The development of nanostructured composites made of metal−organic frameworks (MOFs) and graphene-based components, including exfoliated nanoplates of graphene oxide (GO) or reduced (rGO) graphene oxide, is an area of great interest in gas storage and separation. To improve the industrial viability, it is commonly demanded to build these nanocomposites with the shape of compact units, such as monoliths, foams, pellets, or films. Methods to generate those 3D nanocomposites involving rGO are abundant; however, they become scarce when GO is the desired support due to the difficulty in maintaining the carbon matrix oxidized during the structuration process. In this work, a methodology based on the use of supercritical CO 2 (scCO 2 ) is described for the synthesis of nanocomposites involving a discontinuous MOF phase, e.g. nanoparticles (NPs) of HKUST-1, decorating the surface of a continuous GO matrix, with surface oxygen groups favoring MOF attachment. The use of this new supercritical methodology allows the nanostructuration of the composite in the form of 3D aerogels while avoiding the reduction of GO. Enhanced values of textural properties, determined by low-temperature N 2 adsorption−desorption, were observed for the nanocomposites in comparison to the values calculated for similar physical mixtures, highlighting an increase of 40−45% in the value of the surface area for samples with a high percentage of HKUST-1. Moreover, the composite aerogels, displaying a type II isotherm, outperform pristine HKUST-1 in regard to the CH 4 practical working capacity at high pressure. Particularly, a composite exhibiting more than 2-fold the working capacity of net HKUST-1 NPs was obtained. Columns involving the composite aerogel as the stationary phase were used to study the separation of N 2 /CO 2 and CH 4 /CO 2 gas mixtures. The results showed a high selectivity of the nanostructured HKUST-1@GO composites for CO 2 , with breakthrough times of ca. 20 min g −1 and stable cyclic operations.

Model-Based Systems Engineering (MBSE) is an emerging engineering discipline whose driving motivation is to provide support throughout the entire system life cycle. MBSE not only addresses the engineering of software systems but also their interplay with physical systems. Quite frequently, successful systems need to be customized to cater for the concrete and specic needs of customers, end-users, and other stakeholders. To eectively meet this demand, it is vital to have in place mechanisms to cope with the variability, the capacity to change, that such customization requires. In this paper we describe our experience in modeling variability using SysML, a leading MBSE language, for developing a product line of wind turbine systems used for the generation of electricity.

Supporting Information: EDS mapping of Fe 3 O 4 @GO (S1), XPS calculations for the surface composition of the samples.

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The reaction of [Co 2 (H 2 O)(TFMBz) 4 (py) 4 ] (1) (TFMBz: 3,5bis(trifluoromethyl)benzoate; py: pyridine) with 4,4′-bipyridine (bpy) in different solvents yields four coordination polymers with unlikely structures but with the same stoichiometry. Three of them contain similar ladder chains consisting of binuclear nodes "Co 2 (TFMBz) 4 ", in which two of the TFMBz ligands show bidentate bridge coordination, double linked to each adjacent node by bpy but packed in different fashions. The different packing affects the compound porosity; thus, [Co 2 (TFMBz) 4 (bpy) 2 ] n (2), precipitated using low-polarity solvents such as supercritical CO 2 (scCO 2 ), n-butyl acetate, or heptane and also in acetonitrile, is microporous, with a surface area of 330 m 2 g −1 , showing the N 2 adsorption/desorption isotherm at 77 K with a gate-opening effect at low relative pressures (P/P 0 = 0.05). The isomer [Co 2 (TFMBz) 4 (bpy) 2 ] n (3), synthesized in ethoxyethanol, presents a surface area of 230 m 2 g −1 . A third chain packing isomer, [Co 2 (TFMBz) 4 (bpy) 2 ] n (4), is obtained in acetone and has only non-interconnected voids. Finally, precursor 1 is combined with bpy in a highly polar solvent such as water to give [Co(TFMBz) 2 (bpy)] n (5). In this isomer, all the carboxylate units act as bidentate bridging ligands, generating chains that are interlinked by bpy, leading to a 2D network, which after packing yields a non-porous structure. The resolution of structures 2−5 is only possible with the recently developed 3D electron diffraction method based on the collection of diffraction patterns on sub-micron-sized single crystals. The variation of magnetic susceptibility as a function of temperature is also measured. Overall, our work provides insightful information on the complex landscape of metal−organic framework solids that are formed by crystallization using different solvent media.