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Liquid‐like nanoparticle organic hybrid materials (NOHMs) consisting of a silica core with ionically grafted branched polyethyleneimine chains (referred to as NIPEI) are encapsulated within submicron‐scale polyacrylonitrile (PAN)/polymer‐derived‐ceramic electrospun fibers. The addition of a room‐temperature curable, liquid‐phase organopolysilazane (OPSZ) ceramic precursor to the PAN/NOHM solution enhances the internal dispersion of NOHMs and forms a thin ceramic sheath layer on the fiber exterior, shielding the hydrophilic NIPEI to produce near‐superhydrophobic non‐woven fiber mats with contact angles exceeding 140°. 60:40 loadings of NOHMs to PAN/OPSZ can be reliably achieved with low OPSZ percentages required, and up to 4:1 NOHM:polymer loadings are possible before losing hydrophobicity. These fibers demonstrate up to ≈2 mmol CO2 g−1 fiber capture capacities in a pure CO2 atmosphere through the nonwoven fibrous networks and the permeability of the OPSZ shell. The hybrid fibers additionally show enhanced capture kinetics under pure CO2 and 400 ppm CO2 conditions, indicating their promising application as a direct air capture platform. [ABSTRACT FROM AUTHOR]

Electrospinning (ES) of ceramic fibers has mostly remained in the research level, which can be because of the hard process and parameters controlling the low rate of production. The yield of fiber production by solution blow spinning (SBS) is exciting but the production process is unstable due to the reverse flow phenomenon. In this paper, we prepared high-performance ceramic fibers by gas-assisted electrospinning (GES), which combined the advantages of ES and SBS. Also, comprehensive numerical and experimental analysis for nanofibers produced using GES are provided. The gas flow characteristics through different parameters' nozzle were investigated numerically using computational fluid dynamics and experimentally in a custom-built gas-assisted electrospinning setup to produce SiO2 nanofibers.

• Gas-assisted electrospinning of SAN solution with up to 270 μL.min−1 injection rate. • Nanofibrous membrane with unique features for treating dyeing effluent using DCMD. • An affordable, dual-layer membrane based on a commercial hydrophilic nonwoven. • Remarkable performance for COD (98%), color (99.9%), and TDS (99.5%) removal. A robust, nanofibrous membrane with dual-layer composite structure and remarkable features has been developed in this work. The new membrane is based on the affordable styrene-acrylonitrile (SAN) polymer and a commercial hydrophilic nonwoven for the support layer. This can help to step forward the industrialization of the direct contact membrane distillation (DCMD) process for treating the hot dyeing effluent in the textile industry. The modified electrospinning with a gas-jet surrounding the Taylor cone was used for fabricating the membrane samples. Using the gas-assisted electrospinning, a nanofibrous nonwoven structure embedded with micro-cups and micro-spheres can be achieved in a one-step, gas-assisted electrospinning. The hydrophilic substrate was used for enhancing the permeate flux of the resultant composite membrane. The fabricated membrane showed remarkable features in comparison with a commercial polytetrafluoroethylene (PTFE) membrane, including high surface hydrophobicity (≥148°), higher porosity (≥81%), and smaller tortuosity factor (1.71). The unique properties of the membrane with the best performance provided a promising permeate flux (28.31 kg.m−2.h−1) and contaminant rejection (R COD : 98.15%) compared to the commercial membrane (flux: 18.50 kg.m−2.h−1 and R COD : 97.10%), without considerable pore wetting. However, the new membrane possessed lower liquid entry pressure (LEP) owing to its higher porosity, larger maximum pore size (0.76 μm), and thinner structure (150 μm). Results indicated that the decline in the permeate flux was mainly caused by the cake layer formation on the surface of the membrane rather than the partial pore wetting during the long-term operation for 48 h. Therefore, the newly developed nanofibrous SAN membrane with hydrophobic/hydrophilic composite structure is a promising, robust candidate for DCMD application in the textile wastewater treatment. [ABSTRACT FROM AUTHOR]

Most commercially available hydrogels have a low surface to volume ratio due to the spherical or pseudo-spherical geometry, which highly affects the corresponding swelling properties of the hydrogels. In this study, a nanofibrous superabsorbent were prepared using the gas-assisted electrospinning of Poly(acrylic acid) (PAA). The morphology of the nanofibrous hydrogel and its effect on the swelling performance were investigated. For this purpose, different concentrations of PAA solutions, operating conditions for the gas-assisted electrospinning technique, as well as cross-linking agent (1,4-butanediol diglycidyl ether) were studied. Moreover, sodium hydroxide (NaOH) was used to neutralize the PAA solutions in different contents. Fourier-transform infrared spectroscopy was used to investigate the hydrogel structure and the chemical cross-linking reaction. The scanning electron microscopy (SEM) was used to investigate the fibers morphology. SEM results confirmed the nanofiber formation using the gas-assisted electrospinning in this work. Free absorption, absorption under load, and the dynamic mechanical properties behavior of the specimens were investigated, demonstrating that the specimen prepared using 9 wt% PAA, 30% neutralized by NaOH solution, electrospun at 20 μL/min, and cross-linked by 1,4-butanediol diglycidyl ether had the highest swelling ratio, up to 90,000% and 30,000% for distillated water and standard NaCl solution, respectively. [ABSTRACT FROM AUTHOR]

Direct Air Capture Materials An electrospun fiber of an amine‐based NOHMs encapsulated ceramic sheath. In article number 2301649, Yong Lak Joo, Ah‐Hyung A. Park, Michelle K. Kidder, and co‐workers show that novel hybrid fiber can selectively capture carbon dioxide while allowing rejection of water, to help reduce the energy penalty upon regeneration. The fiber is envisioned to have application in direct air capture in filter materials used in systems that move large quantity of air, such as HVAC. [ABSTRACT FROM AUTHOR]