A nanocomposite includes a plurality of nanoparticles, where each nanoparticle of the plurality of nanoparticles includes a TiO.sub.2 nanoparticle core characterized by a diameter between about 1 nm and about 20 nm and a surface .OH density below about 6.OH/nm.sup.2, and a nanoparticle shell conformally formed on surfaces of the TiO.sub.2 nanoparticle core. The nanoparticle shell is continuous and is thinner than about 2 nm. The nanoparticle shell includes a transparent material with a refractive index greater than about 1.7 for visible light. A valence band of the nanoparticle shell is more than about 0.1 eV lower than a valence band of the TiO.sub.2 nanoparticle core. A conduction band of the nanoparticle shell is more than about 0.5 eV higher than a conduction band of the TiO.sub.2 nanoparticle core.

A nanocomposite includes a plurality of nanoparticles, where each nanoparticle of the plurality of nanoparticles includes a TiO.sub.2 nanoparticle core characterized by a diameter between about 1 nm and about 20 nm and a surface .OH density below about 6.OH/nm.sup.2, and a nanoparticle shell conformally formed on surfaces of the TiO.sub.2 nanoparticle core. The nanoparticle shell is continuous and is thinner than about 2 nm. The nanoparticle shell includes a transparent material with a refractive index greater than about 1.7 for visible light. A valence band of the nanoparticle shell is more than about 0.1 eV lower than a valence band of the TiO.sub.2 nanoparticle core. A conduction band of the nanoparticle shell is more than about 0.5 eV higher than a conduction band of the TiO.sub.2 nanoparticle core.

In an embodiment, a system includes a three-dimensional (3D) printer, a neutral feedstock, a p-doped feedstock, an n-doped feedstock, and a laser. The 3D printer includes a platen and an enclosure. The platen includes an inert metal. The enclosure includes an inert atmosphere. The neutral feedstock is configured to be deposited onto the platen. The neutral feedstock includes a halogenated solution and a nanoparticle having a negative electron affinity. The p-doped feedstock is configured to be deposited onto the platen. The p-doped feedstock includes a boronated compound introduced to the neutral feedstock. The n-doped feedstock is configured to be deposited onto the platen. The n-doped feedstock includes a phosphorous compound introduced to the neutral feedstock. The laser is configured to induce the nanoparticle to emit solvated electrons into the halogenated solution to form, by reduction, layers of a ceramic comprising a neutral layer, a p-doped layer, and an n-doped layer.

The invention described herein provides a dry graphene powder composition comprising pristine graphene flakes, wherein the pristine graphene flakes are non-covalently functionalised with polymeric amphiphilic molecules and wherein the dry graphene powder composition is capable of forming a stable homogeneous dispersion in aqueous or alcoholic media, in the absence of free dispersants or stabilizers, as well as methods for producing same, and the use thereof in graphene inks, for 2D and 3D printing, for production of flexible circuits, electrodes, electrocatalysts, for fabrication of nanocomposites and for wet-spinning of pristine graphene fibers.

The invention described herein provides a dry graphene powder composition comprising pristine graphene flakes, wherein the pristine graphene flakes are non-covalently functionalised with polymeric amphiphilic molecules and wherein the dry graphene powder composition is capable of forming a stable homogeneous dispersion in aqueous or alcoholic media, in the absence of free dispersants or stabilizers, as well as methods for producing same, and the use thereof in graphene inks, for 2D and 3D printing, for production of flexible circuits, electrodes, electrocatalysts, for fabrication of nanocomposites and for wet-spinning of pristine graphene fibers.

Described herein is a process for preparing a flexible packaging material. The process may comprise: providing a printed first flexible substrate comprising an ink composition on a surface of a first flexible substrate, the ink composition comprising a first thermoplastic resin; depositing a further composition comprising a cross-linker, a white pigment and a second thermoplastic resin onto the printed ink composition such that the thermoplastic resin of the ink composition is cross-linked; and laminating the first flexible substrate with a second flexible substrate such that the ink composition, the further composition and the cross-linker are disposed between the first and second flexible substrates.

The present invention relates to the use of coating compositions, comprising shaped transition metal, especially silver, particles and a binder, wherein the ratio of pigment to binder is preferably such that the resulting coating shows an angle dependent colour change, for the production of security elements and holograms. When the coating compositions of the present invention are used in coating a hologram the obtained products show a an angle dependent colour change (flip/flop effect), different colours in reflection and transmission, an extremely bright OVD image and extremely strong rainbow effect, high purity and contrast.

The present invention relates to the use of coating compositions, comprising shaped transition metal, especially silver, particles and a binder, wherein the ratio of pigment to binder is preferably such that the resulting coating shows an angle dependent colour change, for the production of security elements and holograms. When the coating compositions of the present invention are used in coating a hologram the obtained products show a an angle dependent colour change (flip/flop effect), different colours in reflection and transmission, an extremely bright OVD image and extremely strong rainbow effect, high purity and contrast.

An image forming method includes a step of forming a white image by bringing a solution (A) containing a dissolved metal compound and a solution (B) containing a reactive ion reactive with a metal element of the metal compound into contact with each other on a recording medium to produce a white compound.

An image forming method includes a step of forming a white image by bringing a solution (A) containing a dissolved metal compound and a solution (B) containing a reactive ion reactive with a metal element of the metal compound into contact with each other on a recording medium to produce a white compound.