A radiation-scattering composition, comprising a plurality of colloidal crystals or aggregates of colloidal crystals, each said crystal comprising radiation reflecting particles in a colloidal array and radiation absorbing particles dispersed in the crystals. The composition scatters radiation in a wavelength band in substantially all directions and absorbs radiation.

A method of producing crystalline cellulose from a cellulosic material includes the step of reacting the cellulosic material in an aqueous slurry comprising a transition metal catalyst and a hypohalite solution.

A method of producing crystalline cellulose from a cellulosic material includes the step of reacting the cellulosic material in an aqueous slurry comprising a transition metal catalyst and a hypohalite solution.

In one aspect, organic-inorganic nanoparticle compositions are described herein comprising engineered surfaces which, in some embodiments, reduce non-radiative recombination mechanisms, thereby providing optoelectronic devices with enhanced efficiencies. In some embodiments, a nanoparticle composition comprises a layer of organic-inorganic perovskite nanocrystals, the organic-inorganic perovskite nanocrystals comprising surfaces associated with growth passivation ligands and trap passivation ligands, wherein the growth passivation ligands are larger than the trap passivation ligands and are of size unable to incorporate into octahedral corner sites of the perovskite crystal structure.

A method for producing an array or bed of metallic nanotubes includes formation of nanowires made from sacrificial material on a growth support, deposition of a metal layer on the nanowires so as to form metallic nanotubes concentric with the nanowires, deposition of a polymer binding layer between the nanowires, elimination of the support, the binding layer supporting the metallic nanotubes, and etching of the sacrificial material.

A group 13 nitride crystal having a hexagonal crystal structure and containing at least a nitrogen atom and at least a metal atom selected from a group consisting of B, Al, Ga, In, and Tl. The group 13 nitride crystal includes a first region disposed on an inner side in a cross section intersecting c-axis, a third region disposed on an outermost side in the cross section and having a crystal property different from that of the first region, and a second region disposed at least partially between the first region and the third region in the cross section, the second region being a transition region of a crystal growth and having a crystal property different from that of the first region and that of the third region.

A method of arranging nanocrystals is provided, which includes a first process of putting barium titanate nanocrystals and/or strontium titanate nanocrystals, and a nonpolar solvent into a container, a second process of collecting a supernatant liquid including the barium titanate nanocrystals and/or the strontium titanate nanocrystals from the container, and a third process of immersing a substrate having an uneven structure into the supernatant liquid, and pulling up the substrate so as to coat the surface of the uneven structure with the supernatant liquid by using a capillary phenomenon, and to arrange the nanocrystals on the uneven structure.

A method of producing graphene or other two-dimensional material such as graphene including heating the substrate held within a reaction chamber to a temperature that is within a decomposition range of a precursor, and that allows two-dimensional crystalline material formation from a species released from the decomposed precursor; establishing a steep temperature gradient (preferably >1000° C. per meter) that extends away from the substrate surface towards an inlet for the precursor; and introducing precursor through the relatively cool inlet and across the temperature gradient towards the substrate surface. The steep temperature gradient ensures that the precursor remains substantially cool until it is proximate the substrate surface thus minimizing decomposition or other reaction of the precursor before it is proximate the substrate surface. The separation between the precursor inlet and the substrate is less than 100 mm.

A method of producing graphene or other two-dimensional material such as graphene including heating the substrate held within a reaction chamber to a temperature that is within a decomposition range of a precursor, and that allows two-dimensional crystalline material formation from a species released from the decomposed precursor; establishing a steep temperature gradient (preferably >1000° C. per meter) that extends away from the substrate surface towards an inlet for the precursor; and introducing precursor through the relatively cool inlet and across the temperature gradient towards the substrate surface. The steep temperature gradient ensures that the precursor remains substantially cool until it is proximate the substrate surface thus minimizing decomposition or other reaction of the precursor before it is proximate the substrate surface. The separation between the precursor inlet and the substrate is less than 100 mm.

The invention relates to nano-particles comprising metallic ferromagnetic nanocrystals combined with either amorphous or graphitic carbon in which or on which chemical groups are present that can dissociate in aqueous solutions.

According to the invention there is provided nano-particles comprising metal particles of at least one ferromagnetic metal, which metal particles are at least in part encapsulated by graphitic carbon.

The nano-particles of the invention are prepared by impregnating carbon containing bodies with an aqueous solution of at least one ferromagnetic metal precursor, drying the impregnated bodies, followed by heating the impregnated bodies in an inert and substantially oxygen-free atmosphere, thereby reducing the metal compounds to the corresponding metal or metal alloy.