Abstract: The present invention relates to a white and color photoexcitation light emitting sheet comprising a substrate, a light source formed on the substrate, and a white and color photoexcitation light emitting layer capable of converting a light emitted from the light source into a light having a different wavelength, where the white and color photoexcitation light emitting layer is fabricated by mixing a matrix polymer, white and color photoexcitation light emitting materials and a solvent, spinning the resulting mixture to prepare an ultrafine composite fiber layer of the matrix polymer/photoexcitation light emitting materials, and thermocompressing the ultrafine composite fiber layer; and a method for fabrication thereof. The white and color photoexcitation light emitting sheet according to the present invention has uniform brightness and color coordinates and exhibits high color reproducibility.

Abstract: A dye-sensitized solar cell having improved photoelectric conversion characteristic includes a metal oxide layer having dye-adsorbed metal oxide nanoparticles, wherein the metal oxide nanoparticles are formed by electrospinning a mixed solution of a metal oxide precursor and a polymer into ultrafine composite fibers, and thermally compressing and sintering the ultrafine composite fibers.

Abstract: The present invention provides a novel hybrid polymer electrolyte, a lithium secondary battery comprising the hybrid polymer electrolyte polymer and their fabrication methods. More particularly, the present invention provides the hybrid polymer electrolyte comprising superfine fibrous porous polymer matrix with particles having diameter of 1-3000 nm, polymers and lithium salt-dissolved organic electrolyte solutions incorporated into the porous polymer matrix. The hybrid polymer electrolyte has advantages of better adhesion with electrodes, good mechanical strength, better performance at low and high temperatures, better compatibility with organic electrolytes of a lithium secondary battery and it can be applied to the manufacture of lithium secondary batteries.

Abstract: There is provided a metal oxide having a continuous nano-fiber network structure as a negative active material for a secondary battery. A method for fabricating such negative active material for a secondary battery comprises spinning a mixed solution of a metal oxide precursor and a polymer onto a collector to form composite fibers mixed with the metal oxide precursor and the polymer, thermally compressing or thermally pressurizing the composite fibers, and thermally treating the thermally compressed or thermally pressurized composite fibers to remove the polymer from the composite fiber.

Abstract: The present invention discloses an improved electrode for a supercapacitor and a method of preparation thereof. The inventive electrode comprises a collector, a carbon substrate disposed on the collector comprising ultrafine carbon fibers having a specific surface area of at least 200 m2/g (BET) and a d002 value of 0.36 nm or less, and a metal oxide thin layer formed on the carbon substrate. The electrode of the subject invention retains a high specific capacitance during high-speed charging and discharging cycles.

Abstract: A method for fabricating an ultra-sensitive metal oxide gas sensor is disclosed, which comprises the steps of spinning a mixture solution including a metal oxide precursor and a polymer onto a sensor electrode to form a metal oxide precursor-polymer composite fiber; thermally compressing or thermally pressurizing the composite fiber; and thermally treating the thermally compressed or thermally pressurized composite fiber to remove the polymer from the composite fiber. Since the gas sensor includes a macro pore between nanofibers and a meso pore between nano-rods and/or nano-grains, gas diffusion and surface area can be maximized. Also, the ultra-sensitive sensor having high stability in view of mechanical, thermal, and electrical aspects can be obtained through rapid increase of adhesion between the metal oxide thin layer and the sensor electrode.

Abstract: The present invention provides a lithium secondary battery and its fabrication method. More particularly, the present invention provides a lithium secondary battery comprising a super fine fibrous porous polymer separator film and its fabrication method, wherein the porous polymer separator film is fabricated by the following process: a) melting at least one polymer or dissolving at least one polymer with organic solvents to obtain at least one polymeric melt or at least one polymeric solution; b) adding the obtained polymeric melt or polymeric solution to barrels of an electrospinning machine; and c) discharging the polymeric melt or polymeric solution onto a substrate using a nozzle to form a porous separator film. The lithium secondary battery of the present invention has the advantages of better adhesion with electrodes, good mechanical strength, better performance at low and high temperatures, better compatibility with organic electrolyte solution of a lithium secondary battery.

Abstract: The present invention discloses an ultrafine graphitic carbon fiber and a preparation method thereof. An ultrafine fiber having a diameter of 1 to 3000 nm is prepared by electrospinning a halogenated polymer solution containing a metal compound inducing graphitization. In carbonization, an ultrafine porous graphitic carbon fiber having a large specific surface area, micropores and macropores is prepared by the graphitization by a metal catalyst generated from the metal compound. The ultrafine carbon fiber can be used as a carbon material for storing hydrogen, an adsorbing material of biochemically noxious substances, an electrode material of a supercapacitor, a secondary cell and a fuel cell, and a catalyst carrier material.

Abstract: A titanium dioxide nanorod having anisotropy and a preparation method thereof in which, particularly, an ultrafine composite fiber of polymer and titanium dioxide precursor and a single crystal titanium dioxide nanorod using a phase separation are prepared, wherein a mixed solution containing titanium dioxide precursor, polymer which is compatible with the precursor and solvent is prepared, the mixed solution is electrospun to form titanium dioxide polymer composite fiber containing ultrafine fibril structure therein by the phase separation between the titanium dioxide precursor and the polymer, the composite fiber is heat-pressed, and the polymer material is removed from the composite fiber, so as to obtain titanium dioxide nanorod, which can be used as dye-sensitized solar cells, various sensors, and photocatalysts.

Abstract: A supercapacitor having a metal oxide electrode and a method for preparing the same. The method comprises preparing a substrate composed of a current collector and a titanium dioxide ultrafine fiber matrix layer formed on the current collector, and electrochemically depositing a metal oxide thin film layer onto the substrate by a constant current potentiometry or a cyclic voltammetric method. Since the metal oxide is uniformly deposited on the substrate having a wide specific surface area with the titanium dioxide ultrafine fiber, a bonding material or a conductive particle need not to be added to the capacitor electrode. Therefore, a resistance of the capacitor electrode is prevented from being increased, and thus a capacitance of the capacitor electrode is prevented from being decreased.

Abstract: A complex membrane for an electrochemical device such as a lithium secondary battery, its manufacturing method, and an electrochemical device having the complex membrane are disclosed. The complex membrane includes a micro-porous polyolefin membrane, and a web-phase porous membrane united to at least one side of the micro-porous polyolefin membrane and composed of nano-fibers. Since the complex membrane is capable of absorbing an electrolyte uniformly, it greatly improves performance of a battery when being used for an electrochemical device. In addition, owing to excellent mechanical strength and good binding capacity to an electrode, it helps to increase a process rate for manufacturing the battery.

Abstract: A dye-sensitized solar cell comprising a semiconductor electrode comprising electrospun ultra-fine titanium dioxide fibers and fabrication method thereof are disclosed. The dye-sensitized solar cell comprises a semiconductor electrode comprising an electrospun ultra-fine fibrous titanium dioxide layer, a counter electrode and electrolyte interposed therebetween. A non-liquid electrolyte such as polymer gel electrolyte or the like having low fluidity, as well as the liquid electrolyte, can be easily infiltrated thereinto. In addition, electrons can be effectively transferred since titanium dioxide crystals are one-dimensionally arranged.

Abstract: Disclosed is a process for preparing a homogeneous cellulose solution which is capable of, forming a mixture where a cellulose pulp powder is mixed and swollen with a liquid NMMO hydrate solvent supercooled under a melting point and subjecting the mixture to a dissolution treatment, thereby producing a homogeneous cellulose solution having a substantially low decomposition characteristic. The process produces a cellulose pulp mixing powder that is first swollen in a liquid NMMO solvent supercooled under a melting point by minimizing the dissolution of cellulose by the liquid NMMO solvent and maximizing the swelling thereof by the liquid NMMO solvent, thereby resulting in a maximum homogeneity of the solution and maintains the minimized decomposition states of the cellulose and the NMMO solvent, thereby resulting in the improvement of productivity and the simplicity of the process.

Abstract: The present invention relates to an apparatus of polymer web by electrospinning process and manufacturing method thereof, which can manufacture porous polymer web using an electrospinning method. The method for manufacturing porous polymer web by electrospinning process includes the steps of: forming, pressurizing and supplying at least one or more kinds of polymer materials in a liquid state; and discharging and piling the polymer materials to a collector through one or more charged nozzles, the collector being located under the nozzles and charged to have a polarity opposed to the polarity of the charged nozzles, the collector moving in a prescribed speed.

Abstract: The present invention relates to an apparatus of polymer web by electrospinning process and manufacturing method thereof, which can manufacture porous polymer web using an electrospinning method. The method for manufacturing porous polymer web by electrospinning process includes the steps of: forming, pressurizing and supplying at least one or more kinds of polymer materials in a liquid state; and discharging and piling the polymer materials to a collector through one or more charged nozzles, the collector being located under the nozzles and charged to have a polarity opposed to the polarity of the charged nozzles, the collector moving in a prescribed speed.

Abstract: Disclosed is a method for preparing a thin fiber-structured polymer web suitable for a high-speed and large-scale production using electrospinning.

Abstract: The present invention is directed to a process of atom (or group) transfer radical polymerization for the synthesis of novel homopolymer or a block or graft copolymer, optionally containing at least one polar group, with well defined molecular architecture and narrow polydipersity index, in the presence of an initiating system comprising (i) an initiator having a radically transferrable atom or group, (ii) a transition metal compound, and (iii) a ligand, the present invention is also directed to the synthesis of a macromolecule having at least two halogen groups which can be used as a macroinitiator component (i) to subsequently form a block or graft copolymer by an atom or group transfer radical polymerization process; the present invention is also directed to a process of atom or group transfer radical polymerization for the synthesis of a branched or hyperbranched polymer; in addition, the present invention is directed to a process of atom or group transfer radical polymerization for the synthesis of a mac

Abstract: A simple method of preparing a homogeneous cellulose solution is disclosed, which comprises the steps of (a) preparing fibrillar cellulose powder; (b) injecting a molten liquid tertiary amine oxide solvent into a twin screw extruder; (c) feeding the cellulose powder of step (a) into a section of the twin screw extruder where the molten liquid tertiary amine oxide solvent fed in step (b) produces a well swollen paste with the cellulose powder fed in step (c); (d) dissolving the well swollen cellulose paste in the following melting sections in the twin screw extruder; and (e) stabilizing the solution obtained in step (d) in a storage tank.

Abstract: The present invention is directed to a process of atom (or group) transfer radical polymerization for the synthesis of novel homopolymer or a block or graft copolymer, optionally containing at least one polar group, with well defined molecular architecture and narrow polydispersity index, in the presence of an initiating system comprising (i) an initiator having a radically transferrable atom or group, (ii) a transition metal compound, and (iii) a ligand; the present invention is also directed to the synthesis of a macromolecule having at least two halogen groups which can be used as a macroinitiator component (i) to subsequently form a block or graft copolymer by an atom or group transfer radical polymerization process; the present invention is also directed to a process of atom or group transfer radical polymerization for the synthesis of a branched or hyperbranched polymer; in addition, the present invention is directed to a process of atom or group transfer radical polymerization for the synthesis of a ma

Abstract: The present invention is directed to a process of atom (or group) transfer radical polymerization for the synthesis of novel homopolymer or a block or graft copolymer, optionally containing at least one polar group, with well defined molecular architecture and narrow polydispersity index, in the presence of an initiating system comprising (i) an initiator having a radically transferrable atom or group, (ii) a transition metal compound, and (iii) a ligand; the present invention is also directed to the synthesis of a macromolecule having at least two halogen groups which can be used as a macroinitiator component (i) to subsequently form a block or graft copolymer by an atom or group transfer radical polymerization process; the present invention is also directed to a process of atom or group transfer radical polymerization for the synthesis of a branched or hyperbranched polymer; in addition, the present invention is directed to a process of atom or group transfer radical polymerization for the synthesis of a ma