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The use of carbonized polymers has ushered in a new class of materials with profound implications for the gas separation industry. This study explored the transformation of polyvinylidene fluoride (PVDF) into microporous carbon structures coated onto ceramic substrates, enabling in situ growth of carbon molecular sieve (CMS) materials over hollow fibers. This material featured more robust CMS membranes than alumina and demonstrated exceptional capability in vital gas separations, particularly for CO 2 /CH 4. This novel approach increased the selectivity for gases and exhibited remarkable aging resilience, so the material is a compelling candidate for high-performance gas separations. Furthermore, after 31 days, the weathered carbon dioxide membrane exhibited a slight permeability drift from 234.88 barrers to 195.35 barrers, while the CO 2 /CH 4 ratio increased from 24.21 to 57.14, surpassing the Robeson 2008 upper bound. The PVDF-derived supported hollow fiber carbon membranes provide a blueprint for designing membranes for carbon capture. With the high packing density of the hollow fiber membrane and improved mechanical strength of the supported carbon membrane, this approach overcame the high fabrication costs and brittleness of other carbon membranes. In addition, the entire process for preparation of the PVDF carbon films is easily scaled up and has great potential for future practical application. [Display omitted] • Intermediate layer free growth of uniform CMS over the ceramic hollow membrane. • Controlled PVDF concentration with homogenous pore hollow support provides defect-free membrane. • PVDF originated CMS prescribes higher molecular precision for CO 2 capture. • PVDF based CMS enhances the resilience towards aging for the carbon separation. • Robust CMS membranes can advertise enhances carbon capture for a month duration. [ABSTRACT FROM AUTHOR]

We report a vapor-phase deposition of poly( p -xylylene) (parylene) membranes for gas separations. Three parylene membranes, poly[(2-chloro- p -xylylene)] (parylene C), poly[(4-amino- p -xylylene)- co -( p -xylylene)] (parylene A), and poly[(2-carboxylic acid N-hydroxysuccinimide ester)- co -( p -xylylene)] (parylene NHS ester), were evaluated. These membranes were deposited on a support of porous poly(vinylidene fluoride) with a dense layer of poly(vinyl alcohol) cast on its top surface. The as-synthesized parylene membranes were characterized by scanning electron microscopy, FT-IR spectroscopy, and the measurements of water contact angle. Single-gas permeation with hydrogen, nitrogen, methane, and carbon dioxide was performed on the parylene membranes for assessing their molecular transport properties. These parylene membranes showed gas permeability of up to hundreds of barrer. To further enhance the gas separation performance of the parylene membranes, polyethylenimine (PEI) was used for modifying the surface of the membranes composed of parylene NHS ester. [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) are highly reactive, making them useful for environmental and health applications. Traditionally, photocatalysts and piezocatalysts have been used to generate ROS, but their utilization is limited by various environmental and physical constraints. This study introduces metal-organic frameworks (MOFs) as modern thermocatalysts efficiently producing hydrogen peroxide (H 2 O 2 ) from small temperature differences. Temperature fluctuations, abundant in daily life, offer tremendous potential for practical thermocatalytic applications. As proof of concept, MOF materials coated onto carbon fiber fabric (MOF@CFF) created a thermocatalytic antibacterial filter. The study compared three different MOFs (CuBDC, MOF-303, and ZIF-8) with bismuth telluride (Bi 2 Te 3 ), a known thermocatalytic material. ZIF-8 demonstrated superior H 2 O 2 generation under low-temperature differences, achieving 96% antibacterial activity through temperature variation cycles. This work advances potential in thermoelectric applications of MOFs, enabling real-time purification and disinfection through H 2 O 2 generation. The findings open interdisciplinary avenues for leveraging thermoelectric effects in catalysis and various technologies.

Mixed-matrix membranes (MMMs) have been reported to have considerable scope in gas separation applications because of their merged inherent strength of a durable polymer matrix and the exceptional performance capabilities of inorganic fillers. The selection of comparatively suitable polymers with fillers that can match each other and boost interfacial compatibility while ensuring uniform dispersion of filler within the polymer is still intensively demanding and is challenging at the experimental scale. Ionic liquids (ILs) are effective in promoting better dispersion and compatibility, leading to improved separation performance. A computational molecular simulation approach is employed in current work to design a hybrid membrane having Trioctapropyl phosphonium bis(trifluoromethylsulfonyl)imide [P8883][Tf 2 N] IL decorated silica as a filler and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride-4,4'-oxydianiline (6FDA-ODA) polymer for carbon dioxide (CO 2 ) separation from methane (CH 4 ). Thermophysical and gas transport properties under pure and mixed gas condition (30, 50, and 70% CO 2 /CH 4 ) within the MMMs with varying filler loadings (5, 10, and 15 wt% IL-silica) are examined via Grand Canonical Monte Carlo (GCMC) and Molecular Dynamics (MD) simulations. Membrane characteristics like glass transition temperature ( T g ), Fractional Free Volume ( v f ), X-Ray Diffraction (XRD), solubility, diffusivity, permeability, and selectivity for neat and IL-silica filled 6FDA-ODA are computed. The results show that the T g of the composite membrane with 5 wt% IL-silica is found to be considerably higher (with 305 °C) than that of the pure 6FDA-ODA polymer having 298 °C. A higher T g value highlights the effective dispersion and higher adhesion between the filler and polymer membrane. Additionally, CO 2 permeability for 5 wt% IL-silica/6FDA-ODA MMM is significantly improved, measuring 319.0 barrer while maintaining a CO 2 /CH 4 selectivity of 16.2. These values are 89% and 56% respectively, greater than the corresponding values of neat 6FDA-ODA membrane. Published data from the literature review is used to validate the findings and guarantee their reliability. The obtained results exhibited an error in the range of 0.7-9%. Hence, it is concluded from the study that molecular simulation can be used to design IL decorated silica incorporated within 6FDA-ODA matrix, which is able to boost the interfacial compatibility, with elevated CO 2 /CH 4 selectivity and CO 2 permeability., Competing Interests: The authors assert that they do not possess any recognized conflicting financial concerns or personal bonds that may have seemed to affect the research presented in this manuscript., (This journal is © The Royal Society of Chemistry.)

The properties of (synthesized) single-walled aluminosilicate nanotube (AlSiNT; light-scattering characterized length ∼2000 ± 230 nm and diameter ∼35 ± 4 nm) dispersed in an aqueous poly(vinyl alcohol) (PVA) solution (10 wt %) are systematically explored using a comprehensive combination of (polarized/depolarized) dynamic light scattering, rheological, rheo-optical, and scanning electron microscopy analysis schemes. The nanotube/polymer dispersions under investigation are promising for their fair nanotube dispersion in pristine aqueous media (e.g., without salt or acid addition), as well as for the optical transparency that greatly facilitates systematic exploration of structural features and dispersion state that are practically inaccessible for many of their (opaque) companions such as carbon nanotube dispersions. We provide the first in-depth analysis revealing excellent dispersion state of (unmodified) AlSiNT in the PVA matrix, giving rise to (critical) gel-like features and substantially promoted elasticity that can be utilized, as a practical assessment, to produce uniform and defect-free electrospun nanofibers. Additionally, there is unambiguous evidence of nematic liquid crystal-like "wagging" (strain-invariant, periodic oscillation) under steady shear flow, a phenomenon previously unreported for nanotube composite materials. Overall, the present findings suggest that AlSiNT/PVA dispersions possess promising rheological, optical, and electrospinning properties that are highly desirable for current nanotechnological applications, and may serve as an ideal model system for establishing structure-performance relationships for like nanotube/polymer composite materials.