Micro-structured alumina multi-channel capillary tubes and monoliths

Lee, Melanie; Wu, Zhentao; Wang, Bo; Li, K.

doi:10.1016/j.memsci.2015.03.091

Cited by 38 publications

(18 citation statements)

References 19 publications

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“…During pressure-driven applications, the pressure applied could compact the membranes and change their microstructure, thus lowering the permeation flux. However, inorganic membranes such as ceramic membranes seldom experience compaction under high pressure because of their high rigidity [29]. GO membranes showed compaction consistently on both polymeric and ceramic substrates, and the compaction should not be caused by the substrates.…”

Section: Hierarchical Microstructure Of Go Membranesmentioning

confidence: 99%

Dynamic microstructure of graphene oxide membranes and the permeation flux

Chong

Wang

Mattevi

et al. 2018

Journal of Membrane Science

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112

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A B S T R A C TGraphene oxide (GO) membranes have been reported to be a promising separation barrier that can retain small molecules and multi-valent salts because of the well-defined interlayer space between GO flakes. However, while some studies suggested fast liquid transport through the extremely tortuous transport path, contradictory observations (e.g. low permeation flux) have also been obtained. This paper revealed the dynamic microstructure of GO membranes, which affected the membrane performance significantly. We showed that all GO membranes prepared by varied methods and on different substrates presented a severe reduction in water permeability during filtration, due to the compaction of their original loose microstructure. The water flux could drop continuously from tens of LMH bar −1 to < 0.1 LMH bar −1 after more than ten hours. This result demonstrated that the structure of GO membranes prepared by current approaches was far from the ideal laminar structure. The high permeability of GO membranes observed could be contributed by the disordered membrane microstructure. Therefore, the transport mechanisms assuming perfect laminar structure in GO membranes, and the fast transport hypothesis may not fully describe the water transport in GO membranes. Interestingly, the loosely packed microstructure of GO membranes was also found reversible depending on the storage conditions.

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Section: Hierarchical Microstructure Of Go Membranesmentioning

confidence: 99%

Dynamic microstructure of graphene oxide membranes and the permeation flux

Chong

Wang

Mattevi

et al. 2018

Journal of Membrane Science

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112

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“…Firstly, they can produce asymmetric membranes in a single step requiring one heat treatment session only, and secondly, the method is versatile and can be used to form a wide range of different membrane configurations: flat discs, hollow fibres, multi-channel monoliths, etc [1][2][3][4]. The ability to form finger-like micro-channels in the membranes due to interfacial instabilities not only reduces mass transfer resistance, giving rise to competitive pure water permeation fluxes, but also widens the possible applications of these ceramic membranes [4][5][6][7][8][9][10][11].…”

Section: Introductionmentioning

confidence: 99%

“…Furthermore, the micro-channels are desirable crevices where catalysts or other active components can be deposited or coated to form hybrid systems [1,12], but the existence of the dense surfaces prohibit access to these micro-channels unless solution techniques are employed.…”

Section: Introductionmentioning

confidence: 99%

New designs of ceramic hollow fibres toward broadened applications

Lee

Wang

2016

Journal of Membrane Science

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Three structural designs for ceramic membranes have been achieved for the first time through the co-extrusion of polymeric and ceramic layers. During co-extrusion, micro-channels are initiated due to the Rayleigh-Taylor instability and they propagate through the different layers.The polymeric layer(s) is then calcined off during the heat treatment step, which opens the microchannels and following sintering a ceramic membrane with open micro-channels ranging from a few to a few tens of micrometres in diameter can be formed. These long, straight and nontortuous micro-channels can be controlled to be open at any or all of the surfaces. Design 1 has open micro-channels passing through the entire membrane wall, Design 2 has a separation layer at the lumen and open micro-channels at the shell side, and Design 3 has open micro-channels from both lumen and shell sides sandwiching a separation layer of sponge-like structure. Aside from having much improved mass transfer property due to the reduced effective membrane thickness, they can be easily incorporated into hybrid systems with anticipated improvements in unit compactness and performance. The pure water permeation of Design 2 reached up to 159, 000 L/m 2 h bar with pore sizes in the micro-filtration range. The micro-channels are easily accessible from the shell/lumen side; therefore catalysts or adsorbents can be easily deposited into the micro-channels. Examples of possible applications include a high-efficiency dispersing device realised with Design 1; a gas chromatography column for gas separation with very low pressure drop realised with Design 2 and a highly compact membrane micro-reactor for consecutive reactions proposed with Design 3.

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“…Na Figura 3 observa-se que o fluxo de água aumenta linearmente em relação a pressão aplicada (Fakhfakh et al, 2010), podendo ser representada por uma função linear (Lee et al, 2015). O aumento da pressão transmembrana proporciona aumento no fluxo de permeado devido a força motriz (Hwang e Sz, 2011;Bhattacharya et al, 2013 …”

Section: Permeabilidade Hidráulicaunclassified