Abstract: A method is disclosed of assembling building blocks into supraparticles. The method includes applying a first solvent on a template of patterned recessed regions to wet surfaces of the recessed regions; applying a second solvent on the template of patterned recessed regions, the building blocks suspended in the second solvent; wherein the first solvent and the second solvent are partially miscible, resulting in negligible interfacial surface tension between the first and second solvents; and wherein droplets of the second solvent diffuse droplets of the first solvent in the recessed regions, thereby assembling the building blocks into the supraparticles in the recessed regions.

Abstract: A method of forming magnetic/plasmonic hybrid structures is disclosed. The method includes synthesizing colloidal magnetic nanoparticles; modifying the magnetic nanoparticles in a solution of a polymeric ligand; binding metal seed nanoparticles to the surface of the magnetic nanoparticles; and performing a seed-mediated growth on the metal seed nanoparticles by reducing a metal salt in solution to form the magnetic/plasmonic hybrid structures.

Abstract: Photonic pigments are disclosed, which include a plurality of magnetic nanorods assembled into tetragonal colloidal crystals.

Abstract: A system and method are disclosed of electrostatic alignment and surface assembly of photonic crystals for dynamic color exhibition. The method includes aligning a plurality of photonic crystal chains in a solution to exhibit color.

Abstract: A system and method are disclosed of electrostatic alignment and surface assembly of photonic crystals for dynamic color exhibition. The method includes: dispersing a plurality of photonic crystal chains into a solution; placing the solution of the plurality of photonic crystal chains in a container; and assembling and aligning the plurality of photonic crystal chains in the solution by a local charge build up on a surface of the container to exhibit color.

Abstract: A method is disclosed of forming magnetically tunable photonic crystals comprising: synthesizing one or more precursory nanoparticles with anisotropic shapes; coating the one or more anisotropic precursory nanoparticles with silica to form composite structures; converting the one or more anisotropic precursory nanoparticles into magnetic nanomaterials through chemical reactions; and assembling the anisotropic magnetic nanoparticles into photonic crystals in a solvent.

Abstract: A method and system are disclosed for generating a dynamic and responsive color media. The method includes encapsulating nanomaterials within a capsule to form encapsulated photonic crystals; and dispersing the encapsulated photonic crystals within a film or substrate, wherein the encapsulated nanomaterials retain a liquid dispersion state and can move freely within the capsule and the capsules containing photonic crystals remain stationary within the film or substrate.

Abstract: A system and method are disclosed of electrostatic alignment and surface assembly of photonic crystals for dynamic color exhibition. The method includes: dispersing a plurality of photonic crystal chains into a solution; placing the solution of the plurality of photonic crystal chains in a container; and assembling and aligning the plurality of photonic crystal chains in the solution by a local charge build up on a surface of the container to exhibit color.

Abstract: Alloyed Ag/Au nanospheres with high compositional homogeneity ensured by annealing at elevated temperatures show large extinction cross-sections, extremely narrow band-widths and remarkable stability in harsh chemical environments. A critical temperature has been found to be around 930° C., below which the resulting alloy nanospheres, although significantly more stable than pure silver nanoparticles, can still gradually decay upon extended exposure to harsh etchant. The nanospheres annealed above the critical temperature show homogeneous distribution of Ag and Au elements, minimal crystallographic defects, absence of structural and compositional interfaces, which account for the extremely narrow bandwidths of the surface plasmon resonance, and may render many plasmonic applications with high performance and long lifetime, especially for those involving corrosive species.

Abstract: The production of photocatalytic color switching of redox imaging nanomaterials for rewritable media is disclosed. The new color switching system is based on photocatalytic redox reaction enabling reversible and considerably fast color switching in response to light irradiation. In accordance with an exemplary embodiment, the color switching system can include a photocatalyst and an imaging media. With the assistance of photocatalyst, UV light irradiation can rapidly reduce the redox imaging nanomaterials accompany with obvious color changing, while the resulting reduced system can be switched back to original color state through visible light irradiation or heating in air condition. The excellent performance of the new color switching system promises their potential use as an attractive rewritable media to meet increasing needs for sustainability and environmental protection.

Abstract: In various embodiments magnetically actuated liquid crystals are provided as well as method of manufacturing such, methods of using the liquid crystals and devices incorporating the liquid crystals. In one non-limiting embodiment the liquid crystals comprise Fe3O4 nanorods where the nanorods are coated with a silica coating.

Abstract: In various embodiments magnetically actuated liquid crystals are provided as well as method of manufacturing such, methods of using the liquid crystals and devices incorporating the liquid crystals. In one non-limiting embodiment the liquid crystals comprise Fe3O4 nanorods where the nanorods are coated with a silica coating.

Abstract: Provided is a method of forming a microsphere having a structural color, which includes providing a composition for generating a structural color including a curable material and magnetic nanoparticles dispersed in the curable material, forming an emulsion by adding the composition for generating a structural color to an immiscible solvent, arranging the magnetic nanoparticles located in the emulsion droplet of the curable material in a one-dimensional chain structure by applying a magnetic field to the emulsion, and fixing the chain structure by curing the emulsion droplet.

Abstract: Monodisperse colloidal nanocrystal clusters of magnetite (Fe3O4) with tunable sizes from about thirty to about three hundred nanometers have been synthesized using a high-temperature hydrolysis process. The colloidal nanocrystal clusters are capped with polyelectrolytes, and highly water soluble. Each cluster is composed of many single magnetite crystallites, thus retaining the superparamagnetic behavior at room temperature. The combination of superparamagnetic property, high magnetization, and high water dispersibility makes the colloidal nanocrystal clusters ideal candidates for various important biomedical applications such as drug delivery and bioseparation. The present invention is further directed to methods for forming colloidal photonic crystals from both aqueous and nonaqueous solutions of the superparamagnetic colloidal nanocrystal clusters with an external magnetic field applied thereto.

Abstract: The development of a stress-responsive colorimetric film that can memorize the stress it has experienced is disclosed. The system can use the plasmonic shift associated with the disassembly of one-dimensional plasmonic nanoparticle chains driven by the plastic deformation of the surrounding polymer matrix. By modifying the plasticity of the polymer, the plasmonic shift and colorimetric change can respond to a large range of stresses. The pressure indicating film can be used to capture and record the pressure distribution and magnitude between two contacting or impacting surfaces by outputting color information.

Abstract: The development of a stress-responsive colorimetric film that can memorize the stress it has experienced is disclosed. The system can use the plasmonic shift associated with the disassembly of one-dimensional plasmonic nanoparticle chains driven by the plastic deformation of the surrounding polymer matrix. By modifying the plasticity of the polymer, the plasmonic shift and colorimetric change can respond to a large range of stresses. The pressure indicating film can be used to capture and record the pressure distribution and magnitude between two contacting or impacting surfaces by outputting color information.

Abstract: A method is disclosed of forming magnetically tunable photonic crystals comprising: synthesizing one or more precursory nanoparticles with anisotropic shapes; coating the one or more anisotropic precursory nanoparticles with silica to form composite structures; converting the one or more anisotropic precursory nanoparticles into magnetic nanomaterials through chemical reactions; and assembling the anisotropic magnetic nanoparticles into photonic crystals in a solvent.

Abstract: A method of preparing a metal nanorod. The method includes seeding a metal nanoparticle within the lumen of a nanotube, and growing a metal nanorod from the seeded metal nanoparticle to form a metal nanorod-nanotube composite. In some cases, the nanotube includes metal binding ligands attached to the inner surface. Growing of the metal nanorod includes incubating the seeded nanotube in a solution that includes: a metal source for the metal in the metal nanorod, the metal source including an ion of the metal; a coordinating ligand that forms a stable complex with the metal ion; a reducing agent for reducing the metal ion, and a capping agent that stabilizes atomic monomers of the metal. Compositions derived from the method are also provided.

Abstract: A method of assembling superparamagnetic colloids into ordered structures with magnetically tunable photonic properties in nonpolar solvents by establishing long-range electrostatic repulsive forces using charge control agents. Reverse micelles resulted from the introduction of charge control agents such as AOT molecules can enhance the charge separation on the surfaces of n-octadecyltrimethoxysilane modified Fe3O4@SiO2 particles. The significantly improved long-range electrostatic repulsion can counterbalance the magnetically induced attraction and therefore allow ordering of superparamagnetic colloids in nonpolar solvents. This system possesses fast and fully reversible optical response to the external magnetic fields, long-term stability in performance, and good diffraction intensity.