Tag Archives: 23Na-NMR

NaAlH4 confined in Ordered Mesoporous Carbon

hydrogen_energyNaAlH4 confined in Ordered Mesoporous Carbon

Bonatto, C.; Lindemann, I.; Nolis, P.; KieBling, A.; Baró, M. D.; Klose, M.; Giebler, L.; Rellinghaus, B.; Eckert, J.; Schultz, L.; Gutfleisch, O.

In this paper we performed a comprehensive investigation of the structural and sorption properties of a 40 wt. % NaAlH4 confined in a ordered mesoporous carbon (OMC, i.e. CMK-3) by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), 23Na{1H} and 27Al{1H} solid-state magic angle spinning-nuclear magnetic resonance (MAS-NMR).

This study evidences a remarkable improvement of the sorption kinetics of NaAlH4 due to its existence in nanometer size within the OMC. The pressure composition isotherm (PCI) analysis (for the re-absorption step) of the nanoconfined NaAlH4 would suggest an alteration of its equilibrium thermodynamic properties.

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Sodium mobility on dry-cured ham studied by T2 relaxation times

“High pressure processing of dry-cured ham: Ultrastructural and molecular changes affecting sodium and water dynamics” Pierre A. Picoueta, Xavier Sala, Núria Garcia-Gila, Pau Nolis, Maddalena Colleo, Teodor Parella, Jacint Arnau. Innovative Food Science & Emerging Technologies. Available online 4 August 2012. DOI: 10.1016/j.ifset.2012.07.008

High pressure processing (HPP) has become a popular method to reduce bacterial load on dry-cured ham. However, HPP processed hams tend to present higher saltiness than non-processed ones. In this study was evaluated the effect of processing Biceps femoris samples of 9 dry-cured hams aged for 15 months at a pressure of 0.1, 300, 600 and 900 MPa. 23Na-Nuclear Magnetic Resonance (NMR) relaxation values were used to determine the mobility of sodium. Continue reading Sodium mobility on dry-cured ham studied by T2 relaxation times

Experimental evidence of Na2[B12H12] and Na formation in the desorption pathway of the 2NaBH4 + MgH2 system

“Experimental evidence of Na2[B12H12] and Na formation in the desorption pathway of the 2NaBH4+ MgH2 system”, by Sebastiano Garroni, Chiara Milanese, Daphiny Pottmaier, Gabriele Mulas, Pau Nolis, Alessandro Girella, Riccarda Caputo, David Olid-Britos, Francesc Teixidor, Marcello Baricco, Amedeo Marini, Santiago Suriñach, and Maria Dolores Baró. The Journal of Physical Chemistry C, Volume 115, Pages 16664-16671, July 2011. DOI: 10.1021/jp202341j

In the present work we report the desorption pathway of the 2NaBH4 + MgH2 system. Ex-situ X-ray powder diffraction (XRPD) and solid state magic angle spinning (MAS) nuclear magnetic resonance (NMR) measurements have been performed on samples heat-treated up to 450°C for different times. Ex-situ X-ray powder diffraction experiments conducted on fully desorbed samples allowed to identify nanocrystalline MgB2 and metallic Na as dehydrogenation products. Continue reading Experimental evidence of Na2[B12H12] and Na formation in the desorption pathway of the 2NaBH4 + MgH2 system