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At least 451 records · Page 25

Amine-appended metal-organic frameworks exhibiting a new adsorption mechanism for carbon dioxide separations

An adsorption material is disclosed that comprises a metal-organic framework and a plurality of ligands. The metal-organic framework comprising a plurality of metal ions. Each respective ligand in the plurality of ligands is amine appended to a respective metal ion in the plurality of metal ions of the metal-organic framework. Each respective ligand in the plurality of ligands comprises a substituted 1,3-propanediamine. The adsorbent has a CO 2 adsorption capacity of greater than 2.50 mmol/g at 150 mbar CO 2 at 40° C. Moreover, the adsorbent is configured to regenerate at less than 120° C. An example ligand is diamine 2,2-dimethyl-1,3-propanediamine. An example of the metal-organic framework is Mg 2 (dobpdc), where dobpdc 4− is 4,4′-dioxidobiphenyl-3,3′-dicarboxylate. Example applications for the adsorption material are removal of carbon dioxide from flue gas and biogasses.

Long, Jeffrey R.↗

Multi-functionalized basic immobilized amine sorbents for removal of metal contaminants from wastewater

This disclosure provides polyamine sorbent compositions for the separation of metals from aqueous solutions. The polyamine sorbent compositions comprise a silica support, an aminosilane bound to the silica support, an epoxysilane bound to the silica support, and a polyamine where the polyamine is chemically tethered onto a solid silica support through via the epoxysilane. The polyamine may be further stabilized within the bulk sorbent through hydrogen bonding interactions with the aminosilane. The sorbent compositions resist leaching by H 2 O in an aqueous stream containing heavy oxyanion-based (and other) metals and demonstrate stability over a pH range of 2-14. The sorbent compositions are useful for the separation of metals from aqueous solutions. The cationic heavy metals are captured by the co-existing amine groups (—NH 2 , —NH, —N) from the polymeric network while additional metal capture capacity is derived from the introduction of a secondary silane linker.

Gray, McMahan L.↗

Robust Immobilized Amine CO 2 Sorbent Pellets Utilizing a Poly(Chloroprene) Polymer Binder and Fly Ash Additive

Pelletization of ca. 50 wt % amine/silica carbon dioxide sorbents was achieved with the novel combination of fly ash (FA) as a strength additive and hydrophobic poly(chloroprene) (PC) as a binder. The PC content and overall synthesis procedure of these materials were optimized to produce pellets, labeled as FA/E100-S_(20/80)_12.2, with the highest ball-mill attrition resistance (<0.5 wt % by fines, 24 h) and maximum CO 2 capture capacity of 1.78 mmol CO 2 g -1 . The strength of the pellets was attributed to hydrogen-bonding of the relatively homogeneous PC network with the interlocked FA and BIAS particles (DRIFTS, SEM-EDS). The low degradation of 3–4 % in the pellet's CO 2 capture capacity under both dry TGA (7.5 h) and practical fixed-bed (6.5 h dry; 4.5 h humid,≈5 vol % H 2 O) CO 2 adsorption–desorption conditions highlights the pellet's excellent cyclic stability. These robust pellet characteristics make PC/FA/sorbent materials promising for commercial scale, point-source CO 2 capture.

01 COAL, LIGNITE, AND PEAT↗

Sodium doping of solution-processed amine-thiol based CIGS solar cells by thermal evaporation of NaCl

Poor crystallinity, high degree of porosity and rough surfaces are the main drawbacks of solution-processed CIGS absorbers resulting in lower power conversion efficiencies when compared to vacuum-based CIGS solar cells. Therefore, promoting absorber grain growth is key to further improve solution-based solar cell performance. The effect of alkali elements such as Na in CIGS absorbers is generally recognised to have beneficial effects not only on the absorber opto-electronic properties but also on the grain growth. In this work, thermal evaporation of a thin layer of NaCl prior to selenisation resulted in absorbers with significantly larger CIGS grains than previously seen with Na diffusing directly from the from soda-lime glass substrate. NaCl is non-toxic, abundant and readily available compound that has not been typically used as an evaporation source, but rather as an additive into CIGS precursor solution. The effect of Na on these solution-processed CIGS devices was primarily observed in the spectacular morphological changes leading to improved carrier collection and minority carrier lifetimes, but less on the absorber doping. Transmission electron microscopy (TEM) revealed voids forming around large CIGS grains upon NaCl addition and these had a negative effect on inter-grain carrier transport. Nonetheless, the resulting device performance doubled from 5% to 10% with addition of Na using this doping approach; however, a compromise between the optimum grain growth and optimum electronic properties had to be made. This study demonstrates a novel, simple and effective Na-doping strategy for CIGS absorbers and reveals the current limitations of the Na-doping in solution-processed atmospherically deposited cells.

14 SOLAR ENERGY↗

Effect of Microadding Amine Surfactant on Erosion-Corrosion Wear of Structural Steel in NPP

Corrosion processes, specifically, erosion-corrosion, are one of the causes of damage occurring in NPP equipment during operation. Measures are taken to prevent erosion-corrosion wear of thermal-power equipment and pipelines. One such measure is the development and adoption of water chemistry regimes that are capable of forming a protective fi lm on a metal surface. Octadecylamine is one such reagent. The results of laboratory tests and industrial experiments studying the effect of octadecylamine on the development of erosion-corrosion wear of NPP equipment are presented. The octadecylamine-hydrazine water chemistry regime at octadecylamine concentration 0.5 mg/dm{sup 3} reduces the rate of erosion-corrosion wear by about 15-fold. The positive effect of micro-additions of octadecylamine is confirmed by direct erosion-corrosion studies performed at the Kola NPP.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Identification of pyrrolo[3,2-c]pyridin-4-amine compounds as a new class of entry inhibitors against influenza viruses in vitro

Various influenza virus entry inhibitors are being developed as therapeutic antiviral agents in ongoing preparation for emerging influenza viruses, particularly those that may possess drug resistance to the current FDA-approved neuraminidase inhibitors. In this study, small molecules having the pyrrolopyridinamine (PPA), aminothiadiazole (ATD), dihydrofuropyridine carboxamide (HPC), or imidazopyridinamine (IPA) moiety were selected from a target-focused chemical library for their inhibitory activity against influenza A virus by high-throughput screening using the PR8GFP assay. Activity was evaluated by measuring changes the proportion of GFP-expressing cells as a reflection of influenza virus infection. Among them, PPA showed broad-spectrum activity against multiple influenza A viruses and influenza B virus. PPA was found to block the early stages of influenza virus infection using a time-of-addition assay. Using additional phenotypic assays that dissect the virus entry process, it appears that the antiviral activity of PPA against influenza virus can be attributed to interference of the post-fusion process: namely, virus uncoating and nuclear import of viral nucleoprotein complexes. Based on these results, PPA is an attractive chemical moiety that can be used to develop new antiviral drug candidates against influenza viruses. - Highlights: • Four chemical classes are identified from target-focused chemical library by HTS. • PPA inhibits the infection of various influenza A viruses and influenza B virus. • PPA is identified to inhibit the early stages of influenza virus infection. • PPA compound disrupts virus uncoating and nuclear import of viral ribonucleoprotein.

60 APPLIED LIFE SCIENCES↗

Synthesis, structure and photoluminescence properties of amine-templated open-framework bismuth sulfates

Two organically-templated bismuth sulfates of the compositions, [C{sub 6}N{sub 2}H{sub 14}] [Bi(SO{sub 4}){sub 2}(NO{sub 3})], (1) and [C{sub 4}N{sub 2}H{sub 12}]{sub 4}[Bi{sub 4}(SO{sub 4}){sub 10}(H{sub 2}O){sub 4}], (2), with open architecture have been synthesized and their structures determined by single crystal X-ray diffraction. 1 has a corrugated layered structure with 8-membered aperture wherein the SO{sub 4} tetrahedra and the BiO{sub 8} polyhedra join together to form (4, 4) net sheets of the metal centers while 2 has a three-dimensional structure possessing 8- and 12-membered channels. Both the compounds show good fluorescence properties exhibiting blue luminescence. Time-resolved fluorescence behavior of 1 and 2 shows mean fluorescence life time of 0.9 and 1.0 ns, respectively. - Graphical abstract: Two open-framework bismuth sulfates with the layered and three-dimensional structures have been synthesized and characterized. Both the compounds show good fluorescence properties exhibiting blue luminescence. Display Omitted - Highlights: • Two organically-templated bismuth sulfates with open architecture have been synthesized and characterized. • One has a corrugated layered structure while the other one has a three-dimensional structure possessing channels. • They are novel in that open-framework three-dimensional main group metal sulfates are first to be reported. • They show good fluorescence properties exhibiting blue luminescence.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Amine functionalized supported ionic liquid membranes (SILMs) for CO 2 /N 2 separation

Supported ionic liquid membranes (SILMs), containing aprotic N-heterocyclic anion ionic liquids (AHA ILs) in an inorganic inert support, exhibit CO 2 /N 2 permselectivity values as high as 640 at 35.0 °C and 0.03 bar CO 2 , which represents conditions similar to post-combustion carbon capture (PCCC) from a natural gas power plant. A Fickian model fit to the experimental data estimates CO 2 permeability at direct air capture (DAC) conditions of 10,400 barrer and a CO 2 /N 2 permselectivity of 4000 for the best performing IL, triethyl(octyl)phosphonium 4-bromopyrazolide ([P 2228 ][4-BrPyra]). The most important criterion for high selectivity is a large equilibrium constant for binding between the IL and CO 2 , which results in high CO 2 solubility. ILs with smaller molar volumes and with no fluoroalkyl chains enhance N 2 rejection. As a result, low viscosity and high IL molar density also enhance CO 2 /N 2 permselectivity and CO 2 permeance.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Kinetics, Products, and Brown Carbon Formation by Aqueous-Phase Reactions of Glycolaldehyde with Atmospheric Amines and Ammonium Sulfate

Glycolaldehyde (GAld) is a C 2 water-soluble aldehyde produced during the atmospheric oxidation of isoprene and many other species and is commonly found in cloudwater. Previous work has established that glycolaldehyde evaporates more readily from drying aerosol droplets containing ammonium sulfate (AS) than does glyoxal, methylglyoxal, or hydroxyacetone, which implies that it does not oligomerize as quickly as these other species. Here, we report NMR measurements of glycolaldehyde’s aqueous-phase reactions with AS, methylamine, and glycine. Reaction rate constants are smaller than those of respective glyoxal and methylglyoxal reactions in the pH range of 3–6. In follow-up cloud chamber experiments, deliquesced glycine and AS seed particles were found to take up glycolaldehyde and methylamine and form brown carbon. At very high relative humidity, these changes were more than 2 orders of magnitude faster than predicted by our bulk liquid NMR kinetics measurements, suggesting that reactions involving surface-active species at crowded air–water interfaces may play an important role. The high-resolution liquid chromatography–electrospray ionization–mass spectrometric analysis of filter extracts of unprocessed AS + GAld seed particles identified sugar-like C 6 and C 12 GAld oligomers, including proposed product 3-deoxyglucosone, with and without modification by reactions with ammonia to diimine and imidazole forms. Chamber exposure to methylamine gas, cloud processing, and simulated sunlight increased the incorporation of both ammonia and methylamine into oligomers. Many C 4 –C 16 imidazole derivatives were detected in an extract of chamber-exposed aerosol along with a predominance of N-derivatized C 6 and C 12 glycolaldehyde oligomers, suggesting that GAld is capable of forming brown carbon SOA.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Electrically Conductive Amine Functionalized Reduced Graphite Oxide Foam for CO 2 Removal from the Air

Rapid regeneration of CO 2 adsorbents is critical to improving the productivity of direct air capture (DAC) systems. In this study, we codesigned a material to have appropriate electrical conductivity and CO 2 adsorption properties to enable efficient CO 2 capture from air. Specifically, we present a poly(ethylenimine) (PEI)-impregnated thermally annealed graphite oxide (TAGO900) foam adsorbent tailored for vacuum-assisted electrically driven thermal swing adsorption (V-ETSA). This structured adsorbent leverages the high electrical conductivity of the reduced graphite oxide framework to enable fast and direct heating of the adsorbent material by electrical resistance heating (Joule heating). An optimal sample, 40 wt % PEI (molecular weight 25k) impregnated TAGO900, shows the best balance between adsorption capacity (1.54 mmol g –1 ) and adsorption rates (0.016 mmol g –1 min –1 ) using fixed bed breakthrough experiments at 25 °C and 70% RH using 50 sccm 400 ppm of CO 2 /N 2 flow. Compared to conventional temperature vacuum swing adsorption (TVSA), the V-ETSA approach achieves substantially faster CO 2 desorption, achieving average desorption rates (including cooling time) of 0.09 mmol g –1 min –1 ─approximately 2.5 times faster than TVSA under similar operating conditions. The maximum desorption rate reaches 0.23 mmol/g/min during the desorption stage. These results underscore the importance of the direct heating strategy, such as Joule heating, for fast and highly productive vacuum swing adsorption in DAC systems.

amines↗