Engineering Nanoporous Polyaminal Networks for Superior SO2 Capture and Selectivity.

Designing adsorbent materials with high SO2 adsorption capacities and selectivity remains a significant challenge in flue gas desulfurization. This work focuses on developing two nitrogen-rich nanoporous polyaminal networks (NPANs), which demonstrate promising capabilities for SO2 adsorption and separation. Two nitrogen-rich nanoporous polyaminal networks, NPAN-5 and NPAN-6, were synthesized via a one-pot method using thiophene-2,5-dicarbaldehyde and furan-2,5-dicarbaldehyde with 1,4-bis(2,4-diamino-1,3,5-triazine)-benzene, respectively. The Brunauer-Emmett-Teller (BET) specific surface areas of NPANs range from 838 to 956 m2·g-1. At 298 K and pressures of 0.1 and 1.0 bar, NPAN-5, featuring thiophene units, demonstrates a SO2 adsorption uptake of 5.14 and 9.63 mmol·g-1, respectively, surpassing many previously reported materials. Furthermore, at room temperature, NPAN-6, containing furan moieties, exhibits unprecedented selectivity for SO2 over CO2 and N2, with ratios reaching up to 78 and 9321, respectively. Dynamic breakthrough experiments reveal that NPANs effectively separate SO2 from a ternary gas mixture comprising SO2, CO2, and N2 at concentrations of 0.2, 10, and 89.8%, respectively. Notably, NPAN-6 achieves a prolonged SO2 retention time of 218 min·g-1 and a saturation adsorption uptake of 0.42 mmol·g-1. The remarkable SO2 adsorption capacities and selectivities demonstrated by these nitrogen-rich nanoporous polyaminal networks underscore their potential to revolutionize industrial flue gas desulfurization.

Room-temperature synthesis of a fluorine-functionalized nanoporous organic polymer for efficient SF6 separation.

Addressing the environmental impact of SF6, we synthesized a fluorine-functionalized triphenylamine-based nanoporous organic polymer, ANOP-8, at room temperature using N,N,N',N'-tetraphenylbenzidine and 2,3,4,5,6-pentafluorobenzaldehyde. ANOP-8, which incorporates 14.86% fluorine, has a BET surface area of 694 m2 g-1 and a robust C-C structure. It achieves SF6/N2 selectivities of 65 and 51 at 298 K and 1 bar through ideal adsorbed and breakthrough experiments, respectively. Molecular simulations have revealed the adsorption mechanisms, underscoring the potential of fluorinated polymers in developing future adsorbents for toxic gases.

Highly Selective SO2 Capture by Triazine-Functionalized Triphenylamine-Based Nanoporous Organic Polymers.

The emissions of sulfur dioxide (SO2) from combustion exhaust gases pose significant risks to public health and the environment due to their harmful effects. Therefore, the development of highly efficient adsorbent polymers capable of capturing SO2 with high capacity and selectivity has emerged as a critical challenge in recent years. However, existing polymers often exhibit poor SO2/CO2 and SO2/N2 selectivity. Herein, we report two triazine-functionalized triphenylamine-based nanoporous organic polymers (ANOP-6 and ANOP-7) that demonstrate both good SO2 uptake and high SO2/CO2 and SO2/N2 selectivity. These polymers were synthesized through cost-effective Friedel-Crafts reactions using cyanuric chloride, 3,6-diphenylaminecarbazole, and 2,2',7,7'-tetrakis(diphenylamino)-9,9'-spirobifluorene. The resultant ANOPs are composed of triazine and triphenylamine units and feature an ultramicroporous structure. Remarkably, ANOPs exhibit impressive adsorption capacities for SO2, with uptakes of approximately 3.31-3.72 mmol·g-1 at 0.1 bar, increasing to 9.52-9.94 mmol·g-1 at 1 bar. The static adsorption isotherms effectively illustrate the ability of ANOPs to separate SO2 from SO2/CO2 and SO2/N2 mixtures. At 298 K and 1 bar, ANOP-6 shows outstanding selectivity toward SO2/CO2 (248) and SO2/N2 (13146), surpassing all previously reported triazine-based nanoporous organic polymers. Additionally, dynamic breakthrough tests demonstrate the superior separation properties of ANOPs for SO2 from an SO2/CO2/N2 mixture. ANOPs exhibit a breakthrough time of 73.1 min·g-1 and a saturated SO2 capacity of 0.53 mmol·g-1. These results highlight the exceptional adsorption properties of ANOPs for SO2, indicating their promising potential for the highly efficient capture of SO2 from flue gas.

Regulation of blood-brain barrier integrity by Dmp1-expressing astrocytes through mitochondrial transfer.

The blood-brain barrier (BBB) acts as the crucial physical filtration structure in the central nervous system. Here, we investigate the role of a specific subset of astrocytes in the regulation of BBB integrity. We showed that Dmp1-expressing astrocytes transfer mitochondria to endothelial cells via their endfeet for maintaining BBB integrity. Deletion of the Mitofusin 2 (Mfn2) gene in Dmp1-expressing astrocytes inhibited the mitochondrial transfer and caused BBB leakage. In addition, the decrease of MFN2 in astrocytes contributes to the age-associated reduction of mitochondrial transfer efficiency and thus compromises the integrity of BBB. Together, we describe a mechanism in which astrocytes regulate BBB integrity through mitochondrial transfer. Our findings provide innnovative insights into the cellular framework that underpins the progressive breakdown of BBB associated with aging and disease.

Osteocyte mitochondria regulate angiogenesis of transcortical vessels.

Transcortical vessels (TCVs) provide effective communication between bone marrow vascular system and external circulation. Although osteocytes are in close contact with them, it is not clear whether osteocytes regulate the homeostasis of TCVs. Here, we show that osteocytes maintain the normal network of TCVs by transferring mitochondria to the endothelial cells of TCV. Partial ablation of osteocytes causes TCV regression. Inhibition of mitochondrial transfer by conditional knockout of Rhot1 in osteocytes also leads to regression of the TCV network. By contrast, acquisition of osteocyte mitochondria by endothelial cells efficiently restores endothelial dysfunction. Administration of osteocyte mitochondria resultes in acceleration of the angiogenesis and healing of the cortical bone defect. Our results provide new insights into osteocyte-TCV interactions and inspire the potential application of mitochondrial therapy for bone-related diseases.

A nanoporous organic polymer using 1, 3-dibromoadamantane as a crosslinker for adsorption/separation of benzene and cyclohexane.

The development of nanoporous organic polymers with cycloaliphatic components for effective benzene (Bz) and cyclohexane (Cy) adsorption/separation poses a significant challenge. This work focuses on synthesizing NOP-Ad-1, a nanoporous organic polymer derived from a Friedel-Crafts reaction between cycloaliphatic 1,3-dibromadantane and aromatic hexaphenylbenzene. At 298 K and P/P0 = 0.95, NOP-Ad-1 can uptake 989 mg g-1 benzene and 441 mg g-1 cyclohexane. Moreover, as the benzene vapor ratio increased from 20% to 80%, the Bz/Cy selectivity of NOP-Ad-1 gradually decreased from 1.75 to 1.24. These findings highlight the potential application of NOP-Ad-1 in the adsorption/separation of Bz/Cy mixtures.