Anarandray et Tanindrazana à Madagascar (l'identité des migrants Betsileo en Imerina pendant la période coloniale (1895-1960))

PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

Solubilité des gaz dans les nanoliquides

nationa

Enhanced H 2

International audienceHydrogen uptake at 298 K and 30 bar in hybrid sorbents consisting of n-hexane confined in MIL-101 is found to be 22 times larger than in sole n-hexane. The enhanced solubility in MIL-101, found to be 3 times larger than in mesoporous silica of similar pore size, highlights the key roles played by surface chemistry and accessible surface area

Enhanced H 2

INGENIERIE+SCL:LHO:MPE:DFAThe hydrogen uptake in hybrid sorbents consisting of n-alkane solvents confined in mesoporous silica aerogel is measured at different temperatures from 273 to 313 K and pressures up to 40 bar. An apparent oversolubility" effect is observed as the H-2 uptake in the hybrid sorbents is much larger than that in bulk solvents. The H-2 uptake in the hybrid sorbents is found to increase with increasing temperature, which suggests that the flexibility and conformation of n-alkane molecules confined in the aerogel play a crucial role; high-entropy (disordered) alkane configurations lead to the creation of numerous cavities which make it possible to solubilize a larger number of H-2 molecules. This departs from adsorption-driven solubility effects for which the number of solubilized molecules decreases with increasing temperature. For a given temperature and pressure, it is found that the number of solubilized H-2 molecules per unit volume increases with decreasing alkane chain length. Such an effect, which is observed for both the bulk alkanes and the alkanes confined in the silica aerogel, can be rationalized by considering the number density of CHx (x = 2 or 3) groups; for a given temperature, the latter number density decreases with decreasing alkane chain length so that the free volume available to solubilize H-2 molecules increases