Special Issue "Polyelectrolytes 2014"
A special issue of Polymers (ISSN 2073-4360).
Deadline for manuscript submissions: closed (31 March 2014)
Dr. Christian Seidel
Max Planck Institute of Colloids and Interfaces, Department of Theory & Bio-Systems, Science Park Golm, D-14424 Potsdam, Germany
Phone: +49 331 567 9608
Fax: +49 331 567 9612
Interests: polymers and polyelectrolytes in solution and at interfaces; polyelectrolyte brushes; organization of nanoparticles at copolymer brushes; numerical simulations and theory
Synthetic and natural polyelectrolytes have been the subject of fundamental and applied studies for nearly a century. Due to substantial advances both in experimental methods and theoretical approaches, since the 1990’s polyelectrolyte research has undergone a considerable speed-up. On the one hand, interest in polyelectrolytes is spurred by their fascinating properties, such as water solubility, intra- and interchain interactions, the strength of which can be tuned simply by varying salt concentration, and ionic conductivity. These properties make polyelectrolytes attractive from the application-oriented point of view, such as stabilizer of colloidal suspensions, additives to modify flocculation and viscosity, and superabsorbers. Functional polyelectrolytes combine the useful properties intrinsic to polyelectrolytes with added functionality provided by specific features of the polymer backbone, such as delocalized electrons in conjugated chains. Combined functionality can be used to create materials with highly interesting optical, electro-optical, and electronic properties.
On the other hand, the understanding of polyelectrolytes still belongs to the most challenging and most exciting problems in polymer physics and physical chemistry. Despite much effort and substantial progress during the last two decades, much more work is ahead to achieve a quantitative agreement between theory and experiments for a lot of problems, such as counterion condensation, chain stiffness, and formation of complexes. It is still a major open problem to have a satisfactory model explaining the coupling between small ions in solutions and polyelectrolyte charges, which is necessary to understand how electrostatics affects the behavior of polyelectrolytes.
Many biologically relevant macromolecules, such as nucleic acids, polypeptides, and polysaccharides, are polyelectrolytes. Electrophoresis is a well-established method for the fractionation of polyelectrolytes and more specifically, DNA. Hydration-mediated interactions play an important role in the field of biological polyelectrolytes, but are not well understood on nano-scales.
Dr. Christian Seidel
Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.
Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed Open Access monthly journal published by MDPI.
- synthesis and biopolyelectrolytes
- stimuli-responsive polyelectrolytes
- hydration effects and ion-specific interactions
- polyelectrolyte multilayers, complexes and gels
- polyelectrolyte brushes
- conjugated polyelectrolytes
- theory and modeling
Article: Lipid Monolayers with Adsorbed Oppositely Charged Polyelectrolytes: Influence of Reduced Charge Densities
Polymers 2014, 6(7), 1999-2017; doi:10.3390/polym6071999
Received: 30 April 2014; in revised form: 26 June 2014 / Accepted: 27 June 2014 / Published: 10 July 2014| PDF Full-text (801 KB) | HTML Full-text | XML Full-text
Polymers 2014, 6(7), 1897-1913; doi:10.3390/polym6071897
Received: 21 March 2014; in revised form: 24 June 2014 / Accepted: 26 June 2014 / Published: 4 July 2014| PDF Full-text (1079 KB) | HTML Full-text | XML Full-text | Supplementary Files
Article: Stimuli-Responsive Polyelectrolyte Brushes As a Matrix for the Attachment of Gold Nanoparticles: The Effect of Brush Thickness on Particle Distribution
Polymers 2014, 6(7), 1877-1896; doi:10.3390/polym6071877
Received: 16 April 2014; in revised form: 23 June 2014 / Accepted: 24 June 2014 / Published: 27 June 2014| PDF Full-text (1259 KB) | Supplementary Files
Polymers 2014, 6(6), 1756-1772; doi:10.3390/polym6061756
Received: 5 May 2014; in revised form: 3 June 2014 / Accepted: 4 June 2014 / Published: 16 June 2014| PDF Full-text (1785 KB) | HTML Full-text | XML Full-text
Polymers 2014, 6(6), 1655-1675; doi:10.3390/polym6061655
Received: 15 April 2014; in revised form: 15 May 2014 / Accepted: 18 May 2014 / Published: 30 May 2014| PDF Full-text (815 KB) | HTML Full-text | XML Full-text | Supplementary Files
Article: Development of a Biocompatible Layer-by-Layer Film System Using Aptamer Technology for Smart Material Applications
Polymers 2014, 6(5), 1631-1654; doi:10.3390/polym6051631
Received: 17 March 2014; in revised form: 4 May 2014 / Accepted: 8 May 2014 / Published: 23 May 2014| PDF Full-text (2854 KB) | HTML Full-text | XML Full-text | Supplementary Files
Polymers 2014, 6(5), 1602-1617; doi:10.3390/polym6051602
Received: 31 March 2014; in revised form: 13 May 2014 / Accepted: 19 May 2014 / Published: 23 May 2014| PDF Full-text (1089 KB) | HTML Full-text | XML Full-text
Polymers 2014, 6(5), 1544-1601; doi:10.3390/polym6051544
Received: 16 April 2014; in revised form: 3 May 2014 / Accepted: 8 May 2014 / Published: 23 May 2014| PDF Full-text (463 KB) | HTML Full-text | XML Full-text
Article: pH and Salt Effects on the Associative Phase Separation of Oppositely Charged Polyelectrolytes
Polymers 2014, 6(5), 1414-1436; doi:10.3390/polym6051414
Received: 27 March 2014; in revised form: 9 May 2014 / Accepted: 9 May 2014 / Published: 16 May 2014| PDF Full-text (3356 KB) | HTML Full-text | XML Full-text
Review: Does Electrical Conductivity of Linear Polyelectrolytes in Aqueous Solutions Follow the Dynamic Scaling Laws? A Critical Review and a Summary of the Key Relations
Polymers 2014, 6(4), 1207-1231; doi:10.3390/polym6041207
Received: 14 February 2014; in revised form: 4 April 2014 / Accepted: 11 April 2014 / Published: 22 April 2014| PDF Full-text (660 KB) | HTML Full-text | XML Full-text
The below list represents only planned manuscripts. Some of these manuscripts have not been received by the Editorial Office yet. Papers submitted to MDPI journals are subject to peer-review.
Type of Paper: Article
Title: pH and Salt Effects on the Associative Phase Separation of Oppositely Charged Polyelectrolytes
Authors: Prateek Jha and Ronald G. Larson
Affiliation: Department of Chemical Engineering, The University of Michigan, Ann Arbor, MI 48109, USA
Abstract: We develop a thermodynamic description of the associative phase separation observed in aqueous solutions of oppositely charged polyelectrolytes. The theory is applied to study the effects of pH and salt concentration on the phase separation regime and compared with available experimental data. Results indicate the existence of a critical salt concentration below which the mixture phase separates; magnitude of this critical salt concentration increases with increase in the degree of dissociation of polyelectrolytes. pH variations gives rise to disparity between the degree of dissociation of the two polyelectrolytes, resulting in asymmetry in their binodal compositions. Effects of differences in the hydrophobicity of polyelectrolytes are also investigated. We conclude with a discussion of possible correlations between the results of this study and the layer-by-layer assembly of polyelectrolytes.
Type of Paper: Article
Title: Electrostatic Self-Assembly of Polymers and Colloids: New Routes to New Functional Materials
Author: Matthew Tirrell
Affiliation: Institute for Molecular Engineering, University of Chicago, 5747 South Ellis Avenue, Jones 222, Chicago, Illinois 60637, USA; E-Mail: firstname.lastname@example.org
Abstract: Highly charged polymer chains in monovalent salt media exhibit a fairly simple range of behaviors, swelling in low salt, shrinking in high salt, based on the screening of repulsive electrostatic interactions among the segments. In the presence of multivalent constituents, attractive forces arise between polyelectrolyte chains. These attractions produce strong collapse of polyelectrolyte chains, adhesion between polyelectrolyte bearing surfaces, precipitation, and in the case of mixtures of oppositely charged polyelectrolytes, formation of fluid complex coacervate phases. Such polyelectrolyte complexes have very low interfacial tension with water, and so engulf particles, invade porous media and spread on surfaces. Inorganic syntheses can produce nanoparticles in situ. Multicomponent polymers with polyelectrolyte blocks can self-assembly in novel ways producing new ordered, hydrogel materials that can be the basis for new materials from biomedicine to tough composites.
Type of Paper: Article
Title: Electrophoresis of Polyelectrolytes in Confinement: The Influence of Counterion Properties
Authors: Sorin Nedelcu and Jens-Uwe Sommer
Affiliation: Institute of Physical Chemistry and Polymer Physics, Leibniz-Institut für Polymerforschung Dresden e. V., Werkstofflaborgebäude, Budapester Straße 29, 01069 Dresden, Germany; E-Mail: email@example.com
Type of Paper: Article
Title: Stimuli-Responsive Polymer Brushes as a Matrix for Attachment of Gold Nanoparticles. (1) Effect of Brush Thickness on Particle Distribution
Authors: Stephanie Christau, Stefan Thurandt, Zuleyha Yenice and Regine von Klitzing *
Affiliation: Stranski-Laboratorium für Physikalische Chemie, Technische Universität Berlin, Straße des 17. Juni 124, 10623 Berlin, Germany; E-mail: firstname.lastname@example.org
Abstract: The effect of brush thickness on the loading of gold nanoparticles (AuNPs) within stimuli-responsive poly-(N,N-(dimethylamino ethyl) methacrylate) (PDMAEMA) polyelectrolyte brushes is reported. AuNPs of 13 nm diameter were succesfully attached to give PDMAEMA/AuNP-13 hybrids. ATRP was used to grow polymer brushes via a ‘grafting from’ approach from a 2-bromo-2-methyl-N-(3-(triethoxysilyl)propyl) propanamide (BTPAm)-covered silicon substrate. The brush thickness was tuned by varying the polymerization time. Using a new type of self-made sealed reactor, thick brushes were synthesized and a systematic study by varying a single parameter, the brush thickness, while keeping all other parameters constant, was performed. X-ray reflectivity, electron scanning microscopy and ellipsometry were used to study the particle loading, particle distribution and interpenetration of the particles within the brush matrix. For the first time based on experimental results, the particle distribution within a polyelectrolyte brush is reported. A model for the structure of the hybrid was elaborated and verified by the mentioned techniques. Additionally, it could be shown that the particle number density and the optical properties of the brush/particle hybrid change as a function of the brush thickness.
Type of Paper: Review
Title: Structures and Synthesis Of Zwitterionic Polymers
Author: André Laschewsky *
Affiliation: Fraunhofer Institute of Applied Polymer Research IAP, Geiselbergstr.69, 14476 Potsdam-Golm, Germany; E-mail: email@example.com
Abstract: The structures and synthesis of polyzwitterions ("polybetaines") are reviewed, emphasizing the literature of the past decade. Particular attention is given to the general challenges faced, and to successful strategies to obtain polymers with a true balance of permanent cationic and anionic groups, thus resulting in an overall zero charge. Also, the progress due to applying new methodologies from general polymer synthesis, such as controlled polymerization methods or the use of "click" chemical reactions is presented. Furthermore, the emerging topic of responsive ("smart") polyzwitterions is addressed. The considerations and critical discussions are illustrated by typical examples.
Type of Paper: Article
Title: A Coarse-Grained DNA Model Parameterized from Atomistic Simulations by Inverse Monte Carlo
Authors: Nikolay Korolev, Di Luo, Alexander P. Lyubartsev and Lars Nordenskiöld *
Affiliation: School of Biological Sciences, Nanyang Technological University, Singapore; E-mail: LarsNor@ntu.edu.sg
Abstract: Computer modelling of very large biomolecular systems like long DNA polyelectrolytes or protein-DNA complex like chromatin cannot reach all-atom resolution in a foreseeable future and this necessitates the development of coarse-grained (CG) approximations. DNA is both highly charged and mechanically rigid semi-flexible polymer and adequate DNA modelling requires a correct description of both its structural stiffness and salt-dependent electrostatic forces. Here we present a novel CG model of DNA that approximates the DNA polymer as a chain of 5-bead units. Each unit represents two DNA base pairs with one central bead for bases and pentose moieties and four others for phosphate groups. Charges, intra- and inter-molecular force field potentials for the CG DNA model were calculated using the inverse Monte Carlo method from all atom molecular dynamic (MD) simulations of 22 bp DNA oligonucleotides. The CG model was tested by performing dielectric continuum Langevin MD simulations of a 200 bp double helix DNA in solutions of monovalent salt with explicit ions. Excellent agreement with experimental data was obtained for the dependence of the DNA persistent length on salt concentration in the range 0.1 – 100 mM. The new CG DNA model is suitable for modelling various biomolecular systems with adequate description of electrostatic and mechanical properties.
Type of Paper: Article
Title: Structure of Microgels with Debye-Hückel Interactions
Authors: Hideki Kobayashi and Roland G. Winkler *
Affiliation: Theoretical Soft Matter and Biophysics, Institute for Advanced Simulation, Forschungszentrum Jülich, 52425 Jülich, Germany; E-mail: firstname.lastname@example.org
Abstract: The structural properties of model microgel particles are investigated by molecular dynamics simulations applying a coarse-grained model. A microgel is comprised of a regular network of polymers internally connected by tetra-functional crosslinks and with dangling ends at its surface. The self-avoiding polymers are modeled as bead-spring linear chains. Electrostatic interactions are taken into account by the Debye-Hückel potential. The microgels exhibit a quite uniform density under bad solvent conditions with a rather sharp surface. With increasing Debye length, structural inhomogeneities appear, their surface becomes fuzzy and, at very large Debye lengths, well defined again. Similarly, the polymer conformations change from a self-avoiding walk to a rodlike behavior. Thereby, the average polymer radius of gyration follows a scaling curve in terms of polymer length and persistence length with an asymptotic rodlike behavior for swollen microgels and self-avoiding walk behavior for weakly swollen gel particles.
Type of Paper: Article
Title: Salt Effect on Osmotic Pressure of Polyelectrolytes Solutions: Simulation Study
Authors: Jan-Michael Carrillo and Andrey Dobrynin *
Affiliation: Polymer Program, Institute of Materials Science and Department of Physics, University of Connecticut, Storrs, CT 06269, USA; E-mail: email@example.com
Abstract: We present results of the hybrid Monte Carlo/molecular dynamics simulations of the osmotic pressure of salt solutions of polyelectrolytes. In our simulations we used a coarse-grained representation of polyelectrolyte chains, counterions and salt ions. During simulation runs we alternate Monte Carlo and molecular dynamics simulation steps. Monte Carlo steps were used to perform small ion exchange between simulation box containing salt ions (salt reservoir) and simulation box with polyelectrolyte chains, counterions and salt ions (polyelectrolyte solution). This allowed us to model Donnan equilibrium and partitioning of salt and counterions across membrane impermeable to polyelectrolyte chains. Our simulations have confirmed that the main contribution to the system osmotic pressure is due salt ions and osmotically active counterions. The fraction of the condensed (osmotically inactive) counterions first increases with increasing the solution ionic strength then saturates. The reduced value of the system osmotic coefficient is a universal function of the ratio of the concentration of osmotically active counterions and salt concentration in salt reservoir. Simulation results are in a very good agreement with osmotic pressure measurements in sodium polystyrene sulfonate, DNA, polyacrylic acid, sodium polyanetholesulfonic acid, polyvinylbenzoic acid, and polydiallyldimethylammonium chloride solutions.
Type of Paper: Article
Title: Development of a Biocompatible Layer-by-Layer Film System using Aptamer Technology for Smart Material Applications
Authors: Amanda Foster and Maria C. DeRosa *
Affiliation: Department of Chemistry, Carleton University, Ottawa-Carleton Chemistry Institute, 1125 Colonel By Drive, Ottawa, Ontario, K1S 5B6, Canada; E-mail: firstname.lastname@example.org
Abstract: Aptamers are short, single stranded nucleic acids that fold into well-defined 3D structures which bind to a target molecule with affinities and specificities that can rival or in some cases exceed those of antibodies. The compatibility of aptamers with nanostructures such as thin films, in combination with their affinity, selectivity, and conformational changes upon target interaction, could set the foundation for the development of novel smart materials. In this study, the development of a biocompatible aptamer-polyelectrolyte film system was investigated using a layer-by-layer approach. Using fluorescence microscopy, we demonstrated the ability of the sulforhodamine B aptamer to bind its cognate target while sequestered in a chitosan-hyaluronan film matrix. Studies using UV-Vis spectrophotometry also suggest that deposition conditions such as rinsing time and volume play a strong role in the internal film interactions and growth mechanisms of chitosan-hyalruonan films. The continued study and development of aptamer-functionalized thin films provides endless new opportunities for novel smart materials and has the potential to revolutionize the field of controlled release.
Type of Paper: Article
Title: Bone Therapeutic Drug Delivery and cell Interaction of Adhesive Polyelectrolyte Complex Particle Films
Authors: Martin Müller *, Bernhard Torger, David Vehlow, Birgit Urban, Beatrice Woltmann and Ute Hempel
Affiliation: Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Str. 6, 01069 Dresden, Germany; E-mail: email@example.com
Abstract: Herein we report on novel zoledronate (ZOL) and simvastatin (SIM) loaded polyelectrolyte complex (PEC) nanoparticles, which can be solution casted on Ge substrates serving as analytically accessible model substrate regarding bone substituting materials (BSM). Four important requirements for drug loaded PEC particles and their films are addressed herein, which are the colloidal stability of PEC dispersions (i), interfacial stability (ii), biocompatibility (iii) and release kinetics in contact to release medium (iv). Dynamic light scattering measurements (DLS) showed, that both poly(ethyleneimine)/cellulose sulphate (PEI/CS) and PEI/dextran sulphate (PEI/DS) particles could be prepared with hydrodynamic radii in the range 35-170 nm and time stability up to several months. Transmission FTIR spectroscopy evidenced that films of both systems were stable in contact to the release medium (PBS) for several days. Immunofluorescence imaging suggested cytocompatibility of cast PEC particle films. Finally, in-situ-ATR-FTIR spectroscopy at cast PEC/drug films at Ge substrates revealed retarded drug releases in comparison to the pure drug film.
Last update: 28 April 2014