Preparation and monovalent selective properties of multilayer polyelectrolyte modified cation‐exchange membranes

Deng, Huiping; Wang, Zixia; Zhang, Wei; Hu, Baisong; Zhang, Shaofeng

doi:10.1002/app.41488

Cited by 23 publications

(10 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[12][13][14][15][16] Also, the properties of multilayer films are influenced by the assembly conditions, such as the concentration, pH, ionic strength and temperature of deposition solutions. [17][18][19][20][21][22][23][24] All these parameters allowed the design of a large variety of multilayer films, which have found applications as separation membranes, 25,26 anticorrosion, and flame-retardant coatings, 27,28 antimicrobial membranes, 29,30 drug delivery systems, [31][32][33][34][35] etc.…”

Section: Introductionmentioning

confidence: 99%

Sorption/release of diclofenac sodium in/from free‐standing poly(acrylic acid)/poly(ethyleneimine) multilayer films

Ghiorghiță¹,

Bucătariu²,

Drăgan³

2016

J of Applied Polymer Sci

View full text Add to dashboard Cite

Polyelectrolyte multilayer films deposited onto various substrates have been used extensively as drug delivery systems. However, little attention has been paid to the release of drugs from free‐standing polymeric films. Herein, we report the construction of thermal crosslinked free‐standing poly(acrylic acid) (PAA)/branched poly(ethyleneimine) (PEI) multilayer films composed of 25 double layers [(PAA/PEI)25] and their use in sorption/release of diclofenac sodium (DS). The (PAA/PEI)25 multilayer films were characterized by scanning electron microscopy, potentiometric titrations and Fourier transform infrared spectroscopy, while the sorption/release of DS was monitored by UV–Vis spectroscopy. The DS sorption equilibrium data were fitted with five isotherm models (Langmuir, Freundlich, Sips, Dubinin–Radushkevich, and Temkin). The maximum equilibrium sorption capacity, qm, given by the Langmuir model was 32.42 mg DS/g. The Korsmeyer–Peppas semiempirical equation showed that the release of DS from the free‐standing (PAA/PEI)25 films proceeded by pseudo‐Fickian diffusion, irrespective of the releasing media. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43752.

show abstract

Section: Introductionmentioning

confidence: 99%

Sorption/release of diclofenac sodium in/from free‐standing poly(acrylic acid)/poly(ethyleneimine) multilayer films

Ghiorghiță¹,

Bucătariu²,

Drăgan³

2016

J of Applied Polymer Sci

View full text Add to dashboard Cite

show abstract

“…Many research efforts have employed coating of ionexchange membranes with functional multilayers to separate monovalent and divalent ions. [95][96][97][98][99][100][101][102][103][104] The selectivities of membranes with thin selective layers vary with solution ionic strength, orientation and assembly conditions of the selective layers, and operating conditions. Several studies showed that a selective coating facing the feed solution is more effective for increasing selectivity than placing such a coating at the permeate side of the membranes.…”

Section: −mentioning

confidence: 99%

Ion separations with membranes

Tang

Bruening

2020

Journal of Polymer Science

View full text Add to dashboard Cite

Ion separations are important for resource recovery, water treatment, and energy production and storage. Techniques such as chemical precipitation, selective adsorption, and solvent extraction are effective, but membranes may separate ions continuously with less waste and lower energy costs. Separation of monovalent and multivalent ions with nanofiltration or electrodialysis membranes already enables water softening and edible salt purification. Similar membranes are attractive as separators in vanadium redox flow batteries. Selective partitioning of divalent counter-ions into ion-exchange membranes even allows transport of these ions against their concentration gradients in salt mixtures. However, separations of ions with the same charge is more challenging. Recent research demonstrated highly selective ion "sieving" at small scales. Separations using electrical potentials and differences in ion electrophoretic mobilities are promising, but relatively unexplored. Carrier-mediated transport affords high selectivity in liquid membranes, but these systems are not very stable, and selective transport via hopping between anchored carriers has proven elusive. Finally, this paper discusses how concentration polarization decreases selectivities in many membrane processes. Although development of selective, inexpensive ion-separation membranes is a work in progress, successes in water softening and edible salt purification suggests that future selective membranes will serve as complementary methods to traditional purification techniques.

show abstract

“…Layer‐by‐layer deposition, by alternating deposition of polycations and polyanions on membrane, has been proven to be a low‐cost and versatile technology to fabricate membranes with monovalent selectivity. This method provides a convenient way to control both the compactness and the surface charge density of the membranes . However, all these studies concerned methods requires several steps.…”

Section: Introductionmentioning

confidence: 99%

Charge‐assisted ultrafiltration membranes for monovalent ions separation in electrodialysis

Zhu

Wang

et al. 2017

J of Applied Polymer Sci

View full text Add to dashboard Cite

Selectivity for monovalent ions is a very important feature of ion exchange membranes in view of a further expansion of the scope of electrodialysis (ED). An efficient one‐step chemical process to graft a thin polyaniline (PANI) layer on the surface and pores of an ultrafiltration (UF) membrane is reported. The existence of a PANI layer on such modified UF membrane was confirmed by Fourier transform infrared spectroscopy and scanning electron microscopy images. These membranes were extensively characterized by studying their properties such as water uptake, ion‐exchange capacity, contact angle, and performance in diffusion dialysis. ED experiments were conducted by comparing desalting of sodium chloride and magnesium chloride solutions. During the desalting procedure, the driving force has two contributions, the electrical field and the salinity‐gradient. Initially, transport of ions by the electrical field is dominant, while at the end of the experiment, diffusion dialysis by the salinity gradient plays a larger role in ion transport. The presence of PANI can hinder Mg2+ transport from the concentrate to the diluate compartment because of the electrostatic effect, while there is no obvious effect on Na+ ions. The ability of such a surface modification layer to improve the membrane selectivity for Na+/Mg2+ was confirmed by means of ED in a mixed solution. The flux of Na+ was slightly increased to 13.21 × 10−8 mol/L/min while the flux of Mg2+ was reduced to 3.32 × 10−8 mol/L/min, so that the permselectivity is almost doubled. The protonation reaction of the PANI layer creates positive charges, thus leading to an electrical repulsion barrier, which may reduce the penetration of divalent cations with respect to monovalent ions. Polyacrylonitrile‐based UF membranes with different molecular cutoff was used to determine the influence of the permselectivity. Results showed that the membrane permselectivity of smaller molecular cutoff UF membranes is higher. It can be concluded that this method is suitable for preparing membranes based on UF membranes for efficient separation of monovalent ions by electro‐driven separation techniques. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45692.

show abstract

Preparation and monovalent selective properties of multilayer polyelectrolyte modified cation‐exchange membranes

Cited by 23 publications

References 33 publications

Sorption/release of diclofenac sodium in/from free‐standing poly(acrylic acid)/poly(ethyleneimine) multilayer films

Sorption/release of diclofenac sodium in/from free‐standing poly(acrylic acid)/poly(ethyleneimine) multilayer films

Ion separations with membranes

Charge‐assisted ultrafiltration membranes for monovalent ions separation in electrodialysis

Contact Info

Product

Resources

About