures during the last decade [3,6,8,20,[23][24][25][26]. In order to fabricate chiral silica structures, we used C 14 -L-AlaA chiral anionic surfactant.…”

“…The alkoxysilane groups of the CSDA further condensate by covalent interaction with silica precursor. The condensed inorganic phase is formed by the solidification of primary micellar rods and later their packing into twisted or helical rod-like silica structures [3,6,8,20,[23][24][25][26][27].…”