In this study, three types of carbon fibres were used, they were ex-polyacrylonitrile carbon fibres with high bulk modulus, ex-polyacrylonitrile fibres with high strength, and vapour grown carbon fibres. All the sampl...In this study, three types of carbon fibres were used, they were ex-polyacrylonitrile carbon fibres with high bulk modulus, ex-polyacrylonitrile fibres with high strength, and vapour grown carbon fibres. All the samples were subjected to a hydrogen adsorption process at room temperature in an over-pressured atmosphere of 25 bars. The adsorption process was monitored through electrical resistivity measurements. As conditioning of the fibres, a chemical activation by acid etching followed by γ-ray irradiation with 60Co radioisotopes was performed. The surface energy was determined by means of the sessile drop test. Both conditioning treatments are supplementary;the chemical activation works on the outer surface and the γ-irradiation works in the bulk material as well. Apparently, the most significant parameter for hydrogen storage is the crystallite size. From this point of view, the most convenient materials are those with small grain size because hydrogen is accumulated mainly in the grain boundaries.展开更多
In this work, different samples of an industrial carbon black are used to study the hydrogen intake from an over pressurized atmosphere and its changes due to alteration of its level of crystallinity produced by γ-ir...In this work, different samples of an industrial carbon black are used to study the hydrogen intake from an over pressurized atmosphere and its changes due to alteration of its level of crystallinity produced by γ-irradiation. The monitoring of the hydrogen adsorption was made by means of thermogravimetric analysis and by measurements of some electrical parameters as the Seebeck coefficient. X-ray diffraction shows that the irradiation diminishes the level of crystalline perfection. These results show interesting possibilities to use carbon black as cheap hydrogen absorbers.展开更多
基金support from the Spanish Ministry of Finances and Competitiveness for support via the Programme ConsoliderIngenio 2010(project CSD 2010-00044).
文摘In this study, three types of carbon fibres were used, they were ex-polyacrylonitrile carbon fibres with high bulk modulus, ex-polyacrylonitrile fibres with high strength, and vapour grown carbon fibres. All the samples were subjected to a hydrogen adsorption process at room temperature in an over-pressured atmosphere of 25 bars. The adsorption process was monitored through electrical resistivity measurements. As conditioning of the fibres, a chemical activation by acid etching followed by γ-ray irradiation with 60Co radioisotopes was performed. The surface energy was determined by means of the sessile drop test. Both conditioning treatments are supplementary;the chemical activation works on the outer surface and the γ-irradiation works in the bulk material as well. Apparently, the most significant parameter for hydrogen storage is the crystallite size. From this point of view, the most convenient materials are those with small grain size because hydrogen is accumulated mainly in the grain boundaries.
基金support from the Spanish Ministry of Finances and Competitivity(MINECO),through the grant of the Consolider-Ingenio 2010 project Nanotherm(CSD2010-00044).
文摘In this work, different samples of an industrial carbon black are used to study the hydrogen intake from an over pressurized atmosphere and its changes due to alteration of its level of crystallinity produced by γ-irradiation. The monitoring of the hydrogen adsorption was made by means of thermogravimetric analysis and by measurements of some electrical parameters as the Seebeck coefficient. X-ray diffraction shows that the irradiation diminishes the level of crystalline perfection. These results show interesting possibilities to use carbon black as cheap hydrogen absorbers.
