Surface modification of porous alumina filters for CO2 separation using silane coupling agents

Takahashi, Tsuyoshi; Tanimoto, Remi; Isobe, Toshihiro; Matsushita, Sachiko; Nakajima, Akira

doi:10.1016/j.memsci.2015.09.007

Cited by 13 publications

(8 citation statements)

References 15 publications

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“…One approach to enhancing the selectivity of a gas permeated through porous ceramics is to modify the surfaces of ceramic particles by an agent that interacts with a gas and suppresses the permeation of the other mixed gas (e.g., AlOOH [ 14 ] and silane coupling agents [ 15 ] interact with CO 2 gas). In this work, we used another approach to enhance the selectivity of a gas permeated through porous ceramics.…”

Section: Introductionmentioning

confidence: 99%

Separation of Hydrogen from Carbon Dioxide through Porous Ceramics

et al. 2016

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The gas permeability of α-alumina, yttria-stabilized zirconia (YSZ), and silicon carbide porous ceramics toward H2, CO2, and H2–CO2 mixtures were investigated at room temperature. The permeation of H2 and CO2 single gases occurred above a critical pressure gradient, which was smaller for H2 gas than for CO2 gas. When the Knudsen number (λ/r ratio, λ: molecular mean free path, r: pore radius) of a single gas was larger than unity, Knudsen flow became the dominant gas transportation process. The H2 fraction for the mixed gas of (20%–80%) H2–(80%–20%) CO2 through porous Al2O3, YSZ, and SiC approached unity with decreasing pressure gradient. The high fraction of H2 gas was closely related to the difference in the critical pressure gradient values of H2 and CO2 single gas, the inlet mixed gas composition, and the gas flow mechanism of the mixed gas. Moisture in the atmosphere adsorbed easily on the porous ceramics and affected the critical pressure gradient, leading to the increased selectivity of H2 gas.

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Section: Introductionmentioning

confidence: 99%

Separation of Hydrogen from Carbon Dioxide through Porous Ceramics

et al. 2016

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Section: Resultsmentioning

confidence: 99%

“…On the other hand, membrane selectivity beyond Knudsen selectivity was observed on an annealed MMM coated with 0.03 mol TMOS. Because the optimal silane coating on the membrane surface provides an electrical charge distribution on the membrane, it implies that the charge produces a difference in gas separation behaviour [66]. Takahashi et al reported that at the surface of the porous alumina structure, oppositely charged atoms promote a physical interaction between the CO 2 molecule and the silane coupling agent [66].…”

Section: Overview Of Gas Separation Performancementioning

confidence: 99%

“…Because the optimal silane coating on the membrane surface provides an electrical charge distribution on the membrane, it implies that the charge produces a difference in gas separation behaviour [66]. Takahashi et al reported that at the surface of the porous alumina structure, oppositely charged atoms promote a physical interaction between the CO 2 molecule and the silane coupling agent [66]. This is to the fact that the CH 4 molecule is non-polar, while CO 2 has a polarity, thus providing a greater permeation of CO 2 than CH 4 .…”

Section: Overview Of Gas Separation Performancementioning

confidence: 99%

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Annealing and TMOS coating on PSF/ZTC mixed matrix membrane for enhanced CO₂/CH₄and H₂/CH₄separation

et al. 2022

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Recently, natural gas (mostly methane) is frequently used as fuel, while hydrogen is a promising renewable energy source. However, each gas produced contains impurity gases. As a result, membrane separation is required. The mixed matrix membrane (MMM) is a promising membrane. The huge surface area and well-defined pore structure of zeolite templated carbon (ZTC)-based MMM allow for effective separation. However, the interfacial vacuum in MMM is difficult to avoid, contributing to poor separation performance. This research tries to improve separation performance by altering membrane surfaces. MMM PSF/ZTC was modified by annealing at 120, 150, and 190°C; coating using 0.01, 0.03, and 0.05 mol tetramethyl orthosilicate (TMOS); and a combination of both, i.e. annealing at 190°C and coating using 0.03 mol TMOS. MMM PSF/ZTC successfully significantly improved CO 2 /CH 4 selectivity by a combination of annealing at 190°C and coating 0.03 mol TMOS from 1.37 to 5.90 (331%), and H 2 /CH 4 selectivity by coating with 0.03 mol TMOS from 4.58 to 65.76 (1378%). The enhancement of selectivity was due to structural changes to the membrane that became denser and smoother, which SEM and AFM observed. In this study, annealing and coating treatments are the methods investigated for improving the polymer matrix and filler particle adhesion.

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“…The power density of the Nafion/MOR-GMPTS membrane was 1.11 times that of the recast Nafion membrane. A silane coupling agent was also used to modify zeolite surface for membranes used in gas separation [29,34]. Li et al [29] reported that the permeability and selectivity of membranes made from silane modified zeolite were higher than those of membrane made from unmodified zeolite because the degree of partial pore blockage was decreased.…”

Section: Introductionmentioning

confidence: 99%

Surface modification of mordenite in Nafion composite membrane for direct ethanol fuel cell and its characterizations: Effect of types of silane coupling agent

Prapainainar

Kanjanapaisit

Kongkachuichay

et al. 2016

Journal of Environmental Chemical Engineering

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(P. Prapainainar).2 Highlight  Silane treated mordenite composite membrane was used for DEFC.  Four types of silane coupling agents were treated on MOR surface.  Sulfhydryl group in MPTES provided sulfonic group for enhance proton conductivity.  MOR-MPTES/Nafion membrane had the highest selectivity at all temperature. AbstractMordenite (MOR) has been used to solve the alcohol crossover in direct ethanol fuel cells. However, the lack of compatibility has been a problem. This paper shows the compatibility improvement of MOR in a Nafion composite membrane for use in a fuel cell using four types of silane coupling agents: gamma-glycidoxypropyltrimethoxysilane (GMPTS), (3-mercaptopropyl) trimethoxysilane (MPTS), (3-Mercaptopropyl) triethoxysilane (MPTES) and (3-Mercaptopropyl) methyl-dimethoxysilane (MPDMS). The coupling agents were used to treat the MOR surface before mixing with Nafion. Each type of silane was treated carefully and differently, depending on its structure. Their characterizations were also described. The results showed that better compatibility and a noticeable reduction in ethanol permeability were achieved when using all silane-treated MOR in the composite. It was found that the Nafion/MOR-MPTES membrane had the highest proton conductivity at all temperature ranges from 30-70 o C. This was due to the fact that the sulfhydryl (-SH) functional group in MPTES provided the sulfonic group in its structure after the oxidation in the surface treatment process. These sulfonic groups at the MOR surface facilitated proton transport and improved the selectivity of the membrane.

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Surface modification of porous alumina filters for CO2 separation using silane coupling agents

Cited by 13 publications

References 15 publications

Separation of Hydrogen from Carbon Dioxide through Porous Ceramics

Separation of Hydrogen from Carbon Dioxide through Porous Ceramics

Annealing and TMOS coating on PSF/ZTC mixed matrix membrane for enhanced CO₂/CH₄and H₂/CH₄separation

Surface modification of mordenite in Nafion composite membrane for direct ethanol fuel cell and its characterizations: Effect of types of silane coupling agent

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Surface modification of porous alumina filters for CO2 separation using silane coupling agents

Cited by 13 publications

References 15 publications

Separation of Hydrogen from Carbon Dioxide through Porous Ceramics

Separation of Hydrogen from Carbon Dioxide through Porous Ceramics

Annealing and TMOS coating on PSF/ZTC mixed matrix membrane for enhanced CO2/CH4and H2/CH4separation

Surface modification of mordenite in Nafion composite membrane for direct ethanol fuel cell and its characterizations: Effect of types of silane coupling agent

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Annealing and TMOS coating on PSF/ZTC mixed matrix membrane for enhanced CO₂/CH₄and H₂/CH₄separation