scholarly journals Nanogyroids Incorporating Multivalent Lipids: Enhanced Membrane Charge Density and Pore Forming Ability for Gene Silencing

Langmuir ◽  
2011 ◽  
Vol 27 (12) ◽  
pp. 7691-7697 ◽  
Author(s):  
Cecília Leal ◽  
Kai K. Ewert ◽  
Rahau S. Shirazi ◽  
Nathan F. Bouxsein ◽  
Cyrus R. Safinya
Keyword(s):  
Gene Silencing ◽  
Charge Density ◽  
Membrane Charge

scholarly journals Anomalous Thermo-osmotic Conversion Performance of Ionic Covalent-Organic-Framework Membranes in Response to Charge Variations

2022 ◽  
Author(s):  
Qi Sun ◽  
Weipeng Xian ◽  
Xiuhui Zuo ◽  
Changjia Zhu ◽  
Qing Guo ◽  
...  
Keyword(s):  
Charge Density ◽  
Energy Conversion ◽  
Energy Demand ◽  
High Performance ◽  
Critical Factor ◽  
Energy Conversion Efficiency ◽  
Nanoporous Membranes ◽  
Power Extraction ◽  
Membrane Charge ◽  
Salinity Difference

Abstract The development of efficient thermo-osmotic energy conversion devices has fascinated scientists and engineers for several decades in terms of satisfying the growing energy demand. The fabrication of ionic membranes with a high charge population is known to be a critical factor in the design of high-performance power generators for achieving high permselectivity and, consequently, high power extraction efficiency. Herein, we experimentally demonstrated that the thermo-osmotic energy conversion efficiency was improved by increasing the membrane charge density; however, this enhancement occurred only within a narrow window and subsequently exhibited a plateau over a threshold density. The complex interplay between pore−pore interactions and fluid structuration for ion transport across the upscaled nanoporous membranes helped explain the obtained results with the aid of numerical simulations. Consequently, the power generation efficiency of the multipore membrane deteriorated, deviating considerably from the case of simple linear extrapolation of the behavior of the single-pore counterparts. A plateau in the output electric power was observed at a moderate charge density, affording a value of 210 W m−2 at a 50-fold salinity difference with a temperature gradient of 40 K. This study has far-reaching implications for discerning an optimal range of membrane charge populations for augmenting the energy extraction, rather than intuitively focusing on achieving high densities.

Enhanced Transfection Efficiency of Multicomponent Lipoplexes in the Regime of Optimal Membrane Charge Density

2008 ◽  
Vol 112 (36) ◽  
pp. 11298-11304 ◽  
Author(s):  
Giulio Caracciolo ◽  
Daniela Pozzi ◽  
Ruggero Caminiti ◽  
Cristina Marchini ◽  
Maura Montani ◽  
...  
Keyword(s):  
Charge Density ◽  
Transfection Efficiency ◽  
Membrane Charge

scholarly journals Zeta Potential, Effective Membrane Charge and Donnan Potential for TiO2 NF Ceramic Membrane

2018 ◽  
Vol 24 (9) ◽  
pp. 21 ◽  
Author(s):  
Ahmed Faiq Hassan Al-Alawy ◽  
Amer Naji Ahmed Al-Naemi ◽  
Mudhaffar Yacoub Hussein
Keyword(s):  
Zeta Potential ◽  
Charge Density ◽  
Surface Charge ◽  
Isoelectric Point ◽  
Pore Radius ◽  
Ceramic Membrane ◽  
Effective Thickness ◽  
Donnan Potential ◽  
Membrane Charge ◽  
Effective Pore Radius

Nanofiltration (NF) ceramic membrane have found increasing applications particularly in wastewater and water treatment. In order to estimate and optimize the performance of NF membranes, the membrane should be characterized correctly in terms of their basic parameters such as effective pore radius (rp) and equivalent effective thickness as well as effective surface charge ( ), the effective charge density ( ) and Donnan potential ( ). The impact of electrokinetic (zeta) potential on the membrane surface charge density, effective membrane charge density and Donnan potential at two different concentrations of the reference solutions 0.001, 0.01 M sodium chloride at various pH values from 3 to 9, and effective pore radius (rp) for nominal 0.9 nm  ceramic TiO2 NF membrane were evaluated. Experiments were conducted at cross flow (1.0 m/s) using Microelectrophoresis technique for measuring membrane zeta potential, effective pore radius, and Donnan steric pore model (DSPM). The TiO2 membrane isoelectric point (net membrane charge equals zero) was found at pH of 3.7, 3.5 for 0.001 and 0.01 M NaCl respectively. The results showed that the NF membrane zeta potential changes its sign from positive to negative after the isoelectric point. The evaluated effective pore radius was found to be equal to 0.56 nm by using (DSPM) and the membrane equivalent effective thickness equals to (2×10-6 m).  

Theoretical Analysis on Interacting Effect of Steric and Donnan Factors in Nanofiltration Membrane Separation System

2012 ◽  
Author(s):  
Nora’aini Ali ◽  
A. Wahab Mohammad
Keyword(s):  
Charge Density ◽  
Pore Size ◽  
Effective Charge ◽  
Interactive Effect ◽  
Planck Equation ◽  
Separation Performance ◽  
Nanofiltration Membranes ◽  
Membrane Pore ◽  
Membrane Charge ◽  
Membrane Pore Size

Prestasi pemisahan sistem membran penuras nano didapati sangat bergantung kepada kesan sterik dan cas. Kajian terdahulu telah menunjukkan bahawa kombinasi yang tepat di antara saiz liang (kesan sterik) dan ketumpatan cas berkesannya (kesan Donnan) akan memberikan prestasi pemisahan yang optimum. Justeru itu, keupayaan menghasilkan membran penuras nano bersifat optimum akan memberikan pembaikan yang signifikan dari aspek prestasi membran dan pengurangan kos pemprosesan. Oleh itu, objektif utama kajian teoritikal ini ialah untuk menyelidik kesan interaktif saiz liang (rp) dan ketumpatan cas membran, (Xd) terhadap prestasi pemisahan. Dua parameter tanpa dimensi telah digunakan iaitu λ (λ = rs/rp) dan ζ(ζ = Xd/Cb). Pengangkutan elektrolit melalui membran penuras nano tersebut ditentukan dengan menggunakan model liang sterik-donnan (DSPM). Pelbagai larutan garam dengan pelbagai saiz liang dan kesan cas diuji dengan menggunakan model tersebut. Kajian menunjukkan bahawa untuk kes membran dengan kapasiti cas berkesan yang tinggi, faktor Donnan didapati lebih penting untuk membran yang longgar strukturnya. Sumbangan faktor Donnan ini berkurangan dengan peningkatan saiz liang membran. Sebaliknya, untuk membran berketumpatan cas yang rendah, kesan faktor Donnan terhadap tolakan ion boleh diabaikan, tanpa bergantung kepada saiz liang. Kata kunci: Penurasan nano, DSPM, ketumpatan caj berkesan, saiz liang, teoritikal The separation performance of NF membrane system is found to be significantly dependent on the steric and charge effects. Previous studies have shown that the right combination of membrane pore size (steric effect) and its effective charge density (donnan effect) will lead to an optimum separation performance. Hence, the ability to produce nanofiltration membranes with optimized properties will certainly provide significant improvement in terms of membrane performance and processing cost reduction. Therefore, the main objective of this theoretical study is to investigate the interactive effect of membrane pore size (rp) and membrane charge density, (Xd) towards the separation performance. Two general dimensionless parameters were used namely λ (λ = rs/rp) and ζ(ζ = Xd/Cb). The electrolyte transport through nanofiltration membranes is determined using a model based on the application of the extended Nernst–Planck equation coupled with Donnan–steric pore model (DSPM). A variety of salt solution with various pore size and charge effect was tested using the above–mentioned model. It was found that for the case of membranes with high effective charge density, the Donnan factor is more prominent for loose membranes. The contribution of the factor decreased with the increase of membrane pore size. Vice versa, for the lower charge density membrane, the effect of Donnan factor towards ion rejection could be neglected, regardless of membrane pore sizes. Key words: Nanofiltration, DSPM, membrane charge density, pore size, theoretical

Effect of membrane charge density on the protein corona of cationic liposomes: Interplay between cationic charge and surface area

2011 ◽  
Vol 99 (3) ◽  
pp. 033702 ◽  
Author(s):  
Giulio Caracciolo ◽  
Daniela Pozzi ◽  
Sofia Candeloro De Sanctis ◽  
Anna Laura Capriotti ◽  
Giuseppe Caruso ◽  
...  
Keyword(s):  
Charge Density ◽  
Surface Area ◽  
Protein Corona ◽  
Cationic Liposomes ◽  
Membrane Charge

Supramolecular Organization in Self-Assembly of Chromatin and Cationic Lipid Bilayers is Controlled by Membrane Charge Density

2012 ◽  
Vol 13 (12) ◽  
pp. 4146-4157 ◽  
Author(s):  
Nikolay V. Berezhnoy ◽  
Dan Lundberg ◽  
Nikolay Korolev ◽  
Chenning Lu ◽  
Jiang Yan ◽  
...  
Keyword(s):  
Charge Density ◽  
Lipid Bilayers ◽  
Self Assembly ◽  
Cationic Lipid ◽  
Supramolecular Organization ◽  
Membrane Charge
Sign in / Sign up

Export Citation Format

Share Document