A novel metal oxide nanotube made only of a metal oxide is produced by the use of a helical fiber (Japanese Patent Application No. 2001-239014). The metal oxide nanotube has a pore diameter distribution having two peak pore diameters in the ranges of 1-2 nm and 3-7 nm respectively, constitutes a double helix, takes the form of a hollow cylinder, and is made only of a metal oxide which may contain hydroxyl groups. The nanotube can be produced by a process comprising the step of dissolving a compound (1) represented by the general formula (1) and a compound (2) represented by the general formula (2): (1) (2) [wherein A and B may be the same or different from each other and are each a sugar residue; R is alkyl; and R’ is hydrogen or alkyl] in water or a mixture of water and alcohol and allowing the resulting solution to stand; the step of adding a precursor of a metal oxide to the solution; the step of adding a catalyst for converting the precursor into a metal oxide; and the step of firing the gel formed in the preceding step. The nanotube exhibits an extremely high hydrogen occlusion capacity.

Metal oxide nanotube and process for production thereof

PROBLEM TO BE SOLVED: To provide a method for producing simply and in a short time a silica nanotube associated product which is produced by highly integrating silica nanotubes having small outer diameters and excellent in monodispersity.SOLUTION: The method for producing the silica nanotube associated product comprises: a step (I) of hydrolyzing polyoxazoline in an acidic condition to obtain a polyethylene imine hydrochloride powder; a step (II) of dissolving the hydrochloride powder obtained in the step (I) in water to obtain an aqueous solution of polyethylene imine hydrochloride; a step (III) of adding a basic compound to the aqueous solution obtained in the step (II) to obtain a crystalline filament associated product of polyethylene imine; a step (IV) of separating the crystalline filament associated product of polyethylene imine obtained in the step (III); a step (V) of dispersing the crystalline filament associated product of polyethylene imine separated in the step (IV) in an aqueous medium and adding a silica source to obtain a composite nanofiber associated product composed of a polyethylene imine core and silica covering the core; and a step (VI) of heating and firing the composite nanofiber associated product obtained in the step (V) to remove the inner polyethylene imine core and developing a hollow structure.

Method for producing silica nanotube associated product

PROBLEM TO BE SOLVED: To provide a dispersion prepared by dispersing fibrous hollow silica fine particles having a low refractive index and excellent film forming property in a dispersion medium, and an antireflection film forming composition containing the silica fine particles. SOLUTION: The fibrous hollow silica fine particle dispersion is prepared by dispersing the fibrous hollow silica fine particles having an average particle diameter in a range of 5-500 nm, a fiber form and a hollow structure in the dispersion medium. The fibrous hollow silica fine particles preferably have (a) an average particle diameter in a range of 5-500 nm, (b) a major axis to minor axis ratio (major axis/minor axis) in a range of 1.5-10, (c) a BET specific surface area in a range of 5-600 m 2 /g, and a refractive index in a range of 1.20-1.40. COPYRIGHT: (C)2009,JPO&INPIT

Fibrous hollow silica fine particle dispersion, fibrous hollow silica fine particles, antireflection film forming composition containing the fine particles, and substrate with antireflection film

PROBLEM TO BE SOLVED: To provide a new technology for forming a nanofiber of a metal oxide represented by silica in an aqueous solution. SOLUTION: In an aprotic polar solvent solution containing a single-strand β-1,3-glucan (e. g. sizofiran), a metal alkoxide is mixed with water, and a sol-gel reaction is promoted to prepare a composite wherein the nanofiber of the metal oxide is incorporated into a hydrophobic interior space of β-1,3-glucan. When preparing silica as the metal oxide, trimethoxy propyl silane and dimethyl sulfoxide are preferably used as the raw material and the aprotic polar solvent, respectively. COPYRIGHT: (C)2006,JPO&NCIPI

Metal oxide nanofiber/polysaccharide composite

PROBLEM TO BE SOLVED: To provide a new organic inorganic composite structure utilizing a liquid crystal structure. SOLUTION: This composite structure is characterized in that silica is contained in a discotic structure in which columns comprising piled disk-like molecules (for example, triphenylene derivative molecules) are two-dimensionally regularly arranged. The method for producing the composite structure comprises preparing a reaction solution comprising the disk-like molecules, a silica source, a sol-gel reaction catalyst and water, subjecting the solution to a sol-gel reaction, coating a substrate with the reaction solution, before the reaction solution is perfectly gelled, and then drying the coated substrate to form the thin coating film. The disk-like molecules can be removed from the composite structure to obtain the porous silica (mesoporous silica). COPYRIGHT: (C)2003,JPO

Organic inorganic composite structure and method for producing the same

PROBLEM TO BE SOLVED: To obtain a new organic-inorganic composite material and a new inorganic material by using an organic low molecule gel as a template SOLUTION: This organic-inorganic composite material having a cylindrical structure which has a size of nanometer order and whose inner and outer side layers comprise an organic molecule and a metal oxide, respectively, is obtained by forming the gel of the organic low molecule in a mixture liquid obtained from a sol-gel reaction solution containing the precursor of the metal oxide and the organic low molecule which has an ionic site and can form the gel in an organic solvent or its mixture solvent with water, and then retaining the gel-formed system to polymerize the metal oxide A hollow fiber-like metal oxide can be obtained by removing the organic low molecule from the organic- inorganic composite material The organic low molecule includes a cholesterol derivative having an ionic site and an azobenzene site as a preferable example The metal oxide includes silica

Organic-inorganic composite material having cylindrical structure, hollow metal oxide, and their production

PROBLEM TO BE SOLVED: To provide a new low molecular weight gelling agent capable of forming a good gel both in an organic solvent and water at a low concentration. SOLUTION: This gelling agent consisting of a saccharide derivative having an azonaphthol structure is expressed by the general formula (I) (wherein, R1 is a saccharide residue).

New gelling agent consisting of saccharide derivative

PROBLEM TO BE SOLVED: To provide a new technique for producing an inorganic porous material by utilizing a bio-related substance as a mold. SOLUTION: This method for producing a hollow fibrous silica contains a process removing by holding collagen (preferably collagen of type I) and alkoxysilane (e.g. tetraethoxysilane) in an aqueous solution having neutral pH and added with a salt at a normal temperature, depositing silica on the surface of a collagen fiber, freeze-drying and baking. By the process, a hollow fibrous silica in which a hollow part having 25-50 nm inner diameter inside a cylindrical shape having 50-100 nm outer diameter, especially composed of a bundle of plural hollow silica hollow fibers having about 3 nm inner diameter of the hollow part.

Hollow fibrous silica and its production

PROBLEM TO BE SOLVED: To obtain a structure in which a metal except a structural metal is fixed to a spiral metal oxide (e.g. silica) by bringing an organic low molecular gel as a mold. SOLUTION: This organic inorganic complex having a spiral double cylindrical structure the inside of which is a cholesterol derivative and the outside of which is a metal oxide is obtained by forming and maintaining a gel of the cholesterol derivative in a mixture solution of a cholesterol derivative enclosing a metal derived from a metal salt prepared by dissolving an azacrown ring-containing cholesterol derivative expressed by general formula I ((n) is 0 or 1; and X is either one of functional groups expressed by formula II) in a solution of the metal salt with a sol-gel reaction solution containing a precursor of the metal oxide to proceed polymerization of the metal oxide. The hollow fiber-like cylindrical spiral metal oxide on the surface of which the metal other than the metal oxide-constituting metal is fixed by removing the cholesterol derivative from the aforesaid organic inorganic complex.

Organic inorganic complex having spiral structure, metal oxide and method for production thereof

PROBLEM TO BE SOLVED: To provide a gelling agent of an organic solvent, capable of being applied to a wide kind of organic solvents to form a strong gel. SOLUTION: This gelling agent of the organic solvent comprises a cholesterol derivative represented by general formula (1) (wherein, one of R1 and R2 is a sugar residue, and the other is a hydrogen atom. Preferably R1 is the sugar residue containing a pyranose ring having at least one axial hydroxy group, and especially preferably the sugar is a monosaccharide selected from α- galactose, β-galactose, α-mannose and α-glucose).

Shinkai Seiji

Papers

Organic-inorganic composite material having cylindrical structure, hollow metal oxide, and their production

New gelling agent consisting of saccharide derivative

Hollow fibrous silica and its production

Organic inorganic complex having spiral structure, metal oxide and method for production thereof

Gelling agent of organic solvent comprising compound having cholesterol and sugar moiety