Investigating the structure and water permeation of membranes modified with natural and synthetic additives using tensile, porosity, and glass transition temperature studies

Vilakati, Gcina D.; Hoek, Eric M.V.; Mamba, Bhekie B.

doi:10.1002/app.40616

Cited by 16 publications

(9 citation statements)

References 39 publications

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“…The device consists of microchannels, nanoporous filtering membrane, and sealing plates. The filtering membrane is made of PES, using a liquid inversion method to create a thickness of 100 μm [ 19 , 20 ]. PES with a molecular weight of 4800 (Sumitomo Chemical Co., Tokyo, Japan), polyethylene glycol with a molecular weight of 400 (FUJIFILM Wako Chemical Corporation, Osaka, Japan) and dimethylacetamide (DMAc) (FUJIFILM Wako Chemical Corporation) were mixed in ratios of 17.5 wt%, 14.6 wt%, and 67.9 wt%.…”

Section: Device Design and Experimental Methodsmentioning

confidence: 99%

Pump-Free Microfluidic Hemofiltration Device

et al. 2021

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Hemofiltration removes water and small molecules from the blood via nanoporous filtering membranes. This paper discusses a pump-free hemofiltration device driven by the pressure difference between the artery and the vein. In the design of the filtering device, oncotic pressure needs to be taken into consideration. Transmembrane pressure (TMP) determines the amount and direction of hemofiltration, which is calculated by subtracting the oncotic pressure from the blood pressure. Blood pressure decreases as the channels progress from the inlet to the outlet, while oncotic pressure increases slightly since no protein is removed from the blood to the filtrate in hemofiltration. When TMP is negative, the filtrate returns to the blood, i.e., backfiltration takes place. A small region of the device with negative TMP would thus result in a small amount of or even zero filtrates. First, we investigated this phenomenon using in vitro experiments. We then designed a hemofiltration system taking backfiltration into consideration. We divided the device into two parts. In the first part, the device has channels for the blood and filtrate with a nanoporous membrane. In the second part, the device does not have channels for filtration. This design ensures TMP is always positive in the first part and prevents backfiltration. The concept was verified using in vitro experiments and ex vivo experiments in beagle dogs. Given the simplicity of the device without pumps or electrical components, the proposed pump-free hemofiltration device may prove useful for either implantable or wearable hemofiltration.

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Section: Device Design and Experimental Methodsmentioning

confidence: 99%

Pump-Free Microfluidic Hemofiltration Device

et al. 2021

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“…In terms of porosity, the PSf/IONPs membrane is more porous as compared to the neat PSf membrane. This enhanced membrane porosity is due to the increase in the number of finger‐like structure that are formed . However, the average pore size of the membrane becomes smaller after the addition of IONPs.…”

Section: Resultsmentioning

confidence: 99%

Enhanced hydrophilic polysulfone hollow fiber membranes with addition of iron oxide nanoparticles

et al. 2017

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Membranes are at the heart of hemodialysis treatment functions to remove excess metabolic waste such as urea. However, membranes made up of pure polymers and hydrophilic polymers such as polyvinylpyrrolidone suffer problems of low flux and bio-incompatibility. Hence, this study aimed to improve polysulfone (PSf) membrane surface properties by the addition of iron oxide nanoparticles (IONPs). The membrane surface properties and separation performance of neat PSf membrane and membrane filled with IONPs at a loading of 0.2 wt% were investigated and compared. The membranes were characterized in terms of morphology, pure water permeability (PWP) and protein rejection using bovine serum albumin (BSA). A decrease in contact angle value from 66.62 ∘ to 46.23 ∘ for the PSf/IONPs membrane indicated an increase in surface hydrophilicity that caused positive effects on the PWP and BSA rejection of the membrane. The PWP increased by 40.74% to 57.04 L m −2 h −1 bar −1 when IONPs were incorporated due to the improved interaction with water molecules. Furthermore, the PSf/IONPs membrane rejected 96.43% of BSA as compared to only 91.14% by the neat PSf membrane. Hence, the incorporation of IONPs enhanced the PSf hollow fiber membrane hydrophilicity and consequently improved the separation performance of the membrane for hemodialysis application.

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“…This observation highlights the importance of using the fabrics when fabricating membranes. Unsupported membranes are known to form a thick bottom skin which increases the tortuosity and hence the structural parameter [43]. Fabric TH produced a membrane with a structural parameter which is 2.6 times less than the expected value (821 mm).…”

Section: Phase Inverted Composite Membranesmentioning

confidence: 99%