Positron Annihilation Spectroscopic Evidence to Demonstrate the Flux-Enhancement Mechanism in Morphology-Controlled Thin-Film-Composite (TFC) Membrane

2005 ◽  
Vol 39 (6) ◽  
pp. 1764-1770 ◽  
Author(s):  
Sung Ho Kim ◽  
Seung-Yeop Kwak ◽  
Takenori Suzuki
Keyword(s):  
Thin Film ◽  
Positron Annihilation ◽  
Film Composite ◽  
Spectroscopic Evidence ◽  
Enhancement Mechanism ◽  
Flux Enhancement ◽  
Thin Film Composite ◽  
Tfc Membrane

scholarly journals Morphology of Thin Film Composite Membranes Explored by Small-Angle Neutron Scattering and Positron-Annihilation Lifetime Spectroscopy

Membranes ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 48 ◽  
Author(s):  
Vitaliy Pipich ◽  
Marcel Dickmann ◽  
Henrich Frielinghaus ◽  
Roni Kasher ◽  
Christoph Hugenschmidt ◽  
...  
Keyword(s):  
Thin Film ◽  
Neutron Scattering ◽  
Positron Annihilation ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Positron Annihilation Lifetime Spectroscopy ◽  
Film Composite ◽  
Positron Annihilation Lifetime ◽  
Thin Film Composite

The morphology of thin film composite (TFC) membranes used in reverse osmosis (RO) and nanofiltration (NF) water treatment was explored with small-angle neutron scattering (SANS) and positron-annihilation lifetime spectroscopy (PALS). The combination of both methods allowed the characterization of the bulk porous structure from a few Å to µm in radius. PALS shows pores of ~4.5 Å average radius in a surface layer of about 4 μm thickness, which become ~40% smaller at the free surface of the membranes. This observation may correlate with the glass state of the involved polymer. Pores of similar size appear in SANS as closely packed pores of ~6 Å radius distributed with an average distance of ~30 Å. The main effort of SANS was the characterization of the morphology of the porous polysulfone support layer as well as the fibers of the nonwoven fabric layer. Contrast variation using the media H2O/D2O and supercritical CO2 and CD4 identified the polymers of the support layers as well as internal heterogeneities.

The role of carboxylated cellulose nanocrystals placement in the performance of thin-film composite (TFC) membrane

2021 ◽  
Vol 617 ◽  
pp. 118581 ◽  
Author(s):  
Yatao Liu ◽  
Langming Bai ◽  
Xuewu Zhu ◽  
Daliang Xu ◽  
Guibai Li ◽  
...  
Keyword(s):  
Thin Film ◽  
Cellulose Nanocrystals ◽  
Film Composite ◽  
Thin Film Composite ◽  
Tfc Membrane

scholarly journals Flux enhancement of thin-film composite membrane by graphene oxide incorporation

2019 ◽  
Vol 17 (1) ◽  
pp. 377-382
Author(s):  
Sajjad Jalali ◽  
Abdollah Rashidi Mehrabadi ◽  
Jalal Shayegan ◽  
Maryam Mirabi ◽  
Sayed Siavash Madaeni
Keyword(s):  
Thin Film ◽  
Graphene Oxide ◽  
Composite Membrane ◽  
Film Composite ◽  
Flux Enhancement ◽  
Thin Film Composite Membrane ◽  
Thin Film Composite

scholarly journals Antifouling Property of Oppositely Charged Titania Nanosheet Assembled on Thin Film Composite Reverse Osmosis Membrane for Highly Concentrated Oily Saline Water Treatment

Membranes ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 237
Author(s):  
Nor Akalili Ahmad ◽  
Pei Sean Goh ◽  
Abdul Karim Zulhairun ◽  
Ahmad Fauzi Ismail
Keyword(s):  
Thin Film ◽  
Wastewater Treatment ◽  
Reverse Osmosis ◽  
Saline Water ◽  
High Concentration ◽  
Saline Wastewater ◽  
Film Composite ◽  
Thin Film Composite ◽  
Tfc Membrane ◽  
Ro Membrane

With the blooming of oil and gas industries, oily saline wastewater treatment becomes a viable option to resolve the oily water disposal issue and to provide a source of water for beneficial use. Reverse osmosis (RO) has been touted as a promising technology for oily saline wastewater treatment. However, one great challenge of RO membrane is fouling phenomena, which is caused by the presence of hydrocarbon contents in the oily saline wastewater. This study focuses on the fabrication of antifouling RO membrane for accomplishing simultaneous separation of salt and oil. Thin film nanocomposite (TFN) RO membrane was formed by the layer by layer (LbL) assembly of positively charged TNS (pTNS) and negatively charged TNS (nTNS) on the surface of thin film composite (TFC) membrane. The unique features, rendered by hydrophilic TNS bilayer assembled on TFC membrane in the formation of a hydration layer to enhance the fouling resistance by high concentration oily saline water while maintaining the salt rejection, were discussed in this study. The characterization findings revealed that the surface properties of membrane were improved in terms of surface hydrophilicity, surface roughness, and polyamide(PA) cross-linking. The TFC RO membrane coated with 2-bilayer of TNS achieved >99% and >98% for oil and salt rejection, respectively. During the long-term study, the 2TNS-PA TFN membrane outperformed the pristine TFC membrane by exhibiting high permeability and much lower fouling propensity for low to high concentration of oily saline water concentration (1000 ppm, 5000 ppm and 10,000 ppm) over a 960 min operation. Meanwhile, the average permeability of uncoated TFC membrane could only be recovered by 95.7%, 89.1% and 82.9% for 1000 ppm, 5000 ppm and 10,000 ppm of the oily saline feedwater, respectively. The 2TNS-PA TFN membrane achieved almost 100% flux recovery for three cycles by hydraulic washing.

Flux enhancement of thin film composite RO membrane by controlled chlorine treatment

Desalination ◽  
2010 ◽  
Vol 250 (3) ◽  
pp. 945-949 ◽  
Author(s):  
H.D. Raval ◽  
J.J. Trivedi ◽  
S.V. Joshi ◽  
C.V. Devmurari
Keyword(s):  
Thin Film ◽  
Film Composite ◽  
Flux Enhancement ◽  
Thin Film Composite ◽  
Ro Membrane

scholarly journals Interfacially polymerized thin-film composite polyamide membrane: positron annihilation spectroscopic study, characterization and pervaporation performance

2010 ◽  
Vol 42 (3) ◽  
pp. 242-248 ◽  
Author(s):  
Se-Tsung Kao ◽  
Shu-Hsien Huang ◽  
Der-Jang Liaw ◽  
Wei-Chi Chao ◽  
Chien-Chieh Hu ◽  
...  
Keyword(s):  
Thin Film ◽  
Spectroscopic Study ◽  
Positron Annihilation ◽  
Film Composite ◽  
Thin Film Composite ◽  
Polyamide Membrane

scholarly journals Modification of Nanofiber Support Layer for Thin Film Composite forward Osmosis Membranes via Layer-by-Layer Polyelectrolyte Deposition

Membranes ◽  
2018 ◽  
Vol 8 (3) ◽  
pp. 70 ◽  
Author(s):  
Ralph Gonzales ◽  
Myoung Park ◽  
Leonard Tijing ◽  
Dong Han ◽  
Sherub Phuntsho ◽  
...  
Keyword(s):  
Thin Film ◽  
High Performance ◽  
Forward Osmosis ◽  
Composite Membranes ◽  
Structural Parameter ◽  
Layer By Layer ◽  
Film Composite ◽  
Thin Film Composite ◽  
Layer Deposition ◽  
Tfc Membrane

Electrospun nanofiber-supported thin film composite membranes are among the most promising membranes for seawater desalination via forward osmosis. In this study, a high-performance electrospun polyvinylidenefluoride (PVDF) nanofiber-supported thin film composite (TFC) membrane was successfully fabricated after molecular layer-by-layer polyelectrolyte deposition. Negatively-charged electrospun polyacrylic acid (PAA) nanofibers were deposited on electrospun PVDF nanofibers to form a support layer consisted of PVDF and PAA nanofibers. This resulted to a more hydrophilic support compared to the plain PVDF nanofiber support. The PVDF-PAA nanofiber support then underwent a layer-by-layer deposition of polyethylenimine (PEI) and PAA to form a polyelectrolyte layer on the nanofiber surface prior to interfacial polymerization, which forms the selective polyamide layer of TFC membranes. The resultant PVDF-LbL TFC membrane exhibited enhanced hydrophilicity and porosity, without sacrificing mechanical strength. As a result, it showed high pure water permeability and low structural parameter values of 4.12 L m−2 h−1 bar−1 and 221 µm, respectively, significantly better compared to commercial FO membrane. Layer-by-layer deposition of polyelectrolyte is therefore a useful and practical modification method for fabrication of high performance nanofiber-supported TFC membrane.

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