Kazuyuki Kuroda

Layered silicates, whose frameworks are composed of only SiO4 tetrahedra, provide many interesting properties through covalent modification of interlayer SiOH/SiO−groups. This review summarizes covalent modifications of layered silicates, such as magadiite, kanemite, kenyaite, layered octosilicate (RUB-18 or ilerite), and layered zeolitic materials (or their precursors). Interlayer silanol groups can be modified with various silylation reagents including alkyl, amino, and thiol groups. Anion exc

Colloidal mesoporous silica nanoparticles less than 20 nm in diameter are prepared by dialysis; this simple surfactant removal route can avoid aggregation by sedimentation-redispersion and remove cationic surfactants while retaining the original colloidal state, which is applicable to the preparation of primary nanoparticles carrying a functional organic substance.

Lamellar and hexagonal structures of new silica-based hybrids were directly formed from newly designed alkylsiloxane oligomers 1. This approach based on the self-assembly of single precursors provides a novel pathway to ordered microporous silica as well as mesostructured silica-based hybrid materials (see scheme, 1) hydrolysis and polycondensation, 2) self-assembly).

Exfoliated K4Nb6O17 bilayer nanosheets in extraordinarily large size (ca. 100 microns) were prepared by the direct reaction of K4Nb6O17.3H2O crystals with an aqueous solution of propylamine; the size was extremely larger than that of exfoliated nanosheets (several microns) reported previously.

We have investigated the structures of mesostructured (before calcination) and mesoporous (after calcination) silica thin films and replicated Pt nanowires by high-resolution scanning electron microscopy (HRSEM). Highly ordered lamellar, two-dimensional (2D) hexagonal, and three-dimensional (3D) hexagonal mesostructured/mesoporous silica thin films were synthesized by adjusting the concentration of triblock copolymer (EO20PO70EO20; P123) used as a structure-directing agent. Direct HRSEM observat

The effect of a high magnetic field on the orientation of mesochannels in continuous mesoporous silica films is demonstrated; the orientation of mesochannels in the film can be induced parallel to the magnetic field, though the effect is not complete.

Silica-based materials have found many applications in various fields. Alkoxysilanes have been most widely used as precursors. Fine structural control of silica-based materials has become increasingly important for tuning their properties and for developing new functions. In this perspective, utilization of alkoxysilyl groups has been reviewed from the viewpoint of designing siloxane-based nanomaterials. Alkoxy groups have generally been used only as eliminating groups in the sol–gel processing;