Understanding membrane selectivity in pervaporation of water-rich water:ethanol mixtures

2018 ◽  
Vol 96 (8) ◽  
pp. 1780-1788 ◽  
Author(s):  
Rowan P. Prangley ◽  
Andrew D. Wallace ◽  
Trevor C. Brown ◽  
Christopher M. Fellows
Keyword(s):  
Membrane Selectivity

Low-Resistance Monovalent-Selective Cation Exchange Membranes for Energy-Efficient Ion Separations

2020 ◽  
Author(s):  
Eyal Wormser ◽  
Oded Nir ◽  
Eran Edri
Keyword(s):  
Cation Exchange ◽  
Brackish Water ◽  
Molecular Layer ◽  
Water Desalination ◽  
Molecular Layer Deposition ◽  
Selective Layer ◽  
Trade Off ◽  
Membrane Selectivity ◽  
Layer Deposition ◽  
Water Energy Nexus

<div> <div> <div> <p>The desalination of brackish water provides water to tens of millions of people around the world, but current technologies deplete much needed nutrients from the water, which is detrimental to both public health and agriculture. A selective method for brackish water desalination, which retains the needed nutrients, is electrodialysis (ED) using monovalent-selective cation exchange membranes (MVS-CEMs). However, due to the trade-off between membrane selectivity and resistance, most MVS-CEMs demonstrate either high transport resistance or low selectivity, which increase energy consumption and hinder the use of such membranes for brackish water desalination by ED. Here, we used molecular layer deposition (MLD) to uniformly coat CEMs with ultrathin layers of alucone. The positive surface charge of the alucone instills monovalent selectivity in the CEM. Using MLD enabled us to precisely control and minimize the selective layer thickness, while the flexibility and nanoporosity of the alucone prevent cracking and delamination. Under conditions simulating brackish water desalination, this compound provides monovalent selectivity with negligible added resistance—the smallest reported resistance for a monovalent-selective layer, to date—thereby alleviating the selectivity–resistance trade-off. Addressing the water–energy nexus, we show that using these membranes in ED will cut at least half of the energy required for selective brackish water desalination with current MVS-CEMs. </p> </div> </div> </div>

scholarly journals Electrochemotherapy Effectiveness Loss due to Electric Field Indentation between Needle Electrodes: A Numerical Study

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
José Alvim Berkenbrock ◽  
Rafaela Grecco Machado ◽  
Daniela Ota Hisayasu Suzuki
Keyword(s):  
Electric Field ◽  
In Silico ◽  
Treatment Effectiveness ◽  
Numerical Study ◽  
Specific Treatment ◽  
The Body ◽  
Membrane Selectivity ◽  
Chemotherapy Drugs ◽  
Mast Cell Tumor ◽  
Anticancer Treatment

Electrochemotherapy is an anticancer treatment based on applying electric field pulses that reduce cell membrane selectivity, allowing chemotherapy drugs to enter the cells. In parallel to electrochemotherapy clinical tests, in silico experiments have helped scientists and clinicians to understand the electric field distribution through anatomically complex regions of the body. In particular, these in silico experiments allow clinicians to predict problems that may arise in treatment effectiveness. The current work presents a metastatic case of a mast cell tumor in a dog. In this specific treatment planning study, we show that using needle electrodes has a possible pitfall. The macroscopic consequence of the electroporation was assessed through a mathematical model of tissue electrical conductivity. Considering the electrical and geometrical characteristics of the case under study, we modeled an ellipsoidal tumor. Initial simulations were based on the European Standard Operating Procedures for electrochemotherapy suggestions, and then different electrodes’ arrangements were evaluated. To avoid blind spots, multiple applications are usually required for large tumors, demanding electrode repositioning. An effective treatment electroporates all the tumor cells. Partially and slightly overlapping the areas increases the session’s duration but also likely increases the treatment’s effectiveness. It is worth noting that for a single application, the needles should not be placed close to the tumor’s borders because effectiveness is highly likely to be lost.

scholarly journals Acid-Resistance Enhancement of Thin-Film Composite Membrane Using Barrier Effect of Graphene Oxide Nanosheets

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3151
Author(s):  
Hee-Ro Chae ◽  
In-Chul Kim ◽  
Young-Nam Kwon
Keyword(s):  
Thin Film ◽  
Graphene Oxide ◽  
Acid Resistance ◽  
Barrier Effect ◽  
Graphene Oxide Nanosheets ◽  
Film Composite ◽  
Membrane Selectivity ◽  
Thin Film Composite ◽  
Acid Reaction ◽  
Walled Carbon Nanotubes

In this study, the effect of graphene oxide nanosheets (GONs) embedded in a thin-film composite (TFC) polyamide (PA) membrane on the acid resistance of the membrane was investigated by comparison with the effect of oxidized single-walled carbon nanotubes (o-SWNTs). Both GONs and o-SWNTs increased the hydrophilicity of the membranes and caused the formation of ridges and clustered bumps on the surfaces, resulting in slightly improved water permeability. However, the o-SWNTs-embedded membrane did not show a difference in acid resistance depending on the concentration of embedded material, but the acid resistance of the GONs-embedded membrane increased with increasing concentration. The acid resistance of the GONs-embedded membranes appears to be mainly due to the barrier effect caused by the nanosheet shape of the GONs along with a sacrificial role of the PA layer protruded by the addition of GONs and the decrease of acid reaction sites by the hydrogen bonding between GONs and PA. When the TFC PA membrane was prepared with a high amount (300 ppm) of the GONs without considering aggregation of GONs, membrane selectivity exceeding 95% was maintained 4.7 times longer than the control TFC membrane. This study shows that the acid resistance can be enhanced by the use of GONs, which give a barrier effect to the membrane.

Influence of membrane selectivity on helium recovery from natural gas

2016 ◽  
Vol 56 (4) ◽  
pp. 344-348 ◽  
Author(s):  
N. I. Laguntsov ◽  
I. M. Kurchatov ◽  
M. D. Karaseva ◽  
V. I. Solomakhin ◽  
P. A. Churkin
Keyword(s):  
Natural Gas ◽  
Membrane Selectivity

scholarly journals Influence of N-acylation of a peptide derived from human lactoferricin on membrane selectivity

2006 ◽  
Vol 1758 (9) ◽  
pp. 1426-1435 ◽  
Author(s):  
Dagmar Zweytick ◽  
Georg Pabst ◽  
Peter M. Abuja ◽  
Alexander Jilek ◽  
Sylvie E. Blondelle ◽  
...  
Keyword(s):  
Membrane Selectivity

Mathematical Modeling Of An Amperometric Glucose Sensor: The Effect Of Membrane Permeability And Selectivity On Performance

2012 ◽  
Author(s):  
Azila Abd. Aziz
Keyword(s):  
Mathematical Modeling ◽  
Transport Properties ◽  
Membrane Permeability ◽  
Glucose Sensor ◽  
Digital Simulation ◽  
Glucose Biosensor ◽  
Glucose Biosensors ◽  
Interference Reduction ◽  
Membrane Selectivity ◽  
Selective Membrane

Gangguan dari bahan kimia elektro–aktif seperti asid askorbik, asid urik dan asetaminofen adalah merupakan satu masalah bagi biosensor glukosa berasaskan peroksid. Kebanyakan kerja penyelidikan memfokuskan kepada penggunaan membran yang perm–selektif di antara elektrod dan komponen aktif sensor untuk menghilangkan masalah ini. Dalam kerja penyelidikan ini, satu model matematik telah dibina untuk mengkaji kesan kebolehtelapan dan kememilihan bagi prestasi biosensor glukosa berasaskan peroksid. Simulasi digital telah dijalankan menggunakan kaedah pembezaan terhingga. Seperti yang dijangka, kememilihan membran kepada peroksid memainkan peranan besar dalam mengurangkan gangguan. Namun begitu, model juga mencadangkan yang manipulasi sifat pengangkutan lapisan pelindung luar boleh juga menghasilkan keputusan yang memberangsangkan dalam mengurangkan gangguan. Kata kunci: Biosensor glukosa; model matematik; asetaminofen; pengganggu; sifat pengangkutan Interference from electro–active chemicals such as ascorbic acid, uric acid and acetaminophen can be a problem for peroxide based glucose biosensors. Most works focused on the employment of a perm–selective membrane sandwiched between the electrode and the active component of the sensor to overcome this problem. In this work, a mathematical model has been developed to study the effect of membrane permeability and selectivity on peroxide based glucose biosensor performance. Digital simulation was carried out using the finite difference method. As expected, membrane selectivity to peroxide played a major role in interference reduction. However, interestingly, the model also suggested that the manipulation of the transport properties of the protective outer layer would also result in acceptable interference reduction. Key words: Glucose biosensors; mathematical modeling; acetaminophen; interferents; transport properties

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