Deriving a CO₂‑Permselective Carbon Membrane from a Multilayered Matrix of Polyion Complexes

A multilayered assembly consisting of polyion complexes was developed over porous ceramic as a unique precursor for a carbon membrane (CM). This specific layer was attained through in situ polymerization of <i>N</i>-methylpyrrole (mPy) over a prime coating layer of poly­(4-styrenesulfonic acid) (PSSA) with an embedded oxidant on the ceramic surface. Extensive ion-pair complexation between the sulfonic acid groups of PSSA and the tertiary amine groups of the resulting poly­(<i>N</i>-methylpyrrole) (PmPy) sustains this assembly layer. Incorporating cetyltrimethylammonium bromide (CTAB) into the PSSA is critical in facilitating the infiltration of mPy into the PSSA layer and promoting interfacial contact between the two polymers. Upon pyrolysis, the precursor coating was collectively converted into a carbon composite matrix. Such copyrolysis restrains the grain sizes of the carbonized PmPy, thereby halting defects in the resultant carbonaceous matrix. The gas separation performances of the CMs obtained at various graphitization temperatures showed that the least graphitized carbon matrix exhibited the best selectivity of CO₂/CH₄ = 167 with a CO₂ permeability of 7.19 Barrer. This specific feature is attributed to both imine and imide pendant groups that function as selective adsorption sites for CO₂ in the carbon skeleton

Trophic Magnification and Isomer Fractionation of Perfluoroalkyl Substances in the Food Web of Taihu Lake, China

Biomagnification of perfluoroalkyl substances (PFASs) are well studied in marine food webs, but related information in fresh water ecosystem and knowledge on fractionation of their isomers along the food web are limited. The distribution, bioaccumulation, magnification, and isomer fractionation of PFASs were investigated in a food web of Taihu Lake, China. Perfluorooctanesulfonate (PFOS) and perfluorocarboxylates (PFCAs) with longer carbon chain lengths, such as perfluorodecanoate (PFDA) and perfluoroundecanoate (PFUnA), were predominant in organisms, while perfluorohexanoate (PFHxA) and perfluorooctanoate (∑PFOA) contributed more in the water phase. The consistent profile signature of PFOA isomers in water phase with 3M electrochemical fluorination (ECF) products suggests that ECF production of PFOA still exists in China. Linear proportions of PFOA, PFOS and perfluorooctane sulfonamide (PFOSA) in the biota were in the range of 91.9–100%, 78.6–95.5%, and 72.2–95.5%, respectively, indicating preferential bioaccumulation of linear isomers in biota. Trophic magnification factors (TMFs) were estimated for PFDA (2.43), perfluorododecanoate (PFDoA) (2.68) and PFOS (3.46) when all biota were included, suggesting that PFOS and long-chained PFCAs are biomagnified in the fresh water food web. The TMF of PFOS isomers descended in the order: <i>n</i>-PFOS (3.86) > 3+5<i>m</i>-PFOS (3.35) > 4<i>m</i>-PFOS (3.32) > 1<i>m</i>-PFOS (2.92) > <i>m</i>₂-PFOS (2.67) > <i>iso</i>-PFOS (2.59), which is roughly identical to their elution order on a FluoroSep-RP Octyl column, suggesting that hydrophobicity may be an important contributor for isomer discrimination in biota

Enhancing the Performance of Viscous Electrode-Based Flow Batteries Using Lubricant-Impregnated Surfaces

Redox flow batteries are a promising technology that can potentially meet the large-scale grid storage needs of renewable power sources. Today, most redox flow batteries are based on aqueous solutions with low cell voltages and low energy densities that lead to significant costs from hardware and balance-of-plant. Nonaqueous electrochemical couples offer higher cell voltages and higher energy densities and can reduce system-level costs but tend toward higher viscosities and can exhibit non-Newtonian rheology that increases the power required to drive flow. This work uses lubricant-impregnated surfaces (LIS) to promote flow in electrochemical systems and outlines their design based on interfacial thermodynamics and electrochemical stability. We demonstrate up to 86% mechanical power savings at low flow rates for LIS compared to conventional surfaces for a lithium polysulfide flow electrode in a half-cell flow battery configuration. The measured specific charge capacity of ∼800 mAh/(g·S) is a 4-fold increase over previous work

Enhancing the Performance of Viscous Electrode-Based Flow Batteries Using Lubricant-Impregnated Surfaces

Redox flow batteries are a promising technology that can potentially meet the large-scale grid storage needs of renewable power sources. Today, most redox flow batteries are based on aqueous solutions with low cell voltages and low energy densities that lead to significant costs from hardware and balance-of-plant. Nonaqueous electrochemical couples offer higher cell voltages and higher energy densities and can reduce system-level costs but tend toward higher viscosities and can exhibit non-Newtonian rheology that increases the power required to drive flow. This work uses lubricant-impregnated surfaces (LIS) to promote flow in electrochemical systems and outlines their design based on interfacial thermodynamics and electrochemical stability. We demonstrate up to 86% mechanical power savings at low flow rates for LIS compared to conventional surfaces for a lithium polysulfide flow electrode in a half-cell flow battery configuration. The measured specific charge capacity of ∼800 mAh/(g·S) is a 4-fold increase over previous work

Enhancing the Performance of Viscous Electrode-Based Flow Batteries Using Lubricant-Impregnated Surfaces

Redox flow batteries are a promising technology that can potentially meet the large-scale grid storage needs of renewable power sources. Today, most redox flow batteries are based on aqueous solutions with low cell voltages and low energy densities that lead to significant costs from hardware and balance-of-plant. Nonaqueous electrochemical couples offer higher cell voltages and higher energy densities and can reduce system-level costs but tend toward higher viscosities and can exhibit non-Newtonian rheology that increases the power required to drive flow. This work uses lubricant-impregnated surfaces (LIS) to promote flow in electrochemical systems and outlines their design based on interfacial thermodynamics and electrochemical stability. We demonstrate up to 86% mechanical power savings at low flow rates for LIS compared to conventional surfaces for a lithium polysulfide flow electrode in a half-cell flow battery configuration. The measured specific charge capacity of ∼800 mAh/(g·S) is a 4-fold increase over previous work

Enhancing the Performance of Viscous Electrode-Based Flow Batteries Using Lubricant-Impregnated Surfaces

Redox flow batteries are a promising technology that can potentially meet the large-scale grid storage needs of renewable power sources. Today, most redox flow batteries are based on aqueous solutions with low cell voltages and low energy densities that lead to significant costs from hardware and balance-of-plant. Nonaqueous electrochemical couples offer higher cell voltages and higher energy densities and can reduce system-level costs but tend toward higher viscosities and can exhibit non-Newtonian rheology that increases the power required to drive flow. This work uses lubricant-impregnated surfaces (LIS) to promote flow in electrochemical systems and outlines their design based on interfacial thermodynamics and electrochemical stability. We demonstrate up to 86% mechanical power savings at low flow rates for LIS compared to conventional surfaces for a lithium polysulfide flow electrode in a half-cell flow battery configuration. The measured specific charge capacity of ∼800 mAh/(g·S) is a 4-fold increase over previous work

Enhancing the Performance of Viscous Electrode-Based Flow Batteries Using Lubricant-Impregnated Surfaces

Redox flow batteries are a promising technology that can potentially meet the large-scale grid storage needs of renewable power sources. Today, most redox flow batteries are based on aqueous solutions with low cell voltages and low energy densities that lead to significant costs from hardware and balance-of-plant. Nonaqueous electrochemical couples offer higher cell voltages and higher energy densities and can reduce system-level costs but tend toward higher viscosities and can exhibit non-Newtonian rheology that increases the power required to drive flow. This work uses lubricant-impregnated surfaces (LIS) to promote flow in electrochemical systems and outlines their design based on interfacial thermodynamics and electrochemical stability. We demonstrate up to 86% mechanical power savings at low flow rates for LIS compared to conventional surfaces for a lithium polysulfide flow electrode in a half-cell flow battery configuration. The measured specific charge capacity of ∼800 mAh/(g·S) is a 4-fold increase over previous work

Enhancing the Performance of Viscous Electrode-Based Flow Batteries Using Lubricant-Impregnated Surfaces

Redox flow batteries are a promising technology that can potentially meet the large-scale grid storage needs of renewable power sources. Today, most redox flow batteries are based on aqueous solutions with low cell voltages and low energy densities that lead to significant costs from hardware and balance-of-plant. Nonaqueous electrochemical couples offer higher cell voltages and higher energy densities and can reduce system-level costs but tend toward higher viscosities and can exhibit non-Newtonian rheology that increases the power required to drive flow. This work uses lubricant-impregnated surfaces (LIS) to promote flow in electrochemical systems and outlines their design based on interfacial thermodynamics and electrochemical stability. We demonstrate up to 86% mechanical power savings at low flow rates for LIS compared to conventional surfaces for a lithium polysulfide flow electrode in a half-cell flow battery configuration. The measured specific charge capacity of ∼800 mAh/(g·S) is a 4-fold increase over previous work

Comparison of sugarcane stem node identification methods.

Comparison of sugarcane stem node identification methods.</p

Comparison of different one-stage detection algorithms.

Comparison of different one-stage detection algorithms.</p