Effect of pH on the performance of polyamide/polyacrylonitrile based thin film composite membranes

Dalwani, Mayur; Benes, Nieck E.; Bargeman, Gerrald; Stamatialis, Dimitrios; Weßling, Matthias

doi:10.1016/j.memsci.2011.02.012

Cited by 130 publications

(70 citation statements)

References 57 publications

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“…To investigate the acid resistance of the NF membranes, two membranes (M0 and M4) were immersed in a H 2 SO 4 solution (pH < 2), and the salt rejection (for Na 2 SO 4 ) and water permeation were measured for fixed periods to evaluate the change in NF properties. As can be seen in Figure , the permeate flux of M0 increased from 26.1 L/m 2 h to 32.8 L/m 2 h, and the rejection for Na 2 SO 4 decreased from 98.3% to 91.1% after it was immersed in H 2 SO 4 for 216 h. This phenomenon is due to the instability of the amide bonds in the PA layer under acidic conditions, and the results are consistent with results reported in the literature . In a strongly acidic environment, the oxygen will rob some electron density from carbon because the oxygen is more electronegative.…”

Section: Resultssupporting

confidence: 89%

SiO₂‐modified nanocomposite nanofiltration membranes with high flux and acid resistance

Wei

et al. 2019

J of Applied Polymer Sci

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Thin‐film nanocomposite (TFN) nanofiltration (NF) membranes with superior properties were prepared using hydrophilic SiO2 (HGPN‐SiO2) nanoparticles as the inorganic modifying monomer by an interfacial polymerization (IP) process. The effects of HGPN‐SiO2 on the morphology and surface properties of the prepared NF membranes were characterized by attenuated total reflectance–Fourier transform infrared spectroscopy, field emission scanning electron microscopy, X‐ray photoelectron spectroscopy, atomic force microscopy, surface zeta potential, and static contact angle. The addition of HGPN‐SiO2 can effectively improve the permeate flux of the NF membranes. When the HGPN‐SiO2 concentration in the aqueous phase was 0.08 wt %, the permeate flux of the TFN‐NF membrane was twice that of the pure NF membrane. Furthermore, the acid resistance of the TFN‐NF membrane was clearly improved with the addition of HGPN‐SiO2. Under neutral conditions, the TFN‐NF membrane showed superior flux and salt rejection stability in a long‐running operation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47436.

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Section: Resultssupporting

confidence: 89%

SiO₂‐modified nanocomposite nanofiltration membranes with high flux and acid resistance

Wei

et al. 2019

J of Applied Polymer Sci

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“…Several authors have investigated this membrane and reported experimental results for the rejection ratio at different fluxes. By fitting the experimental data to the DSPM-DE model, it is found that the membrane has an average pore radius of 0.43 nm and an active layer thickness to porosity ratio of (Δx/A k ) about 1 μm [15,34]. The pore dielectric constant is 42.2 from fitting with experiments with sodiumchloride [15].…”

Section: = ( )mentioning

confidence: 98%

Modeling of flat-sheet and spiral-wound nanofiltration configurations and its application in seawater nanofiltration

Roy

Sharqawy

Lienhard

2015

Journal of Membrane Science

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a b s t r a c tThe Donnan Steric Pore Model with dielectric exclusion (DSPM-DE) is implemented over flat-sheet and spiral-wound leaves to develop a comprehensive model for nanofiltration modules. This model allows the user to gain insight into the physics of the nanofiltration process by allowing one to adjust and investigate effects of membrane charge, pore radius, and other membrane characteristics. The study shows how operating conditions such as feed flow rate and pressure affect the recovery ratio and solute rejection across the membrane. A comparison is made between the results for the flat-sheet and spiralwound configurations. The comparison showed that for the spiral-wound leaf, the maximum values of transmembrane pressure, flux and velocity occur at the feed entrance (near the permeate exit), and the lowest value of these quantities are at the diametrically opposite corner. This is in contrast to the flatsheet leaf, where all the quantities vary only in the feed flow direction. However it is found that the extent of variation of these quantities along the permeate flow direction in the spiral-wound membrane is negligibly small in most cases. Also, for identical geometries and operating conditions, the flat-sheet and spiral-wound configurations give similar results. Thus the computationally expensive and complex spiral-wound model can be replaced by the flat-sheet model for a variety of purposes. In addition, the model was utilized to predict the performance of a seawater nanofiltration system which has been validated with the data obtained from a large-scale seawater desalination plant, thereby establishing a reliable model for desalination using nanofiltration.

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“…d) Sodium chloride rejection comparison of the MPDTrip‐20 TFC membrane fabricated in this study with state‐of‐the‐art desalination membranes. Comparative data were obtained from the literature [ 33,60–65 ] with details listed in Table S14 in the Supporting Information.…”

Section: Figurementioning

confidence: 99%

Finely Tuned Submicroporous Thin‐Film Molecular Sieve Membranes for Highly Efficient Fluid Separations

et al. 2020

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promising energy efficient separation processes in the chemical separation industry. Its continued growth can be attributed to lower energy requirements translating to lower capital and operating cost as well as significantly reduced environmental impact compared to conventional thermal separation processes. Additionally, membrane technology offers the advantages of continuous process operation, modular design, and small system footprint and is predicted to be a main contributor to global energy-and carbon-reduction initiatives in the coming decades. [2] In 2008, the global membrane market was valued at ≈12 billion USD with a compound annual growth rate (CAGR) of ≈10%. [3] Reverse osmosis (RO) and nanofiltration (NF) membranes contribute significantly to the total global membrane sales with the majority of products comprising of variations of thin-film composite (TFC) membranes made by interfacial polymerization. Such highly crosslinked aromatic submicroporous (i.e., pore size < 4 Å) [4] polyamide TFC membranes-pioneered by John Cadotte-revolutionized the desalination industry due to their unprecedented combination of high water flux and salt rejection. [5][6][7][8] Surprisingly, despite their immense commercial success for aqueous RO and NF applications, the IP membrane formation process has not been implemented in other large-scale fluid separation processes, especially organic solvent nanofiltration (OSN) and gas separations. [9][10][11] Polymers of intrinsic microporosity (PIMs) are an emerging group of solution processible amorphous microporous materials (pore size < 20 Å) gaining significant attention in membranebased separations due to their ability to transcend the conventional permeability/selectivity trade-off relationships. [12][13][14][15] Such materials exhibit exceptionally high free volumes as a result of inefficient chain packing by architectural designs using highly rigid and contorted spirobisindane-, triptycene-, ethanoanthracene-, and Tröger's base-building blocks. [13,[16][17][18][19][20][21] To date, technical challenges associated with fabricating defect-free, inexpensive, thin-film composite membranes as well as the inability to achieve low-molecular-weight cutoffs (MWCOs) have severely limited the industrial use of PIM-based and similar membrane materials. For example, Cook et al. demonstrated successful Polymeric membranes with increasingly high permselective performances are gaining a significant role in lowering the energy burden and improving the environmental sustainability of complex chemical separations. However, the commercial deployment of newly designed materials with promising intrinsic properties for fluid separations has been stalled by challenges associated with fabrication and scale up of low-cost, high-performance, defect-free thin-film composite (TFC) membranes. Here, a facile method to fabricate next-generation TFC membranes using a bridged-bicyclic triptycene tetra-acyl chloride (Trip) building block with a large fraction of finely tuned structural submicroporosity (por...

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Effect of pH on the performance of polyamide/polyacrylonitrile based thin film composite membranes

Cited by 130 publications

References 57 publications

SiO₂‐modified nanocomposite nanofiltration membranes with high flux and acid resistance

SiO₂‐modified nanocomposite nanofiltration membranes with high flux and acid resistance

Modeling of flat-sheet and spiral-wound nanofiltration configurations and its application in seawater nanofiltration

Finely Tuned Submicroporous Thin‐Film Molecular Sieve Membranes for Highly Efficient Fluid Separations

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Effect of pH on the performance of polyamide/polyacrylonitrile based thin film composite membranes

Cited by 130 publications

References 57 publications

SiO2‐modified nanocomposite nanofiltration membranes with high flux and acid resistance

SiO2‐modified nanocomposite nanofiltration membranes with high flux and acid resistance

Modeling of flat-sheet and spiral-wound nanofiltration configurations and its application in seawater nanofiltration

Finely Tuned Submicroporous Thin‐Film Molecular Sieve Membranes for Highly Efficient Fluid Separations

Contact Info

Product

Resources

About

SiO₂‐modified nanocomposite nanofiltration membranes with high flux and acid resistance

SiO₂‐modified nanocomposite nanofiltration membranes with high flux and acid resistance