• Proceedings of the Membrane Society of Korea Conference
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• 1999.04a
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• pp.39-41
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• 1999

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.265-270
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• 2014

Among the Ruddlesden-Popper series, $La_4Ni_3O_{10}$ has received widespread attention as a promising cathode material by reason of its favorable properties for realizing high performance of intermediate temperature solid oxide fuel cells (IT-SOFCs). The $La_4Ni_3O_{10}$ cathode is prepared using the facile sol-gel method by employing tri-blockcopolymer (F127) to obtain a single phase in a short sintering time. There are no reactions between the $La_4Ni_3O_{10}$ cathode and the $Ce_{0.9}Gd_{0.1}O_{2-\delta}$ (GDC) electrolyte upon sintering at $1000^{\circ}C$, indicating that the $La_4Ni_3O_{10}$ cathode has good chemical compatibility with the GDC electrolyte. The maximum electrical conductivity of $La_4Ni_3O_{10}$ reaches approximately 240 S $cm^{-1}$ at $100^{\circ}C$ and gradually decreases with increasing temperaturein air atmosphere. The area specific resistance value of $La_4Ni_3O_{10}$ composite with 40 wt% GDC is $0.435{\Omega}cm^2$ at $700^{\circ}C$. These data allow us to propose that the $La_4Ni_3O_{10}$-GDC composite cathode is a good candidate for IT-SOFC applications.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.276-276
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• 2013

Time-Of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) and Atomic Force Microscopy (AFM) are the useful instruments to measure nanostructures of material surfaces. Surface pattern formation in blending homopolymer and diblock copolymer films was investigated as a function of film thickness and annealing conditions. In this study, surface structures of blending homopolymer [deuterated polystyrene (Mn 20,000), poly (methyl methacrylate) (Mn 18,000)] and diblock copolymer [Poly (deuteratedstyrene(d8)-b-methyl methacrylate) (Mn 19,500-18,100)] films were observed. The AFM result indicated that the nanostructures and film thickness depended on temperature, concentration and solvent. TOF-SIMS depth profiling was obtained for the lamellar morphology of symmetric dPS-b-PMMA which is found to orient parallel to the surface of the substrate. Elemental and molecular depth profiles measured in the negative ion mode by a Cs+ primary ion beam demonstrate variations in hydrogen, deuterium, carbon, oxygen, hydrocarbons and deuterated hydrocarbons within the diblock copolymer according to the depth.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.11a
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• pp.63-64
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• 2007

Polystyrene-block-polymethyl methacrylate (PS-b-PMMA) can pattern nanoscale structures over large areas. However these patterns have a short-range order. These short-range order limits their utility in some applications. Consequently, we have to overcome this limitation of block-copolymer. In this study we added a electrical field to the standard block-copolymer patterning method for long-range ordered arrays of nanostructures. This method is conformed by annealing a block copolymer with applied voltages. It is very simple method that do not have any additional hour. In this reason it can be applied easily for other nanostructure fabrications. This method opens up a new route to the controlled phase separation of block copolymers with precise place of the nanostructures.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.2
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• pp.144-149
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• 2017

A proton-conducting bisphenylpropaned sulfonated fluorinated blockcopolymer (BPSFBC) was synthesized. Five kinds of polymer electrolyted composite membranes were preparated by incorporating silica ($SiO_2$) with various weight ratio. And their characteristics were investigated by FT-IR (fourier transform infrared), $^1H-NMR$ ($^1H$ nuclear magnetic resonance), TGA (thermogravimetric analysis), water uptake, FE-SEM (field emission scanning electron microscopes), and ion conductivity properties. The water uptake and ion conductivity were increased until 9 wt% $SiO_2$, and then decreased. The maximum proton conductivity equal to $52mScm^{-1}$ was measured for the BPSFBC/$SiO_2$-9 composite membrane at $90^{\circ}C$ and 100% relative humidity. From the measured results, it is distinct that the manufactured composite membrane BPSFBC/$SiO_2$-9 can be considered as a polymer membrane suitable for a fuel cell electrolyte.

• Journal of Pharmaceutical Investigation
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• v.30 no.4
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• pp.259-266
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• 2000

Vitamin A palmitate, an oily drug which has low chemical stability and is poorly absorbed in the intestine, was formulated into a novel powdered dosage form. This is designated as a redispersible dry emulsion by freeze-drying technique. Before preparing a dry emulsion, vitamin A palmitate oil in solid in water (O/S/W) emulsion with soybean oil and coconut oil using Aerosil 200 as an emulsion stabilizer and polyoxyethylene-polyoxypropylene-blockcopolymer (Pluronic F68) as a surfactant was prepared. The resultants of the stability tests indicated that vitamin A palmitate O/S/W emulsion was improved on increasing the oil content of the formulation. The resultant dry emulsion particles have a good stabilities and free flow properties and readily released the oily droplets to form stable emulsions on rehydration. The drug releasing property from the resultant dry emulsion particles was dependent on factors such as amount of oily carrier(soybean oil) and surfactant(Pluronic F68) formulated. Above 80% of vitamin A palmitate content was released from the dry emulsion for 1 hour. It was deduced that vitamin A palmitate dry emulsion was definitely suitable for oral administration, since small droplets of vitamine A palmitate from the dry emulsion may alter the drug absorption profile resulting in bioavailability enhancement.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.727-731
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• 2008

Mesoporous Pt-Au alloy films were successfully fabricated on ITO-coated glass by electrodeposition method using tri-blockcopolymer (P123) as a templating agent. The electrolyte consisted of 10 mM hydrogen hexachloroplatinate ($H_2PtCl_6$), 10 mM hydrogen tetrachloroaurate ($HAuCl_4$), and proper amount of P123. For comparison, control samples were electrodeposited without $HAuCl_4$ and P123. Film composition was determined by EDS(Energy Dispersive X-ray Spectroscopy), and the mesoporous structure was confirmed by TEM(Transmission Electron Microscopy). SEM(Scanning Electron Microscopy) was utilized to examine surface morphology, and it was observed that the addition of P123 affected the particle growth, resulting in the significant change of surface morphology. Methanol oxidation and CO oxidation were carried out to investigate electrocatalytic activities of synthesized samples. It was observed that the catalytic activity was strongly dependent on the film compositions. Compared with nonporous electrode prepared without P123 templating, mesoporous films prepared with P123 templating showed much higher catalytic activities and stability for both methanol oxidation and CO oxidation. These enhanced electrocatalytic activities were due to the high surface area and facilitated charge transfer of mesoporous films.