Abstract: A colloidal crystal having a diamond lattice structure, including: a first layer in which a first plurality of particles are arranged to form a plane of a face-centered cubic lattice structure; a second layer in which a second plurality of particles are arranged on the first layer in contact with the first particles; and a third layer in which a third plurality of particles are arranged on the second layer in contact with the second particles, wherein the colloidal crystal includes at least one layer of each of the first layer, the second layer and the third layer.

Abstract: [Object] To provide a decorative aqueous composition that includes particles formed from opal-type colloidal crystals uniformly and stably dispersed in an aqueous dispersion medium, and exhibits a structural color due to interference of light, and to provide a method for producing the decorative aqueous composition. [Solution] The decorative aqueous composition of the present invention contains particles of opal-type colloidal crystals dispersed in an aqueous dispersion medium in which a polymer is dissolved. The particles of the opal-type colloidal crystals are made from hydrophilic colloidal particles having an average particle diameter ranging from 10 nm to 1000 nm with a variation coefficient of the particle diameter being within 20%. Therefore, the decorative aqueous composition of the present invention contains opal-type colloidal crystals uniformly and stably dispersed in an aqueous dispersion medium, and exhibits a structural color due to interference of light.

Abstract: [Object] Provided are a “eutectic colloidal crystal” which is an aggregate of plural kinds of colloidal crystals having different lattice constants, a solidified body of the eutectic colloidal crystal, and methods for producing them. [Resolution means] The eutectic colloidal crystal of the present invention contains two or more kinds of colloidal crystals composed of substantially monodispersed colloidal particles having different particle sizes. This eutectic colloidal crystal is obtained by providing a colloidal dispersion of two or more kinds of colloidal particles having different particle sizes, and a polymer which will not substantially adsorb to the colloidal particles (the coefficient of variation in particle size of these colloidal particles is less than 20%) dissolved in a dispersion medium (dispersion preparation process), and allowing the colloidal dispersion to stand (eutectoid process).

Abstract: [Problem] To provide a method for producing a colloidal crystal, wherein the method is easily controlled and is capable of dealing with a wide range of types of colloidal particle. [Solution] The method for producing a colloidal crystal in the present invention is characterized by comprising a preparation step of preparing a colloidal dispersion liquid, in which colloidal particles are dispersed in a liquid comprising an ionic surfactant and a colloidal crystal can be formed due to temperature changes, and a crystallization step of formation of a colloidal crystal by changing the temperature of the colloidal dispersion liquid from a temperature region in which the colloidal crystal is not formed to a temperature region in which the colloidal crystal is formed.

Abstract: [Object] Provided are a “eutectic colloidal crystal” which is an aggregate of plural kinds of colloidal crystals having different lattice constants, a solidified body of the eutectic colloidal crystal, and methods for producing them. [Resolution means] The eutectic colloidal crystal of the present invention contains two or more kinds of colloidal crystals composed of substantially monodispersed colloidal particles having different particle sizes. This eutectic colloidal crystal is obtained by providing a colloidal dispersion of two or more kinds of colloidal particles having different particle sizes, and a polymer which will not substantially adsorb to the colloidal particles (the coefficient of variation in particle size of these colloidal particles is less than 20%) dissolved in a dispersion medium (dispersion preparation process), and allowing the colloidal dispersion to stand (eutectoid process).

Abstract: The present invention provides an acrylic resin composition containing a polycrystal of colloidal particles of silicon oxide in an acrylic resin that is formed by curing an acrylic monomer liquid at room temperature and/or an acrylic oligomer liquid at room temperature, wherein a mean distance between the colloidal particles in the polycrystal is 140 to 330 nm. The size of the single crystal that constitutes the polycrystal can be controlled by adjusting the content of silicon oxide and/or the additive amount of impurities. An architectural material, a fashion accessory, and an optical material are provided that are formed by using the acrylic resin composition.

Abstract: Provided is a process for producing colloidal crystals from which a large single crystal reduced in lattice defects and unevenness can be easily produced at low cost without fail. The process for colloidal crystal production comprises: preparing a colloidal polycrystal dispersion in which colloidal crystals precipitate at a given temperature (preparation step); introducing into a vessel The colloidal polycrystal dispersion in the state of containing fine colloidal polycrystals precipitated (introduction step); and melting the colloidal polycrystals and then recrystallizing the molten polycrystals (recrystallization step). The crystals thus obtained have fewer lattice defects and less unevenness than the original polycrystals.

Abstract: [Problem] To provide a method for producing a colloidal crystal, wherein the method is easily controlled and is capable of dealing with a wide range of types of colloidal particle. [Solution] The method for producing a colloidal crystal in the present invention is characterized by comprising a preparation step of preparing a colloidal dispersion liquid, in which colloidal particles are dispersed in a liquid comprising an ionic surfactant and a colloidal crystal can be formed due to temperature changes, and a crystallization step of formation of a colloidal crystal by changing the temperature of the colloidal dispersion liquid from a temperature region in which the colloidal crystal is not formed to a temperature region in which the colloidal crystal is formed.

Abstract: The present invention provides an acrylic resin composition containing a polycrystal of colloidal particles of silicon oxide in an acrylic resin that is formed by curing an acrylic monomer liquid at room temperature and/or an acrylic oligomer liquid at room temperature, wherein a mean distance between the colloidal particles in the polycrystal is 140 to 330 nm. The size of the single crystal that constitutes the polycrystal can be controlled by adjusting the content of silicon oxide and/or the additive amount of impurities. An architectural material, a fashion accessory, and an optical material are provided that are formed by using the acrylic resin composition.

Abstract: Provided is a process for producing colloidal crystals from which a large single crystal reduced in lattice defects and unevenness can be easily produced at low cost without fail. The process for colloidal crystal production comprises: preparing a colloidal polycrystal dispersion in which colloidal crystals precipitate at a given temperature (preparation step); introducing into a vessel The colloidal polycrystal dispersion in the state of containing fine colloidal polycrystals precipitated (introduction step); and melting the colloidal polycrystals and then recrystallizing the molten polycrystals (recrystallization step). The crystals thus obtained have fewer lattice defects and less unevenness than the original polycrystals.

Abstract: When a piezoelectric element 3 applies an external force to a plastic photonic crystal, the photonic crystal deforms, and accordingly, the photonic band gap easily changes. When the photonic band gap changes, transmission of light with a specific wavelength is limited. Therefore, light with a desired wavelength is outputted from the photonic crystal 2 upon sufficient tuning, and extracted to the outside through an output window 6. In the present invention, a plastic photonic crystal 2 which can achieve sufficient wavelength tuning although it is small is used, and elements are unitized, so that the entire wavelength tunable light source unit is downsized.

Abstract: Gelled colloidal crystals obtained by ultraviolet irradiation gelation means proposed so far in the art are inadequate in term of homogeneous gelation as far as their deep portions, and gelled colloidal crystals obtained by use of gelation means relying upon a light source in the visible light range in place of that ultraviolet irradiation has several problems such as difficulty with selection of polymerization initiators and generation of gas bubbles. The object of the invention is to provide a colloidal crystal gelled homogeneously to within, from which those problems are eliminated. To this end, a colloidal solution using an aqueous liquid as a disperse medium with a monomer or macromer added thereto and camphorquinone, riboflavin or their derivative contained therein as a polymerization initiator is irradiated with light having a wavelength component in the range of at least 400 nm to 500 nm for the purpose of gelation, thereby providing a solution to the aforesaid problems.

Abstract: A fiber coupling device comprises fixing parts 1V, to which the respective ends of two optical fibers 5 and 6 are fixed, photonic crystal 2, disposed inside the light path of light that propagates across the abovementioned ends, and external force application means 3, which applies an external force to photonic crystal 2. When an external force is applied by external force application means 3 to photonic crystal 2 while light is being propagated inside one optical fiber 5, the photonic band gap of photonic crystal 2 changes and light of a wavelength that is in accordance with this photonic band gap is output from the other optical fiber 5.

Abstract: A photonic crystal 2 with plasticity is arranged by making microspheres of silica or barium titanate or air bubbles be contained in a gel substance. When an external force is applied to this photonic crystal, photonic crystal 2 deforms and the photonic band gap is readily changed thereby. When the photonic band gap changes, the passage of light of a specific wavelength is restricted. Light of a desired wavelength is thus output from photonic crystal 2. With this invention, this wavelength can be varied readily by means of an external force.

Abstract: When a piezoelectric element 3 applies an external force to a plastic photonic crystal, the photonic crystal deforms, and accordingly, the photonic band gap easily changes. When the photonic band gap changes, transmission of light with a specific wavelength is limited. Therefore, light with a desired wavelength is outputted from the photonic crystal 2 upon sufficient tuning, and extracted to the outside through an output window 6. In the present invention, a plastic photonic crystal 2 which can achieve sufficient wavelength tuning although it is small is used, and elements are unitized, so that the entire wavelength tunable light source unit is downsized.

Abstract: A photonic crystal 2 with plasticity is arranged by making microspheres of silica or barium titanate or air bubbles be contained in a gel substance. When an external force is applied to this photonic crystal, photonic crystal 2 deforms and the photonic band gap is readily changed thereby. When the photonic band gap changes, the passage of light of a specific wavelength is restricted. Light of a desired wavelength is thus output from photonic crystal 2. With this invention, this wavelength can be varied readily by means of an external force.

Abstract: A fiber coupling device comprises fixing parts 1V, to which the respective ends of two optical fibers 5 and 6 are fixed, photonic crystal 2, disposed inside the light path of light that propagates across the abovementioned ends, and external force application means 3, which applies an external force to photonic crystal 2. When an external force is applied by external force application means 3 to photonic crystal 2 while light is being propagated inside one optical fiber 5, the photonic band gap-of photonic crystal 2 changes and light of a wavelength that is in accordance with this photonic band gap is output from the other optical fiber 5.