Massive hydration-driven swelling of layered perovskite niobate crystals in aqueous solutions of organo-ammonium bases.

Osmotic swelling behaviors in layered perovskite niobate were examined in aqueous solutions containing three types of amine-related agents including quaternary ammonium hydroxides and tertiary aminoethanol. Platelet microcrystals of a protonated layered perovskite niobate, HCaNbO·1.5HO, were found to show enormous swelling in the aqueous solutions, which was clearly recognized by the noticeable expansion of the sample volume over 100-fold.

Flexible Lithium-Ion Fiber Battery by the Regular Stacking of Two-Dimensional Titanium Oxide Nanosheets Hybridized with Reduced Graphene Oxide.

Increasing interest has recently been devoted to developing small, rapid, and portable electronic devices; thus, it is becoming critically important to provide matching light and flexible energy-storage systems to power them. To this end, compared with the inevitable drawbacks of being bulky, heavy, and rigid for traditional planar sandwiched structures, linear fiber-shaped lithium-ion batteries (LIB) have become increasingly important owing to their combined superiorities of miniaturization, adaptability, and weavability, the progress of which being heavily dependent on the development of new fiber-shaped electrodes. Here, we report a novel fiber battery electrode based on the most widely used LIB material, titanium oxide, which is processed into two-dimensional nanosheets and assembled into a macroscopic fiber by a scalable wet-spinning process.

Accordion-like swelling of layered perovskite crystals via massive permeation of aqueous solutions into 2D oxide galleries.

Platelet crystals of a layered perovskite showed massive accordion-like swelling in a tetrabutylammonium hydroxide solution. The permeation of the solution induced the huge expansion of the interlayer spacing as well as the crystal thickness up to 50-fold, leading to a very high water content of >90 wt%.

Macroscopic and Strong Ribbons of Functionality-Rich Metal Oxides from Highly Ordered Assembly of Unilamellar Sheets.

The strong interest in macroscopic graphene and/or carbon nanotube (CNT) fiber has highlighted that anisotropic nanostructured materials are ideal components for fabricating fiber assemblies. Prospectively, employing two-dimensional (2D) crystals or nanosheets of functionality-rich transition metal oxides would notably enrich the general knowledge for desirable fiber constructions and more importantly would greatly broaden the scope of functionalities. However, the fibers obtained up to now have been limited to carbon-related materials, while those made of 2D crystals of metal oxides have not been achieved, probably due to the intrinsically low mechanical stiffness of a molecular sheet of metal oxides, which is only few hundredths of that for graphene.