The first sorbent with high CO2 selectivity and poor water affinity addresses need for trace CO2 remediation in confined spaces.

Physical adsorption of gas molecules in microporous materials is an exothermic process, with desorption entropy driving a decrease in uptake with temperature. Enhanced gas sorption with increasing temperature is rare in porous materials and is indicative of sorbate initiated structural change. Here, sorption of C2H6, C3H6, and C3H8 in a flexible microporous metal–organic framework (MOF) {Cu­(FPBDC)]·DMF} n (NKU-FlexMOF-1) (H2FPBDC = 5-(5-fluoropyridin-3-yl)-1,3-benzenedicarboxylic acid) that increases with rising temperature over a practically useful temperature and pressure range is reported along with other small molecule and hydrocarbon sorption isotherms. Single X-ray diffraction studies, temperature-dependent gas sorption isotherms, in situ and variable temperature powder X-ray diffraction experiments, and electronic structure calculations were performed to characterize the conformation-dependent sorption behavior in NKU-FlexMOF-1. In total, the data supports that the atypical sorption behavior is a result of loading-dependent structural changes in the flexible framework of NKU-FlexMOF-1 induced by sorbate-specific guest–framework interactions. The sorbates cause subtle adaptations of the framework distinct to each sorbate providing an induced-fit separation mechanism to resolve chemically similar hydrocarbons through highly specific sorbate–sorbent interactions. The relevant intermolecular contacts are shown to be predominantly repulsion and dispersion interactions. NKU-FlexMOF-1 is also found to be stable in aqueous solutions including toleration of pH changes. These experiments demonstrate the potential of this flexible microporous MOF for cost and energy efficient industrial hydrocarbon separation and purification processes. The efficacy for the separation of C3H6/C3H8 mixtures is explicitly demonstrated using NKU-FlexMOF-1a (i.e., activated NKU-FlexMOF-1) for a particular useful temperature range.

The etiology of autoimmune liver disease is poorly understood. BALB/c mice deficient in the immunoregulatory cytokine TGF-β1 spontaneously develop necroinflammatory liver disease, but the immune basis for the development of this pathology has not been demonstrated. Here, we show that BALB/c-TGF-β1−/− mice exhibit abnormal expansion in hepatic mononuclear cells (MNCs) compared with wild-type littermate control mice, particularly in the T cell and macrophage lineages. To test whether lymphocytes of the adaptive immune system are required for the spontaneous development of necroinflammatory liver disease, BALB/c-TGF-β1−/− mice were rendered deficient in B and T cells by crossing them with BALB/c-recombinase-activating gene 1−/− mice. BALB/c-TGF-β1−/−/recombinase-activating gene 1−/− double-knockout mice showed extended survival and did not develop necroinflammatory liver disease. The cytolytic activity of BALB/c-TGF-β1−/− hepatic lymphocytes was assessed using an in vitro CTL assay. CTL activity was much higher in BALB/c-TGF-β1−/− hepatic MNCs compared with littermate control hepatic MNCs and was particularly pronounced in the CD4+ T cell subset. Experimental depletion of CD4+ T cells in young BALB/c-TGF-β1−/− mice prevented the subsequent development of necroinflammatory liver disease, indicating that CD4+ T cells are essential for disease pathogenesis in vivo. These data definitively establish an immune-mediated etiology for necroinflammatory liver disease in BALB/c-TGF-β1−/− mice and demonstrate the importance of CD4+ T cells in disease pathogenesis in vivo. Furthermore, TGF-β1 has a critical role in homeostatic regulation of the hepatic immune system, inhibiting the development or expansion of hepatic cytolytic CD4+ T cells.

Acetylene (C 2 H 2 )c apturei sastep in an umber of industrial processes, but it comes with ah igh-energy footprint. Although physisorbents have the potential to reduce this energy footprint, they are handicappedb y generally poor selectivity versusother relevant gases, such as CO 2 and C 2 H 4 .I nt he case of CO 2 ,t he respective physicochemical properties are so similar that traditional physisorbents, such as zeolites, silica, anda ctivated carbons cannot differentiate well between CO 2 and C 2 H 2 .H erein, we report that af amily of three isostructural, ultramicroporous (< 7 )d iamondoidm etal-organic frameworks, [Cu(TMBP)X] (TMBP = 3,3',5,5'-tetramethyl-4,4'-bipyrazole), TCuX (X = Cl, Br,I ), offer new benchmark C 2 H 2 /CO 2 separation selectivity at ambient temperature and pressure.W e attribute this performance to an ew type of strong binding site for C 2 H 2 .S pecifically,h alogen···HC interactions coupledw ith othern oncovalent in at ight binding site is C 2 H 2 specific versus CO 2 .T he binding site is distinct from those found in previous benchmark sorbents, which are based on open metal sites or electrostatic interactionse nabled by inorganic fluoro or oxo anions.That C 2 H 2 poses an immediate fire and explosive hazard at > 2.5 %c oncentrations and features the widest knownf lammability range, [1] 2.5-81 %, underscores the need to develop energy-efficient C 2 H 2 -capture sorbent materials. [2] Further,i ts high reactivity can lead to undesirable chemicalr eactions duringi ndustrial processes, for example, traces of C 2 H 2 can poisonc atalystsb yf orming metal acetylides duringe thylene polymerization, leading to explosions. [3] Removal of C 2 H 2 as a trace contaminant is also important in the productiono fa crylic/vinyl derivatives and acetylenic alcohols. [4] With respect to bulk usage,C 2 H 2 is the most common gas used to fuel cutting torches. C 2 H 2 recovered in high purity can serve as af uel or buildingblock in polymer synthesis for example, polyvinyl chloride, PVC and polyvinylidene fluoride,PVDF. [4] In C 2 H 2 manufacturedb yp artial combustion (oxidative coupling)o fmethane [5] or thermal cracking of hydrocarbons, CO 2 is generated as ab y-product. [6] To enable C 2 H 2 capturef rom C 2 H 2 /CO 2 mixtures, three current methods were employed: 1) bulk extraction by organic solvents, for example, N,N-dimethylformamide, and acetone; [7] b) partial hydrogenation of C 2 H 2 to ethylene, C 2 H 4 using expensive Ag 0 /other noble-metalc atalysts; [8] and c) cryogenic distillation. [9] All three approaches are costly and energy intensive. Althoughp hysisorbentso ffer potentialf or reducing the energyf ootprint of C 2 H 2 capture, zeolites, silica, and activated carbonsc annot effectively separate C 2 H 2 from CO 2[10] because of their similarp hysicochemical properties (size:C 2 H 2 = 3.32 3.34 5.7 3 ;C O 2 = 3.18 3.33 5.36 3 ;k inetic diameter = 3.3 for both;b oilingp oint:C 2 H 2 = 189.3 K, CO 2 = 194.7 K). [11] In this context,a ne merging class of physisorbents, namely, metal-organic m...

Grand canonical Monte Carlo (GCMC) simulations of gas sorption were performed in Cu-TDPAH, also known as rht-MOF-9, hereafter [1], a metal-organic framework (MOF) with rht topology consisting of Cu ions coordinated to 2,5,8-tris(3,5-dicarboxyphenylamino)-1,3,4,6,7,9,9b-heptaazaphenalene (TDPAH) ligands. This MOF is notable for the presence of open-metal copper sites and high nitrogen content on the linkers. [1] Exhibits one of the highest experimental H uptakes at 77 K/1 atm within the extant rht-MOF family (ca. 2.72 wt%) and also has strong affinity for CO (5.83 mmol g at 298 K/1 atm). Our simulations, which include explicit many-body polarization interactions, accurately modeled macroscopic thermodynamic properties (e.g., sorption isotherms and isosteric heats of adsorption (Q)) as well as the binding sites for H, CO, CH, CH, CH, and CH in the MOF. Four different binding sites were observed through analysis of the radial distribution function (g(r)) about the two chemically distinct Cu ions, simulated annealing calculations, and examination of the three-dimensional histogram showing the sites of occupancy: (1) at the Cu ion facing toward the center of the linker (CuL), (2) at the Cu ion facing away from the center of linker (CuC), (3) nestled between three [Cu(OCR)] units in the corner of the truncated tetrahedral (T-T) cage and (4) straddling the copper nuclei parallel to the axis of the Cu-Cu bond within the T-T cage. The low-loading (initial) binding site in the MOF is highly sensitive to the partial charges of the Cu ions that were used for parametrization. It was discovered that most sorbates prefer to sorb onto or near the Cu ions that exhibit the greater partial positive charge (i.e., at site 1). The simulated H and CO sorption results obtained using a polarizable potential for the respective sorbates are in good agreement with the corresponding experimental data, especially near ambient pressure. Simulations of gas sorption were also performed in [1] using nonpolarizable potentials for the individual sorbates; these include potentials from the TraPPE force field for most sorbates.