Layered double hydroxides (LDHs), shown as the general formula of [M2+1−xM3+x(OH)2]x+(An−)x/n∙yH2... more Layered double hydroxides (LDHs), shown as the general formula of [M2+1−xM3+x(OH)2]x+(An−)x/n∙yH2O, are useful for various applications such as anion exchangers/adsorbents, catalysts and catalysts’ supports, and drug/gene carriers due to their structural, compositional and morphological characteristics and their variation. The x value (M3+/(M2+ + M3+) ratio) in layered double hydroxides (LDHs), corresponding to the layer charge density, is one of the important parameters for controlling the properties of LDHs. The x values in commonly available LDHs are limited (0.2 < x < 0.3). In order to obtain LDHs with x < 0.2, Mg2+ Ga3+–LDHs with interlayer iodide were examined. The linear correlation between lattice parameter a and x value in the products with x of 0.06–0.24 was seen, suggesting the successful substitution of Mg2+ in the brucite-like sheet with Ga3+. Carbonate and dodecyl sulfate types MgGa–LDH were prepared by ion exchange with carbonate anion and reconstruction in a...
Electronic Supplementary Information Contents 1. The reversible change in the XRD pattern of the ... more Electronic Supplementary Information Contents 1. The reversible change in the XRD pattern of the AZ +-montmorillonite-phenol upon UV and visible light irradiation (Figure S1). 2. The change in the XRD pattern of the AZ +-montmorillonite-phenol with UV irradiated time to 30 min (Figure S2).
The adsorption of 2,4-dichlorophenol onto the 1,1A-dimethyl-4,4A-bipyridinium-saponite, a smectit... more The adsorption of 2,4-dichlorophenol onto the 1,1A-dimethyl-4,4A-bipyridinium-saponite, a smectite group of clay minerals, from dilute aqueous solution occurred effectively through charge-transfer interactions and such interactions resulted in the change in the color of the 1,1A-dimethyl-4,4Abipyridinium-saponite.
Iron-containing hectorite-like layered silicate was synthesized by the reaction of LiF, Mg(OH) 2 ... more Iron-containing hectorite-like layered silicate was synthesized by the reaction of LiF, Mg(OH) 2 , colloidal silica, and FeCl 3 in aqueous suspension at 100°C for 2 days. From X-ray diffraction and infrared spectroscopic analysis, the formation of hectorite-like layered silicate was shown. Dimethyldioctadecylammonium and 1,1¤-dimethyl-4,4¤bipyridinium (methyl viologen) ions were intercalated by cation-exchange reactions into the interlayer space of the iron-containing silicate. The intercalated amounts of both cationic species were larger compared to iron-free layered silicate, showing increase in the layer charge density of the silicate by the incorporation of iron(III). The increase in the layer charge was thought to be derived from isomorphous substitution of silicon(IV) by iron(III) in the silicate layer. The structural iron(III) was reduced to iron(II) by reaction with sodium dithionite, which was shown by a color-change (yellow to green) and the increase in the intercalated amounts of dimethyldioctadecylammonium and 1,1¤-dimethyl-4,4¤bipyridinium ions.
The effect of the molecular structure of a cationic azo dye on the photoinduced intercalation of ... more The effect of the molecular structure of a cationic azo dye on the photoinduced intercalation of phenol into the azo dye-montmorillonites was reported. Two types of cationic azo dyes were used; one has (2-hydroxyethyl)dimethylammonium group (AZ(OH)+), and the other has trimethylammonium group (AZ(CH3)+). Phenol was intercalated into both cation exchanged azo dye-montmorillonites (Kunipia F) by mechanical mixing without solvent. By
Crystallization of well-defined anatase nanoparticles (5 nm) in the mesopore (6 nm) of SBA-15 ove... more Crystallization of well-defined anatase nanoparticles (5 nm) in the mesopore (6 nm) of SBA-15 over 400 °C, results the high photocatalytic activity for decomposition of acetic acid compared with other commercial titanium dioxides.
Well-defined belt-shaped particles of octacalcium phosphate were prepared by mixing aqueous solut... more Well-defined belt-shaped particles of octacalcium phosphate were prepared by mixing aqueous solutions of calcium acetate and that of sodium phosphate monobasic with the aid of a micro-flow reactor. Higher crystallinity and narrower particle size distribution were achieved by the micro-flow reactor if compared with the results of the batch reaction using the same solutions. The width of the belt was controlled by the mixing temperature (0.8 and 2.3 μm for the preparation at 50 and 70 °C, respectively). Post mixing aging at 50 °C, resulted in the directional growth of belt-shaped particles to obtain particles with the length of 17 μm (aspect ratio of 53). XRD and TEM analysis indicated that the micro-flow reactor could separate nucleation and growth allowing preferential growth along the a-direction.
The adsorption of merocyanine onto mesoporous silicas with varied pore sizes (5.5, 9.4 and 2.2 nm... more The adsorption of merocyanine onto mesoporous silicas with varied pore sizes (5.5, 9.4 and 2.2 nm) from toluene solution of 1,3,3-trimethylindolino-6'-nitrobenzopyrylospiran under UV irradiation was investigated quantitatively. The photoinduced adsorption...
Montmorillonite-acrylamide intercalation compounds were prepared by treating sodium montmorilloni... more Montmorillonite-acrylamide intercalation compounds were prepared by treating sodium montmorillonite with acrylamide aqueous solutions, the concentrations of which were varied from 4% to 20%. The basal spacings of the compounds prepared from 4% and 20% acrylamide aqueous solutions were ca. 15 A and 20 A, respectively. These values suggested that acrylamide was intercalated as monomolecular and bimolecular arrangements in the interlayer space of montmorillonite with the molecular plane perpendicular to the silicate sheet. After the removal of excess acrylamide by washing with nonpolar organic solvents, the intercalated acrylamide was polymerized to form montmorillonite-polyacrylamide intercalation compounds. These compounds absorbed more water than raw sodium montmorillonite.
Abstract Novel hybrids composed of mixed metal sulfides (manganese sulfide and zinc sulfide (MnS/... more Abstract Novel hybrids composed of mixed metal sulfides (manganese sulfide and zinc sulfide (MnS/ZnS) or cadmium sulfide (MnS/CdS), as well as zinc sulfide and cadmium sulfide (ZnS/CdS)) with montmorillonite were synthesized by solid–solid reactions between the ion exchanged montmorillonite and sodium sulfide. The products were characterized by powder X-ray diffraction, transmission electron microscopy, as well as Raman, UV–visible and photoluminescence spectroscopies. The Raman spectra indicated the presence of manganese sulfide, zinc sulfide, and/or cadmium sulfide in the products. The absorption onsets observed at 318–366 nm for MnS/ZnS@montmorillonite, at 330–521 nm for MnS/CdS@montmorillonite, and at 360–480 nm for ZnS/CdS@montmorillonite indicated the formation of two metal sulfides in the interlayer spaces. In comparison with those of bulk MnS (340 nm), ZnS (360 nm) and CdS (525 nm), the absorption onsets owing to both metal sulfides were blue shifted probably due to quantum confinement effect, suggesting that the products are composed of nanometer sized sulfide particles. The photoluminescence bands owing to manganese sulfide (416 and 435 nm), zinc sulfide (413 and 440 nm), and cadmium sulfide (451 and 469 nm) were also seen. The emission intensity of MnS/ZnS@montmorillonite was stronger than that of MnS/CdS@montmorillonite, probably due to the higher band gap energy of MnS/ZnS system that resulted in the increase of recombination of excitons.
A novel synthetic route for the preparation of the porous silica by a supramolecular templating m... more A novel synthetic route for the preparation of the porous silica by a supramolecular templating mechanism is reported. By depositing the precursor solution containing tetramethoxysilane and hexadecyltrimethylammonium chloride on glass plates at an elevated temperature (60 • C), mesostructured silica-hexadecyltrimethylammonium chloride composites with the size of a few mm to a cm have been prepared. The composition of the resulting products can be controlled by simply changing the composition of the starting mixtures. By the calcination of the as synthesized mesostructured materials, porous silica with large surface area was obtained. Due to the ease of operation, the present method is a simple way to prepare porous silica alternative to the procedures reported for the preparation of mesoporous silicas (MCM-41 and FSM-16).
The surface modification of a layered alkali silicate, octosilicate (Na(2)Si(8)O(17)·nH2O), with ... more The surface modification of a layered alkali silicate, octosilicate (Na(2)Si(8)O(17)·nH2O), with a sulfonic acid group was conducted. The sulfonic acid group was attached to the silicate layer by the reaction of octosilicate with phenethyl(dichloro)methylsilane and the subsequent sulfonation of the attached phenethyl groups with chlorosulfonic acid. The modified octosilicate is a solid acid as indicated by the intercalation of dodecylamine. A systematic expansion of the interlayer space was observed by the ion exchange with a series of alkyltrimethylammonium ions to show the variation of the layer charge density.
Anionically charged colloidal particles (β-iron oxyhydroxide and smectite clay) were successfully... more Anionically charged colloidal particles (β-iron oxyhydroxide and smectite clay) were successfully removed from the suspension by the interactions with micrometer-sized hydrotalcite. The efficiency of the removal was evaluated by an examination of concentration-dependent experiments.
Thin layers (with the thickness of several tens of nanometers) of silica-surfactant hybrids were ... more Thin layers (with the thickness of several tens of nanometers) of silica-surfactant hybrids were deposited on flat glass substrate from aqueous methanol solution of tetraethoxysilane, phenyltriethoxysilane, alkyltrimethylammonium chloride, and ammonia by the reaction at room temperature. Multilayered films were deposited on flat substrates by repeating the film preparation procedure. Due to the reproducible syntheses, the films are possible candidates as scaffold of sensor and photonic coatings. A hexagonal platy core-shell particle with a hydrotalcite core and organosilica shell was also synthesized by the reaction of hydrotalcite with aqueous methanol solution containing tetraethoxysilane, hexadecyltrimethylammonium chloride, and ammonia. A hollow hexagonal platy particle was obtained by removing the hydrotalcite from the core-shell particle by acidic leaching. The organosilica-coated particles may affect the anion exchange selectivity of hydrotalcite, and the organosilica hollow particle is possible candidate as a new class of carried due to the unique platy particle shape.
Layered double hydroxides (LDHs), shown as the general formula of [M2+1−xM3+x(OH)2]x+(An−)x/n∙yH2... more Layered double hydroxides (LDHs), shown as the general formula of [M2+1−xM3+x(OH)2]x+(An−)x/n∙yH2O, are useful for various applications such as anion exchangers/adsorbents, catalysts and catalysts’ supports, and drug/gene carriers due to their structural, compositional and morphological characteristics and their variation. The x value (M3+/(M2+ + M3+) ratio) in layered double hydroxides (LDHs), corresponding to the layer charge density, is one of the important parameters for controlling the properties of LDHs. The x values in commonly available LDHs are limited (0.2 < x < 0.3). In order to obtain LDHs with x < 0.2, Mg2+ Ga3+–LDHs with interlayer iodide were examined. The linear correlation between lattice parameter a and x value in the products with x of 0.06–0.24 was seen, suggesting the successful substitution of Mg2+ in the brucite-like sheet with Ga3+. Carbonate and dodecyl sulfate types MgGa–LDH were prepared by ion exchange with carbonate anion and reconstruction in a...
Electronic Supplementary Information Contents 1. The reversible change in the XRD pattern of the ... more Electronic Supplementary Information Contents 1. The reversible change in the XRD pattern of the AZ +-montmorillonite-phenol upon UV and visible light irradiation (Figure S1). 2. The change in the XRD pattern of the AZ +-montmorillonite-phenol with UV irradiated time to 30 min (Figure S2).
The adsorption of 2,4-dichlorophenol onto the 1,1A-dimethyl-4,4A-bipyridinium-saponite, a smectit... more The adsorption of 2,4-dichlorophenol onto the 1,1A-dimethyl-4,4A-bipyridinium-saponite, a smectite group of clay minerals, from dilute aqueous solution occurred effectively through charge-transfer interactions and such interactions resulted in the change in the color of the 1,1A-dimethyl-4,4Abipyridinium-saponite.
Iron-containing hectorite-like layered silicate was synthesized by the reaction of LiF, Mg(OH) 2 ... more Iron-containing hectorite-like layered silicate was synthesized by the reaction of LiF, Mg(OH) 2 , colloidal silica, and FeCl 3 in aqueous suspension at 100°C for 2 days. From X-ray diffraction and infrared spectroscopic analysis, the formation of hectorite-like layered silicate was shown. Dimethyldioctadecylammonium and 1,1¤-dimethyl-4,4¤bipyridinium (methyl viologen) ions were intercalated by cation-exchange reactions into the interlayer space of the iron-containing silicate. The intercalated amounts of both cationic species were larger compared to iron-free layered silicate, showing increase in the layer charge density of the silicate by the incorporation of iron(III). The increase in the layer charge was thought to be derived from isomorphous substitution of silicon(IV) by iron(III) in the silicate layer. The structural iron(III) was reduced to iron(II) by reaction with sodium dithionite, which was shown by a color-change (yellow to green) and the increase in the intercalated amounts of dimethyldioctadecylammonium and 1,1¤-dimethyl-4,4¤bipyridinium ions.
The effect of the molecular structure of a cationic azo dye on the photoinduced intercalation of ... more The effect of the molecular structure of a cationic azo dye on the photoinduced intercalation of phenol into the azo dye-montmorillonites was reported. Two types of cationic azo dyes were used; one has (2-hydroxyethyl)dimethylammonium group (AZ(OH)+), and the other has trimethylammonium group (AZ(CH3)+). Phenol was intercalated into both cation exchanged azo dye-montmorillonites (Kunipia F) by mechanical mixing without solvent. By
Crystallization of well-defined anatase nanoparticles (5 nm) in the mesopore (6 nm) of SBA-15 ove... more Crystallization of well-defined anatase nanoparticles (5 nm) in the mesopore (6 nm) of SBA-15 over 400 °C, results the high photocatalytic activity for decomposition of acetic acid compared with other commercial titanium dioxides.
Well-defined belt-shaped particles of octacalcium phosphate were prepared by mixing aqueous solut... more Well-defined belt-shaped particles of octacalcium phosphate were prepared by mixing aqueous solutions of calcium acetate and that of sodium phosphate monobasic with the aid of a micro-flow reactor. Higher crystallinity and narrower particle size distribution were achieved by the micro-flow reactor if compared with the results of the batch reaction using the same solutions. The width of the belt was controlled by the mixing temperature (0.8 and 2.3 μm for the preparation at 50 and 70 °C, respectively). Post mixing aging at 50 °C, resulted in the directional growth of belt-shaped particles to obtain particles with the length of 17 μm (aspect ratio of 53). XRD and TEM analysis indicated that the micro-flow reactor could separate nucleation and growth allowing preferential growth along the a-direction.
The adsorption of merocyanine onto mesoporous silicas with varied pore sizes (5.5, 9.4 and 2.2 nm... more The adsorption of merocyanine onto mesoporous silicas with varied pore sizes (5.5, 9.4 and 2.2 nm) from toluene solution of 1,3,3-trimethylindolino-6'-nitrobenzopyrylospiran under UV irradiation was investigated quantitatively. The photoinduced adsorption...
Montmorillonite-acrylamide intercalation compounds were prepared by treating sodium montmorilloni... more Montmorillonite-acrylamide intercalation compounds were prepared by treating sodium montmorillonite with acrylamide aqueous solutions, the concentrations of which were varied from 4% to 20%. The basal spacings of the compounds prepared from 4% and 20% acrylamide aqueous solutions were ca. 15 A and 20 A, respectively. These values suggested that acrylamide was intercalated as monomolecular and bimolecular arrangements in the interlayer space of montmorillonite with the molecular plane perpendicular to the silicate sheet. After the removal of excess acrylamide by washing with nonpolar organic solvents, the intercalated acrylamide was polymerized to form montmorillonite-polyacrylamide intercalation compounds. These compounds absorbed more water than raw sodium montmorillonite.
Abstract Novel hybrids composed of mixed metal sulfides (manganese sulfide and zinc sulfide (MnS/... more Abstract Novel hybrids composed of mixed metal sulfides (manganese sulfide and zinc sulfide (MnS/ZnS) or cadmium sulfide (MnS/CdS), as well as zinc sulfide and cadmium sulfide (ZnS/CdS)) with montmorillonite were synthesized by solid–solid reactions between the ion exchanged montmorillonite and sodium sulfide. The products were characterized by powder X-ray diffraction, transmission electron microscopy, as well as Raman, UV–visible and photoluminescence spectroscopies. The Raman spectra indicated the presence of manganese sulfide, zinc sulfide, and/or cadmium sulfide in the products. The absorption onsets observed at 318–366 nm for MnS/ZnS@montmorillonite, at 330–521 nm for MnS/CdS@montmorillonite, and at 360–480 nm for ZnS/CdS@montmorillonite indicated the formation of two metal sulfides in the interlayer spaces. In comparison with those of bulk MnS (340 nm), ZnS (360 nm) and CdS (525 nm), the absorption onsets owing to both metal sulfides were blue shifted probably due to quantum confinement effect, suggesting that the products are composed of nanometer sized sulfide particles. The photoluminescence bands owing to manganese sulfide (416 and 435 nm), zinc sulfide (413 and 440 nm), and cadmium sulfide (451 and 469 nm) were also seen. The emission intensity of MnS/ZnS@montmorillonite was stronger than that of MnS/CdS@montmorillonite, probably due to the higher band gap energy of MnS/ZnS system that resulted in the increase of recombination of excitons.
A novel synthetic route for the preparation of the porous silica by a supramolecular templating m... more A novel synthetic route for the preparation of the porous silica by a supramolecular templating mechanism is reported. By depositing the precursor solution containing tetramethoxysilane and hexadecyltrimethylammonium chloride on glass plates at an elevated temperature (60 • C), mesostructured silica-hexadecyltrimethylammonium chloride composites with the size of a few mm to a cm have been prepared. The composition of the resulting products can be controlled by simply changing the composition of the starting mixtures. By the calcination of the as synthesized mesostructured materials, porous silica with large surface area was obtained. Due to the ease of operation, the present method is a simple way to prepare porous silica alternative to the procedures reported for the preparation of mesoporous silicas (MCM-41 and FSM-16).
The surface modification of a layered alkali silicate, octosilicate (Na(2)Si(8)O(17)·nH2O), with ... more The surface modification of a layered alkali silicate, octosilicate (Na(2)Si(8)O(17)·nH2O), with a sulfonic acid group was conducted. The sulfonic acid group was attached to the silicate layer by the reaction of octosilicate with phenethyl(dichloro)methylsilane and the subsequent sulfonation of the attached phenethyl groups with chlorosulfonic acid. The modified octosilicate is a solid acid as indicated by the intercalation of dodecylamine. A systematic expansion of the interlayer space was observed by the ion exchange with a series of alkyltrimethylammonium ions to show the variation of the layer charge density.
Anionically charged colloidal particles (β-iron oxyhydroxide and smectite clay) were successfully... more Anionically charged colloidal particles (β-iron oxyhydroxide and smectite clay) were successfully removed from the suspension by the interactions with micrometer-sized hydrotalcite. The efficiency of the removal was evaluated by an examination of concentration-dependent experiments.
Thin layers (with the thickness of several tens of nanometers) of silica-surfactant hybrids were ... more Thin layers (with the thickness of several tens of nanometers) of silica-surfactant hybrids were deposited on flat glass substrate from aqueous methanol solution of tetraethoxysilane, phenyltriethoxysilane, alkyltrimethylammonium chloride, and ammonia by the reaction at room temperature. Multilayered films were deposited on flat substrates by repeating the film preparation procedure. Due to the reproducible syntheses, the films are possible candidates as scaffold of sensor and photonic coatings. A hexagonal platy core-shell particle with a hydrotalcite core and organosilica shell was also synthesized by the reaction of hydrotalcite with aqueous methanol solution containing tetraethoxysilane, hexadecyltrimethylammonium chloride, and ammonia. A hollow hexagonal platy particle was obtained by removing the hydrotalcite from the core-shell particle by acidic leaching. The organosilica-coated particles may affect the anion exchange selectivity of hydrotalcite, and the organosilica hollow particle is possible candidate as a new class of carried due to the unique platy particle shape.
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