Publications by authors named "Hai Woong Park"

We investigate the copper-wear-protective effects of graphene and boron nitride in single asperity sliding contact with a stiff diamond-coated atomic force microscopy (AFM)-tip. We find that both graphene and boron nitride retard the onset of wear of copper. The retardment of wear is larger with boron nitride than with graphene, which we explain based on their respective out-of-plane stiffnesses.

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Ordered mesoporous carbon (OMC) was sulfonated at different temperature (OMC-SO3H-X, X = 125, 150, 175, 200, and 225 degrees C) in order to provide acid sites to OMC. Palladium catalysts were then supported on OMC-SO3H-X by an incipient wetness impregnation method for use in the catalytic decomposition of 2,3-dihydrobenzofuran to monocyclic compounds. 2,3-Dihydrobenzofuran was used as a lignin model compound for representing β-5 linkage of lignin.

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Polyetheretherketone (PEEK) is considered as a substitute for metallic implant materials due to its extremely low elastic modulus (3-4 GPa). Despite its good mechanical properties, PEEK exhibits a slow integration with the bone tissue due to its relatively inert surface and low biocompatibility. We introduced a dual modification method, which combines the laser and plasma surface treatments to achieve hierarchically patterned PEEK surfaces.

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Cesium-exchanged heteropolyacid (Cs(x)H3.0-xPW12O40) was impregnated onto activated carbon aerogel (ACA) with a variation of cesium content (X = 2.0, 2.

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Graphene-containing carbon aerogel was prepared by a polycondensation of resorcinol with formaldehyde using chemically exfoliated graphene oxide in ambient conditions, and its electrochemical performance as an electrode for supercapacitor was examined. The effect of pH in the preparation of RFGO (resorcinol-formaldehyde and graphene oxide) solution on the physical and electrochemical properties of graphene-containing carbon aerogel was investigated. For comparison, graphene-free carbon aerogel was also prepared.

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Copper-containing mesoporous carbon (Cu-MC) was prepared by a single-step surfactant-templating method. For comparison, copper-impregnated mesoporous carbon (Cu/MC) was also prepared by a surfactant-templating method and a subsequent impregnation method. Rhenium catalysts supported on copper-containing mesoporous carbon and copper-impregnated mesoporous carbon (Re/Cu-MC and Re/Cu/MC, respectively) were then prepared by an incipient wetness method, and they were applied to the liquid-phase hydrogenation of succinic acid to 1,4-butanediol (BDO).

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Carbon aerogel (CA) was prepared by a sol-gel polymerization of resorcinol and formaldehyde, and a series of activated carbon aerogels (ACA-KOH-X, X = 0, 0.3, 0.7, 1, and 2) were then prepared by a chemical activation using different amount of potassium hydroxide (X represented weight ratio of KOH with respect to CA).

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