Abstract:
A polymer compound having a phenylcarbazole group, and a polymer electroluminescent device containing the polymer compound are provided to improve hole and electron transport property and to enhance brightness and color reproduction range. A polymer compound having a phenylcarbazole group is represented by the formula 1, 2 or 3, wherein R1 to R11 are identical or different one another and are H, a halogen atom, an alkyl group, an alkoxy group, a cyano group, a nitro group, an acyl group, a substituted or unsubstituted amino group, a substituted or unsubstituted aryl group, or a substituted or unsubstituted hetero ring having at least one halogen, nitrogen, oxygen or sulfur atom as a ring member; X1 to X4 are identical or different one another and are an alkylene group, a substituted or unsubstituted arylene group, a substituted or unsubstituted hetero arylene group, or their combination; Y1 to Y3 are a substituted or unsubstituted C6-C60 aryl group, a substituted or unsubstituted C3-C60 heteroaryl group, or a substituted or unsubstituted fluorene group; a, b, c and d are 0 or 1; and n, m and p are an integer of 1-50,000.
Abstract:
Polyvinylalcohol hydrogel particles are provided to be amorphous irrespective of the degree of hydrolysis, to ensure relatively low specific gravity and increased surface unevenness, and to exhibit improved dispersibility in a contrast medium when the particles are used as an embolizing agent. Polyvinylalcohol hydrogel particles are prepared by dispersing poly(vinyl acetate) microspheres in an aqueous acid solution. The aqueous acid solution comprises 0.1-3 M of hydrochloric acid, 0.1-500 ml of alcohol, and 0.1-300 g of an inorganic salt, based on the aqueous acid solution 1L. The polyvinylalcohol hydrogel particle has an uneven surface. The alcohol is methanol or ethanol. The inorganic salt is sodium sulfate or sodium sulfite.
Abstract:
A method for preparing metal oxide nanopowder is provided to obtain metal oxide nanopowder easily controllable in particle characteristics including particle size and particle size distribution through a simple process at a high yield. A method for preparing metal oxide nanopowder comprises the steps of: mixing and agitating a thermoplastic polymer resin solution with a compound containing at least one kind of metal ion; and heat-treating the mixed solution to obtain nanosized metal oxide powder. The heat treating step is carried out at a 350-800 deg.C. The thermoplastic polymer resin solution comprises 5-30 wt% of a thermoplastic polymer resin. Further, the solvent is selected from a group consisting of water, methanol, ethanol and isopropylalcohol.
Abstract:
A method for preparing titanium dioxide photo-catalytic sol and a method for producing titanium dioxide photo-catalyst are provided to produce a catalyst having an excellent catalytic activity at a visible light band. An agitation process is performed by mixing titanium precursor, metal ion precursor, and nitrogen ion precursor into a solvent, and agitating the mixed matter(S110). A peptization process is performed by mixing the solution formed by the agitation process into an acid or base aqueous solution, and peptizing the mixed matter(S120). Metal ions and nitrogen ions are simultaneously doped in a titanium dioxide lattice formed by the peptization process. Further, the solvent is an alcohol-based solvent, and the metal ion precursor is a metal salt or metal acid selected from Pt, Nb and Au.