Akihiro Okabe

A simple route to bimodal mesoporous silica via tetrafluoroborate ion-mediated hydrophobic transformation of template micellar surface

Addition of NaBF4 to an aqueous solution of an onium ion surfactant results in the in situ generation of large aggregates of micelles, which template the formation of secondary pores in the sol-gel synthesis of mesoporous silica.

High-density modification of mesoporous silica inner walls with amino acid function by residue transfer from template

Abstract Novel surfactants containing an alkoxysilane group and an amino acid residue have been synthesized. Using these surfactants as templates, mesoporous silica/surfactant covalent-composites were prepared. Selective removal of the alkyl chain of the template provided mesoporous silica with inner surface densely covered by the amino acid residue. Successful modification process was confirmed by XRD, FT-IR, TEM and TGA analyses.

Proteosilica - mesoporous silicates densely filling amino acid and peptide assemblies in their nanoscale pores

Abstract In order to prepare protein-like structure in inorganic mesostructured framework, methodologies to densely fill assemblies of amino acids and peptides in mesoporous silica (Proteosilica) are proposed in this study. Surfactants having a peptide residue with hydrophobic chain at C-terminal and polar group at N-terminal were newly synthesized, and mesoporous silicates in both powder and film forms were successfully prepared with these templates. Especially a spin-coating method effectively provided transparent mesoporous films, and formation of regular structures significantly depends on hydrogen bonding formed between the peptide moieties.

Ethanol vapor-mediated maturing for the enhancement of structural regularity of hexagonal mesoporous silica films

Structural regularity of hexagonal mesoporous silica films is dramatically enhanced when allowed to stand for a few hours in an ethanol vapor-containing closed bottle before dryness.

Nanostructured silicate film templated by discotic CT-complex column

Abstract Nanostructured silicate films were prepared using charge-transfer (CT) complexes composed of a triphenylene-based disk-like molecule as templates. A triphenylene derivative having hydrophilic triethyleneglycol groups was newly synthesized as an electron donor that can form CT complexes with various kinds of electron acceptors, and transparent nanostructured silicate films were obtained with these CT complexes by various coating techniques, i.e., spin-coating, dip-coating and casting. The CT columns immobilized in the mesopores are stable against external perturbation, and possibly have long-range structural ordering.