Titanium Dioxide Nanomaterials: Synthesis, Properties, Modifications, and Applications

Core/Shell Nanoparticles: Classes, Properties, Synthesis Mechanisms, Characterization, and Applications

A review on highly ordered, vertically oriented TiO2 nanotube arrays: Fabrication, material properties, and solar energy applications

Water gelation by small organic molecules.

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Chemical strategies to design textured materials: from microporous and mesoporous oxides to nanonetworks and hierarchical structures.

The helical ribbon and double-layered nanotubular structures of the titanium dioxide were created by sol−gel polymerization of Ti(OiPr)4] using 1 as a template in 1-butanol. All TiO2 nanotubes consist of two layers, 8−9 nm of nanospace between layers. In addition, the helicity of the helical ribbon titanium dioxide showed a right-handed motif.

Creation of Novel Helical Ribbon and Double-Layered Nanotube TiO2 Structures Using an Organogel Template

Creation of Both Right-Handed and Left-Handed Silica Structures by Sol−Gel Transcription of Organogel Fibers Comprised of Chiral Diaminocyclohexane Derivatives

A new sugar-based gelator 1 was synthesized, and its gelation ability was evaluated in organic solvents and water. Very surprisingly, 1 was found to gelate organic solvents as well as water, indicating that 1 can act as an amphiphilic gelator. We characterized on superstructures of an aqueous gel from 1 using SEM, TEM, NMR, IR, and XRD. The aqueous gel 1 formed a three-dimensional network with 20−500 nm diameter puckered fibrils. In addition, the chiral aggregate was found to be largely twisted helical ribbons with ca. 85 nm width, ca. 315 nm pitch, and up to several micrometer length, whose helicity was exclusively left-handed. XRD diagrams indicate that an aqueous gel 1 maintains a bilayered structure with 2.90 nm long-range spacing. This gives the first example of the formation of well ordered bilayer-based aqueous gel. The XRD, FT-NMR, and FT-IR results suggested that the aqueous gel 1 is stabilized by a combination of the hydrogen bonding, π−π interactions, and hydrophobic forces.

Self-Assembly of a Sugar-Based Gelator in Water: Its Remarkable Diversity in Gelation Ability and Aggregate Structure

An aldopyranoside-based gelators (dodecanoyl-p-aminophenyl-beta-D-aldopyranoside)s and [1,12-dodecanedicarboxylic-bis(p-aminophenyl-beta-D-aldopyranoside)]s 1-4 were synthesized, and their gelation ability was evaluated in organic solvents and water. Simple aldopyranoside amphiphiles 1 and 2 were found to gelate organic solvents as well as water in the presence of a small amount of alcoholic solvents. More interestingly, not only extremely dilute aqueous solutions (0.05 wt%) of the bolaamphiphiles 3 and 4, but solutions of 3 and 4 in several organic solvents could be gelatinized. These results indicate that 1-4 can act as versatile amphiphilic gelators. We characterized the superstructures of the aqueous gels and organogels prepared from 1-4 using SEM, TEM, NMR and IR spectroscopy, and XRD. The aqueous gels 1 and 2 formed a three-dimensional network of puckered fibrils diameters in the range 20-200 nm, whereas the aqueous gels 3 and 4 produced filmlike lamellar structures with 50-100 nm thickness at extremely low concentrations (0.05 wt%). Powder XRD experiments indicate that the aqueous gels 1 and 2 maintain an interdigitated bilayer structure with a 2.90 nm period with the alkyl chain tilted, while the organogels 1 and 2 take a loosely interdigitated bilayer structure with a 3.48 nm period. On the other hand, the aqueous- and the organogels 3 and 4 have 3.58 nm spacing, which corresponds to a monolayered structure. The XRD, 1H NMR and FT-IR results suggest that 1-4 are stabilized by a combination of the hydrogen-bonding, pi-pi interactions and hydrophobic forces.

Spectral Characterization of Self‐Assemblies of Aldopyranoside Amphiphilic Gelators: What is the Essential Structural Difference Between Simple Amphiphiles and Bolaamphiphiles?

Four long-chain phenyl glucoside amphiphiles possessing a saturated or unsaturated long alkyl chain group as the self-assembling unit of a highly organized molecular architecture were synthesized. Their self-assembling properties were investigated by EF-TEM, SEM, CD, FT-IR, and XRD. Compound 2 possessing one double bond in the lipophilic portion showed twisted helical fibers, which formed a bilayered structure with a 3.59 nm period, while compound 3 showed the helical ribbons and left-handed nanotubular structures with 150-200 nm inner diameters and ca. 20 nm of wall. Very interestingly, compound 4 possessing three double bonds showed a nanotubular structure with ca. 70 nm of inner diameter through a helical ribbon, which formed a loose bilayered structure with 4.62 nm. These results indicate that self-assembling properties strongly depend on the number of cis double bonds.

Jong Hwa Jung

Papers

Creation of Novel Helical Ribbon and Double-Layered Nanotube TiO2 Structures Using an Organogel Template

Creation of Both Right-Handed and Left-Handed Silica Structures by Sol−Gel Transcription of Organogel Fibers Comprised of Chiral Diaminocyclohexane Derivatives

Self-Assembly of a Sugar-Based Gelator in Water: Its Remarkable Diversity in Gelation Ability and Aggregate Structure

Spectral Characterization of Self‐Assemblies of Aldopyranoside Amphiphilic Gelators: What is the Essential Structural Difference Between Simple Amphiphiles and Bolaamphiphiles?

Self-assembling structures of long-chain phenyl glucoside influenced by the introduction of double bonds.