Templating Behavior of a Long-Chain Ionic Liquid in the Hydrothermal Synthesis of Mesoporous Silica

Abstract

The long-chain ionic liquid (IL) 1-hexadecyl-3-methylimidazolium chloride (C(16)mimCl) was used as a template to prepare porous silica with a two-dimensional hexagonal p6mm mesopore structure (MCM-41-type) as well as with a cubic Ia3d (gyroid, MCM-48-type structure) framework in basic synthesis medium via a hydrothermal synthesis procedure. A systematic study was carried out addressing the influence of the relative concentration of the IL and the pH on the mesostructure. As a main result, the IL template shows a broad range of conditions that allow the synthesis of the gyroid mesostructure with improved reproducibility. Unexpectedly, the formation of the hexagonal phase is less favorable, as the latter is quite sensitive to variations in parameters. This preference for the bicontinuous structure can be attributed to the special headgroup packing of ILs containing imidazolium groups.

Ionic Liquids as Surfactants – Applications as Demulsifiers of Petroleum Emulsions

“…ILs have also been widely explored as potential ionic surfactants with different areas and applications such as extraction of organic compounds, metal ions and radioactive isotopes [55][56], as template to produce micro/mesoporous materials [57][58], in microemulsion [59][60][61]. The surfactant properties of ILs are easily understood if we consider that these compounds generally have a well-defined structure with hydrophilic character and another with hydrophobic character, i.e.…”

Monodispersed mesoporous silica nanospheres based on pyridinium ionic liquids

“…Long chain imidazolium ILs are of particular interest due to its tendency to self-assemble which is preferred in developing ordered mesoporous materials [30]. A series of 1-alkyl-3-methylimidazolium chloride (C n MimCl where n = 10, 14, 16 and 18) were used to prepare highly ordered lamellar silica via nanocasting technique and the developed silica exhibited microporosity [31].…”

“…A series of 1-alkyl-3-methylimidazolium chloride (C n MimCl where n = 10, 14, 16 and 18) were used to prepare highly ordered lamellar silica via nanocasting technique and the developed silica exhibited microporosity [31]. Wang et al used 1-hexadecyl-3-methylimidazolium chloride to develop ordered mesoporous silica, MCM-41 and MCM-48 via hydrothermal method [30]. Development of mesoporous silica is not limited to long chain imidazolium based ILs.…”

The ionic liquid [Bmim][FeCl₄] catalyzes the formation of iron doped mesoporous silica aerogels for H₂O₂ decomposition

“…The current work focuses on the question whether [Bmim] [FeCl 4 ] can act as an ILP for the synthesis of a transition metal containing mesoporous silica material. It has also been demonstrated that ILs are efficient tools for the design of mesoporous silica [22] [23] [24] [25] [26]. As a result, we wondered if a suitable IL may (i) catalyze the hydrolysis of appropriate silanes to form a mesoporous matrix and (ii) at the same time serve as the metal source for the formation of catalytically active metal species within the SiO 2 network.…”