Fabrication of Cactus Rod-like Mesoporous Alumina with Ionic Liquid-Supramolecular Gelator as Cotemplate

Abstract

An amino acid ionic liquid tetramethylammonium glycinate ([N1111]­[Gly]) and an organic supramolecular gelator N-lauroyl-l-glutamic acid di-n-butylamide (GP-1) were used as structure-directing agents for the fabrication of mesoporous alumina with diverse morphologies via a solvothermal synthetic method. The irregular sheets and hierarchical clusters were respectively prepared with only [N1111]­[Gly] or GP-1/EW as the template, whereas a distinct cactus rod-like morphology with interlaced lateral plates was constructed with [N1111]­[Gly] and GP-1 as the cotemplate. The cotemplate synergistic effects of [N1111]­[Gly] and GP-1 on the morphology tailoring of alumina have been investigated in depth. A self-assembly mechanism based on the bilayer arrangement model was proposed to be responsible for the formation of final cactus rod-like alumina. The intermolecular H-bonds between the GP-1 molecule and [N1111]­[Gly]-AlOOH hybrids was found to be the main driving force for the axial growth of initial nanocrystals, and the growth of the nanocrystals in lateral orientation was inhibited due to the stereohindrance effect of [N1111]­[Gly].

Supramolecular Gel as the Template for Catalysis, Inorganic Superstructure, and Pharmaceutical Crystallization

“…In another interesting example, a combination of an amino acid ionic liquid tetramethylammonium glycinate and gelator 42 were used as a templating agent for the fabrication of mesoporous alumina with diverse morphologies via a solvothermal synthetic method [90]. While ionic liquid only and gelator only systems resulted in irregular sheets and hierarchical clusters, a distinct cactus rod-like morphology with interlaced lateral plates was constructed using the combination of two.…”

Solvothermal Synthesis of Spherical Alumina: Delving into the Formation Mechanism and Morphological Change with Phase Transformation

“…have been reported to date. [9][10][11][12][13][14] For the synthesis of porous alumina, different methods like solgel, [15] evaporation induced self-assembly (EISA), [16] spray pyrolysis, [17] hard templating route using carbon [18] have already been reported. Wu et al synthesized mesoporous alumina by reverse precipitation method.…”

“…Different morphologies of alumina such as nanorod, nanofibre, petal‐like nanoflake, nanoflower, cactus‐like morphology etc. have been reported to date [9–14] . For the synthesis of porous alumina, different methods like sol‐gel, [15] evaporation induced self‐assembly (EISA), [16] spray pyrolysis, [17] hard templating route using carbon [18] have already been reported.…”