scholarly journals Hollow-Fiber RO Membranes Fabricated via Adsorption of Low-Charge Poly(vinyl alcohol) Copolymers

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 981
Author(s):  
Takashi Ohkame ◽  
Kazushi Minegishi ◽  
Hideki Sugihara ◽  
Keizo Nakagawa ◽  
Takuji Shintani ◽  
...  
Keyword(s):  
Hollow Fiber ◽  
Vinyl Alcohol ◽  
Hollow Fiber Membrane ◽  
Poly Vinyl Alcohol ◽  
Separation Performance ◽  
Layer By Layer ◽  
Self Organized ◽  
Ro Membrane ◽  
20 Nm ◽  
Low Charge

We report a new type of alkaline-stable hollow-fiber reverse osmosis (RO) membrane with an outside-in configuration that was established via adsorption of positively charged poly(vinyl alcohol) copolymers containing a small amount of quaternary ammonium moieties. Anionic sulfonated poly(arylene ether sulfone nitrile) hollow-fiber membranes were utilized as a substrate upon which the cationic copolymer layer was self-organized via electrostatic interaction. While the adsorption of the low-charge copolymer on the membrane support proceeded in a Layer-by-Layer (LbL) fashion, it was found that the adsorbed amount by one immersion step was enough to form a defect-free separation layer with a thickness of around 20 nm after cross-linking of vinyl alcohol units with glutaraldehyde. The resultant hollow-fiber membrane showed excellent desalination performances (NaCl rejection of 98.3% at 5 bar and 1500 mg/L), which is comparable with commercial low-pressure polyamide RO membranes, as well as good alkaline resistance. The separation performance could be restored by repeating the LbL treatment after alkaline degradation. Such features of LbL membranes may contribute to extending RO membrane lifetimes.

scholarly journals Fabrication of Polydimethysiloxane (PDMS) Dense Layer on Polyetherimide (PEI) Hollow Fiber Support for the Efficient CO2/N2 Separation Membranes

Polymers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 756
Author(s):  
Guoqiang Li ◽  
Katarzyna Knozowska ◽  
Joanna Kujawa ◽  
Andrius Tonkonogovas ◽  
Arūnas Stankevičius ◽  
...  
Keyword(s):  
Gas Separation ◽  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Dip Coating ◽  
Separation Performance ◽  
Dense Layer ◽  
Pdms Layer ◽  
Coating Method ◽  
Coating Time ◽  
Dip Coating Method

The development of thin layer on hollow-fiber substrate has drawn great attention in the gas-separation process. In this work, polydimethysiloxane (PDMS)/polyetherimide (PEI) hollow-fiber membranes were prepared by using the dip-coating method. The prepared membranes were characterized by Scanning Electron Microscope (SEM), energy-dispersive X-ray spectroscopy (EDX), and gas permeance measurements. The concentration of PDMS solution and coating time revealed an important influence on the gas permeance and the thickness of the PDMS layer. It was confirmed from the SEM and EDX results that the PDMS layer’s thickness and the atomic content of silicon in the selective layer increased with the growth in coating time and the concentration of PDMS solution. The composite hollow-fiber membrane prepared from 15 wt% PDMS solution at 10 min coating time showed the best gas-separation performance with CO2 permeance of 51 GPU and CO2/N2 ideal selectivity of 21.

Cellulose acetate/poly(vinyl alcohol) hybrid fibrous mat containing tetracycline hydrochloride and phenytoin sodium: Morphology, drug release, antibacterial, and cell culture studies

2018 ◽  
Vol 33 (6) ◽  
pp. 597-611 ◽  
Author(s):  
Hamed Souriyan-Reyhani pour ◽  
Ramin Khajavi ◽  
Mohammad Esmaeil Yazdanshenas ◽  
Payam Zahedi ◽  
Mohammad Mirjalili
Keyword(s):  
Drug Release ◽  
Cellulose Acetate ◽  
Vinyl Alcohol ◽  
Aqueous Media ◽  
Tetracycline Hydrochloride ◽  
Diameter Distribution ◽  
Poly Vinyl Alcohol ◽  
Release Kinetic ◽  
Phenytoin Sodium ◽  
20 Nm

The objective of this study was to introduce an electrospun hybrid fibrous mat (a dual-fiber drug delivery system) based on cellulose acetate and poly(vinyl alcohol) containing tetracycline hydrochloride and phenytoin sodium, respectively. Characterization of samples was carried by morphology, drug release, cell cytotoxicity, adhesion, antibacterial property, and wettability investigations. The results showed a uniform shape and a narrow diameter distribution of fibers (between 160 ± 20 nm) for fabricated cellulose acetate/poly(vinyl alcohol) hybrid fibrous mat. The tetracycline hydrochloride release from cellulose acetate significantly decreased due to gel formation of poly(vinyl alcohol) in aqueous media. The best fit for drug release kinetic of hybrid sample was Higuchi model. Sample with tetracycline hydrochloride and phenytoin sodium drugs showed improved cell growth, viability, and antibacterial activity against Escherichia coli (~89%) and Staphylococcus aureus (~98%) in comparison with sample without drugs. The hydrophilic property of cellulose acetate/poly(vinyl alcohol) fibrous sample containing the drugs was also remarkable (~45°). To consider the obtained results, the presented hybrid fibrous mat shows a high potent for biomedical applications.

scholarly journals Adsorption and Release of Rose Bengal on Layer-by-Layer Films of Poly(Vinyl Alcohol) and Poly(Amidoamine) Dendrimers Bearing 4-Carboxyphenylboronic Acid

Polymers ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1854 ◽  
Author(s):  
Kentaro Yoshida ◽  
Akane Yamaguchi ◽  
Hiroki Midorikawa ◽  
Toshio Kamijo ◽  
Tetsuya Ono ◽  
...  
Keyword(s):  
Rose Bengal ◽  
Boronic Acid ◽  
Vinyl Alcohol ◽  
Acidic Solution ◽  
Phenylboronic Acid ◽  
Poly Vinyl Alcohol ◽  
Basic Solution ◽  
Layer By Layer ◽  
Lbl Films ◽  
H2o2 Solution

Phenylboronic acid-bearing polyamidoamine dendrimer (PBA-PAMAM)/poly(vinyl alcohol) (PVA) multilayer films were prepared through the layer-by-layer (LbL) deposition of PBA-PAMAM solution and PVA solution. PBA-PAMAM/PVA films were constructed successfully through the formation of boronate ester bonds between the boronic acid moiety in PBA and 1,3-diol units in PVA. When the (PBA-PAMAM/PVA)5 films were immersed in rose bengal (RB) solution, RB was adsorbed onto the LbL films. The amount of RB adsorbed was higher in the LbL films immersed in acidic solution than in basic solution. The release of RB from the LbL films was also promoted in the basic solution, while it was suppressed in the acidic solution. The boronic acid ester is oxidized to phenol by hydrogen peroxide (H2O2) and the carbon-boron bond is cleaved, so that the (PBA-PAMAM/PVA)5 films can be decomposed by immersion in H2O2 solution. Therefore, when RB-adsorbed (PBA-PAMAM/PVA)5 films were immersed in H2O2 solution, the release of RB was moderately promoted when the solution was weakly acidic.

scholarly journals ZrO2-TiO2 Incorporated PVDF Dual-Layer Hollow Fiber Membrane for Oily Wastewater Treatment: Effect of Air Gap

Membranes ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 124 ◽  
Author(s):  
Nurshahnawal Yaacob ◽  
Pei Sean Goh ◽  
Ahmad Fauzi Ismail ◽  
Noor Aina Mohd Nazri ◽  
Be Cheer Ng ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Uniform Distribution ◽  
Tio2 Nanoparticles ◽  
Hollow Fiber ◽  
Outer Layer ◽  
Hollow Fiber Membrane ◽  
Air Gap ◽  
Separation Performance ◽  
Oily Wastewater ◽  
Oily Wastewater Treatment

Dual-layer hollow fiber (DLHF) nanocomposite membrane prepared by co-extrusion technique allows a uniform distribution of nanoparticles within the membrane outer layer to enhance the membrane performance. The effects of spinning parameters especially the air gap on the physico-chemical properties of ZrO2-TiO2 nanoparticles incorporated PVDF DLHF membranes for oily wastewater treatment have been investigated in this study. The zeta potential of the nanoparticles was measured to be around –16.5 mV. FESEM–EDX verified the uniform distribution of Ti, Zr, and O elements throughout the nanoparticle sample and the TEM images showed an average nanoparticles grain size of ~12 nm. Meanwhile, the size distribution intensity was around 716 nm. A lower air gap was found to suppress the macrovoid growth which resulted in the formation of thin outer layer incorporated with nanoparticles. The improvement in the separation performance of PVDF DLHF membranes embedded with ZrO2-TiO2 nanoparticles by about 5.7% in comparison to the neat membrane disclosed that the incorporation of ZrO2-TiO2 nanoparticles make them potentially useful for oily wastewater treatment.

Improvement of CO2 Separation Performance by Blended Aqueous Solutions of DEA+AMP in Hollow Fiber Membrane Contactor (HFMC)

2012 ◽  
Vol 512-515 ◽  
pp. 2308-2316 ◽  
Author(s):  
Zhen Wang ◽  
Meng Xiang Fang ◽  
Shui Ping Yan ◽  
Yi Li Pang ◽  
Zhong Yang Luo
Keyword(s):  
Hollow Fiber ◽  
Hollow Fiber Membrane ◽  
Co2 Flux ◽  
Positive Influence ◽  
Separation Performance ◽  
Co2 Absorption ◽  
Membrane Contactor ◽  
Fiber Membrane ◽  
High Concentration ◽  
Carbon Dioxide Co2

Absorption of carbon dioxide (CO2) by blended diethanolamine (DEA) + 2-amino-2- methyl-1-propanol (AMP) and single DEA solvents were compared using hollow fiber membrane contactor (HFMC). Experimental results showed AMP additive has positive influence to improve CO2 absorption flux and the optimum AMP/DEA mass concentration ratio is between 0.2 and 0.4. Decreasing gas liquid ratio could greatly promote CO2 absorption, and operating temperature has weak effect on CO2 flux. Besides, large CO2 flux can be achieved with high concentration of DEA+0.2AMP solution due to the decrease of liquid phase resistance to mass transfer, but the optimal DEA concentration was recommended to be about 15% for DEA+0.2AMP solution considering the costs of amines in HFMC.

Sign in / Sign up

Export Citation Format

Share Document