Apparatuses for manipulating a color displayed by an article of wear comprising iron oxide colloidal nanocrystals arranged within chains are described. The apparatus includes (a) a magnetic field source, wherein a strength of a magnetic field generated by the magnetic field source is tunable to control the color displayed by the article of wear, and (b) an energy source, wherein energy generated by the energy source is applied to at least some of the chains of nanocrystals to soften materials within the article of wear immediately surrounding the chains of nanocrystals to which the energy is applied.

Articles of wear comprises iron oxide colloidal nanocrystals arranged within chains are described. The chains of nanocrystals display a color that is determined by a strength of a magnetic field applied to the chains of nanocrystals, wherein the color is maintained when the magnetic field is removed.

The present invention is in the field of fluids and the like comprising magnetic particles, such as ferromagnetic particles, anti-ferromagnetic particles, ferrimagnetic particles, synthetic magnetic particles, paramagnetic particles, superparamagnetic particles, such as magnetic fluids, a method of stabilizing magnetic particles, use of these fluids and functionalized particles. Such fluids have a large variety of applications, such as sealants, as a sensor, in biomedics, etc.

Systems and methods of manipulating a color displayed by an article of wear comprising iron oxide colloidal nanocrystals arranged within chains are described. Steps may include forming the article of wear from a raw material that include the chains of nanocrystals, applying a magnetic field to the raw material, applying energy to at least some of the chains of nanocrystals to soften materials within the raw material immediately surrounding the chains of nanocrystals to which the energy is applied, adjusting a strength of the magnetic field to control the color displayed by the raw material, removing the energy to allow the materials within the raw material immediately surrounding the chains of nanocrystals to harden and fix a location of the nanocrystals within the chains, and removing the magnetic field.

In one aspect, the present invention relates to a method of making multi-phase particles that include nanoparticulates and matrix, which maintains the nanoparticulates in a dispersed state. A flowing gas dispersion is generated that includes droplets of a precursor medium dispersed in a gas phase. The precursor medium contains liquid vehicle and at least a first precursor to a first material and a second precursor to a second material. The multi-phase particles are formed from the gas dispersion by removing at least a portion of the liquid vehicle from the droplets of precursor medium. The nanoparticulates in the multi-phase particles include the first material and the matrix in the multi-phase particles includes the second material.

The invention concerns thermally insulating materials comprising the aforementioned particles, a process for the preparation of these particles and materials obtained by incorporation of these particles into matrices. The present invention also concerns inorganic spherical and hollow inorganic particles with low apparent density imparting thermal properties to various types of matrices in which they are dispersed.

Methods of manipulating a color displayed by a transfer medium or substrate comprising iron oxide colloidal nanocrystals arranged within chains, wherein each chain of nanocrystals is encapsulated are described. The method includes (a) applying a magnetic field to the transfer medium or substrate to control the color displayed by the transfer medium or substrate; and (b) applying energy to at least some of the chains of nanocrystals at a level that destroys the encapsulation surrounding the chains of nanocrystals to which the energy is applied.

Hybrid microparticle having a polymer core and a shell which surrounds the polymer core at least in sections and which has a silicon dioxide layer; characterized by an RF value, the RF value being defined as the ratio of an external surface area amenable to the adsorption of nitrogen to a surface area which is computable from an arithmetic mean diameter of the hybrid microparticle considered as an ideal sphere, where the shell has a structure selected from: closed and smooth, with the shell having an RF value of between 1 and 1.5; closed and hillocky, with the shell having an RF value of between 1.51 and 3; or open, with the shell having an RF value of greater than 3.01.

In one aspect, the present invention relates to a method of making multi-phase particles that include nanoparticulates and matrix, which maintains the nanoparticulates in a dispersed state. A flowing gas dispersion is generated that includes droplets of a precursor medium dispersed in a gas phase. The precursor medium contains liquid vehicle and at least a first precursor to a first material and a second precursor to a second material. The multi-phase particles are formed from the gas dispersion by removing at least a portion of the liquid vehicle from the droplets of precursor medium. The nanoparticulates in the multi-phase particles include the first material and the matrix in the multi-phase particles includes the second material.

Provided is a method for the preparation of a porous hollow shell WO.sub.3/WS.sub.2 nanomaterial, comprising: (1) adding a hexavalent tungsten salt to a sol A comprising mesocarbon microbeads, and stirring to obtain a sol B; (2) drying and grinding the sol B, and then heating a resulting powder at 200-500 C. for 0.5-2 hours to obtain a porous hollow shell WO.sub.3 nanocrystalline material; (3) placing the porous hollow shell WO.sub.3 nanocrystalline material obtained by Step 2 and a sulfur powder separately in a vacuum furnace, controlling such that a degree of vacuum is 0.01 to 0.1 MPa and a temperature is 200-500 C., and reacting for 0.5-3 hours to obtain a WO.sub.3/WS.sub.2 porous hollow shell nanocrystalline material. Also provided is a porous hollow shell WO.sub.3/WS.sub.2 nanocrystalline material obtained by the method.