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Polymers, Volume 6, Issue 5 (May 2014), Pages 1251-1654

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Research

Jump to: Review

Open AccessArticle Behavior of FRP-Confined Concrete-Filled Steel Tube Columns
Polymers 2014, 6(5), 1333-1349; doi:10.3390/polym6051333
Received: 30 March 2014 / Revised: 1 May 2014 / Accepted: 5 May 2014 / Published: 8 May 2014
Cited by 2 | PDF Full-text (1432 KB) | HTML Full-text | XML Full-text
Abstract
This paper presents the results of an experimental study into the behavior of concrete-filled steel tube columns confined by fiber-reinforced polymer (FRP). Eleven columns were tested to investigate the effects of the FRP layer number, the thickness of the steel tube and concrete
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This paper presents the results of an experimental study into the behavior of concrete-filled steel tube columns confined by fiber-reinforced polymer (FRP). Eleven columns were tested to investigate the effects of the FRP layer number, the thickness of the steel tube and concrete strength on their load capacity and axial deformation capacity. The experimental results indicated that the FRP wrap can effectively confine the concrete expansion and delay the local buckling of the steel tube. Both the load capacity and the axial deformation capacity of concrete-filled steel tube columns can be substantially enhanced with FRP confinement. A model is proposed to predict the load capacity of the FRP-confined concrete-filled steel tube columns. The predicted results are generally in good agreement with the experimental ones obtained in this study and in the literature. Full article
(This article belongs to the Special Issue Fiber-Reinforced Polymer Composites in Structural Engineering)
Open AccessArticle Optimization of Biopolymer Based Transdermal Films of Metoclopramide as an Alternative Delivery Approach
Polymers 2014, 6(5), 1350-1365; doi:10.3390/polym6051350
Received: 27 January 2014 / Revised: 29 April 2014 / Accepted: 30 April 2014 / Published: 9 May 2014
Cited by 6 | PDF Full-text (484 KB) | HTML Full-text | XML Full-text
Abstract
The objectives of this study were to develop and to characterize sodium alginate based matrix-type transdermal films of metoclopramide hydrochloride (MTC) in order to improve patient compliance to treatment. The suitability of sodium alginate was shown to be a natural film former in
[...] Read more.
The objectives of this study were to develop and to characterize sodium alginate based matrix-type transdermal films of metoclopramide hydrochloride (MTC) in order to improve patient compliance to treatment. The suitability of sodium alginate was shown to be a natural film former in terms of the physicochemical, mechanical, and bioadhesive features of the MTC loaded transdermal films. Terpinolene provided the highest drug release among the different terpenes (nerolidol, eucalyptol, dl-limonene, or terpinolene) assessed as enhancer. Attenuated Total Reflectance Infrared (ATR-FTIR) spectroscopy analysis performed to evaluate the effect of the transdermal films on skin barrier confirmed enhancer induced lipid bilayer disruption in stratum corneum, indicating its permeation enhancement effect. Full article
(This article belongs to the Special Issue Natural Polymers 2014)
Open AccessArticle Effect of Shear Resistance on Flexural Debonding Load-Carrying Capacity of RC Beams Strengthened with Externally Bonded FRP Composites
Polymers 2014, 6(5), 1366-1380; doi:10.3390/polym6051366
Received: 8 February 2014 / Revised: 29 April 2014 / Accepted: 4 May 2014 / Published: 13 May 2014
PDF Full-text (1890 KB) | HTML Full-text | XML Full-text
Abstract
Debonding failure is the main failure mode in flexurally strengthened reinforced concrete beams by externally bonded or near surface mounted fibre reinforced polymer (FRP) composites. It is believed that FRP debonding will be initiated if the shear stress on the concrete-FRP interface reaches
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Debonding failure is the main failure mode in flexurally strengthened reinforced concrete beams by externally bonded or near surface mounted fibre reinforced polymer (FRP) composites. It is believed that FRP debonding will be initiated if the shear stress on the concrete-FRP interface reaches the tensile strength of concrete. However, it was found through experimental and analytical studies that the debonding mechanism of FRP composites has the potential of shear failure in combination with debonding failure. Moreover, the shear failure probably influences the debonding failure. Presently, there are very little experimental and analytical studies to investigate the influence of shear resistance of reinforced concrete (RC) beam on FRP debonding failure. The current study investigates and analyzes the effect of shear resistance on FRP debonding failure based on test results. The analytical results show that the shear resistance of RC beam has a great effect on flexural debonding load-carrying capacity of FRP-strengthened RC beam. The influence of shear resistance on flexural debonding load-carrying capacity must be fully considered in flexural strengthening design of RC beams. Full article
(This article belongs to the Special Issue Fiber-Reinforced Polymer Composites in Structural Engineering)
Open AccessArticle Cost and Ductility Effectiveness of Concrete Columns Strengthened with CFRP and SFRP Sheets
Polymers 2014, 6(5), 1381-1402; doi:10.3390/polym6051381
Received: 26 December 2013 / Revised: 19 April 2014 / Accepted: 4 May 2014 / Published: 13 May 2014
Cited by 2 | PDF Full-text (445 KB) | HTML Full-text | XML Full-text
Abstract
Recently, steel fibre reinforced polymers (SFRP) sheets have been introduced for the repair and rehabilitation of concrete structures. Few researchers studied the behaviour of the concrete columns wrapped with SFRP sheets; however, several critical parameters such as the cost and ductility effectiveness of
[...] Read more.
Recently, steel fibre reinforced polymers (SFRP) sheets have been introduced for the repair and rehabilitation of concrete structures. Few researchers studied the behaviour of the concrete columns wrapped with SFRP sheets; however, several critical parameters such as the cost and ductility effectiveness of the SFRP wrapped concrete columns have been lightly addressed. Thus, the main objective of this paper is to study the cost and ductility effectiveness of SFRP wrapped concrete columns and compare the results with the conventionally used carbon FRP (CFRP) wrapped concrete columns. In addition, an analytical procedure to predict the cost effectiveness of SFRP wrapped concrete columns is also suggested, from which, a parametric study was conducted. The parametric study investigated the effect of the concrete strength, the number of SFRP layers, and the size and slenderness effects on the cost effectiveness of the concrete columns wrapped with SFRP sheets. The results from the cost and ductility effectiveness study indicated that the SFRP wrapped concrete columns showed enhanced performance over the CFRP wrapped concrete columns. The suggested analytical procedure proved to be a reliable and accurate method to predict the cost effectiveness parameter of SFRP wrapped concrete columns. The parametric study showed the significant impact of the investigated parameters on the cost effectiveness of concrete columns wrapped with SFRP sheets. Full article
(This article belongs to the Special Issue Selected Papers from "SMAR 2013")
Open AccessArticle Fabrication of CO2 Facilitated Transport Channels in Block Copolymer through Supramolecular Assembly
Polymers 2014, 6(5), 1403-1413; doi:10.3390/polym6051403
Received: 21 January 2014 / Revised: 13 April 2014 / Accepted: 6 May 2014 / Published: 14 May 2014
Cited by 8 | PDF Full-text (549 KB) | HTML Full-text | XML Full-text
Abstract
In this paper, the molecule 12-amidine dodecanoic acid (M) with ending groups of carboxyl and amidine groups respectively was designed and synthesized as CO2-responsive guest molecules. The block copolymer polystyrene-b-polyethylene oxide (PS-b-PEO) was chosen as the host
[...] Read more.
In this paper, the molecule 12-amidine dodecanoic acid (M) with ending groups of carboxyl and amidine groups respectively was designed and synthesized as CO2-responsive guest molecules. The block copolymer polystyrene-b-polyethylene oxide (PS-b-PEO) was chosen as the host polymer to fabricate a composite membrane through H-bonding assembly with guest molecule M. We attempted to tune the phase separation structure of the annealed film by varying the amount of M added, and investigated the nanostructures via transmission electron microscope (TEM), fourier transform infrared (FT-IR) etc. As a result, a reverse worm-like morphology in TEM image of bright PS phase in dark PEO/M matrix was observed for PS-b-PEO/M1 membrane in which the molar ratio of EO unit to M was 1:1. The following gas permeation measurement indicated that the gas flux of the annealed membranes dramatically increased due to the forming of ordered phase separation structure. As we expected, the obtained composite membrane PS-b-PEO/M1 with EO:M mole ratio of 1:1 presented an evident selectivity for moist CO2 permeance, which is identical with our initial proposal that the guest molecule M in the membranes will play the key role for CO2 facilitated transportation since the amidine groups of M could react reversibly with CO2 molecules in membranes. This work provides a supramolecular approach to fabricating CO2 facilitated transport membranes. Full article
(This article belongs to the Special Issue Non-Equilibrium Blockcopolymer Self-Assembly)
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Open AccessArticle 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 / Revised: 9 May 2014 / Accepted: 9 May 2014 / Published: 16 May 2014
Cited by 11 | PDF Full-text (3356 KB) | HTML Full-text | XML Full-text
Abstract
The classical Voorn-Overbeek thermodynamic theory of complexation and phase separation of oppositely charged polyelectrolytes is generalized to account for the charge accessibility and hydrophobicity of polyions, size of salt ions, and pH variations. Theoretical predictions of the effects of pH and salt concentration
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The classical Voorn-Overbeek thermodynamic theory of complexation and phase separation of oppositely charged polyelectrolytes is generalized to account for the charge accessibility and hydrophobicity of polyions, size of salt ions, and pH variations. Theoretical predictions of the effects of pH and salt concentration are compared with published experimental data and experiments we performed, on systems containing poly(acrylic acid) (PAA) as the polyacid and poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) or poly(diallyldimethyl ammonium chloride) (PDADMAC) as the polybase. In general, the critical salt concentration below which the mixture phase separates, increases with degree of ionization and with the hydrophobicity of polyelectrolytes. We find experimentally that as the pH is decreased below 7, and PAA monomers are neutralized, the critical salt concentration increases, while the reverse occurs when pH is raised above 7. We predict this asymmetry theoretically by introducing a large positive Flory parameter (= 0.75) for the interaction of neutral PAA monomers with water. This large positive Flory parameter is supported by molecular dynamics simulations, which show much weaker hydrogen bonding between neutral PAA and water than between charged PAA and water, while neutral and charged PDMAEMA show similar numbers of hydrogen bonds. This increased hydrophobicity of neutral PAA at reduced pH increases the tendency towards phase separation despite the reduction in charge interactions between the polyelectrolytes. Water content and volume of coacervate are found to be a strong function of the pH and salt concentration. Full article
(This article belongs to the Special Issue Polyelectrolytes 2014)
Open AccessArticle Modeling the Kinetics of Enhanced Photo-Polymerization under a Collimated and a Reflecting Focused UV Laser
Polymers 2014, 6(5), 1489-1501; doi:10.3390/polym6051489
Received: 27 March 2014 / Revised: 1 May 2014 / Accepted: 12 May 2014 / Published: 20 May 2014
Cited by 1 | PDF Full-text (310 KB) | HTML Full-text | XML Full-text
Abstract
This study explored the kinetics of ultraviolet (UV) laser photoinitiated polymerization in thick polymer systems to achieve improved polymerization efficiency and uniformity. The modeling system comprised an incident UV laser and its reflecting beam, which was focused by a concave mirror to compensate
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This study explored the kinetics of ultraviolet (UV) laser photoinitiated polymerization in thick polymer systems to achieve improved polymerization efficiency and uniformity. The modeling system comprised an incident UV laser and its reflecting beam, which was focused by a concave mirror to compensate for the exponential decay in the absorbing medium. The polymerization kinetic equation was numerically solved for the initiator concentration. The crossover time was calculated and compared among single beam, two collimated beam and collimated plus reflecting focused-beam systems. For the single beam case, analytic formulas for the time dependent incident beam is derived and demonstrated by measured data. A theoretical crossover time is defined to analyze the measured data based on the dynamic moduli. Lastly, the polymerization boundary dynamics are illustrated, showing the advantage of the combined two beam system. The numerical results provide useful guidance and a novel means for accelerated uniform photo-polymerization, which cannot be achieved by other means. Full article
Open AccessArticle Melt Free-Radical Grafting of Maleic Anhydride onto Biodegradable Poly(lactic acid) by Using Styrene as A Comonomer
Polymers 2014, 6(5), 1528-1543; doi:10.3390/polym6051528
Received: 15 April 2014 / Revised: 6 May 2014 / Accepted: 6 May 2014 / Published: 21 May 2014
Cited by 9 | PDF Full-text (389 KB) | HTML Full-text | XML Full-text
Abstract
Maleic anhydride (MA) was grafted onto poly(lactic acid) (PLA) in the presence of styrene (St) by using a free-radical grafting methodology. The grafting degree (Dg) of MA was increased from 0.65 wt % to 1.1 wt % with the St/MA
[...] Read more.
Maleic anhydride (MA) was grafted onto poly(lactic acid) (PLA) in the presence of styrene (St) by using a free-radical grafting methodology. The grafting degree (Dg) of MA was increased from 0.65 wt % to 1.1 wt % with the St/MA ratio up to 2/1, where the grafting efficiency (Eg) of MA was 27%. However, both Dg and Eg were decreased with further increasing of the St/MA ratio to 4/1. The Dg of MA increased with MA concentration and showed a maximum at 180 °C in the temperature range of 165 °C–190 °C. The grafting mechanisms of MA in the presence of St are analyzed based on titration, thermogravimetric analysis and infrared results, i.e., MA is grafted onto PLA chains via single monomers and a charge-transfer-complex (CTC) at St/MA ratios of ≤ 1/1, while dominantly via St-co-MA oligomers at St/MA ratios of around 2/1. Copolymerization rather than grafting of St and MA occurs at St/MA ratios of around 4/1. The thermal stability of PLA was compromised to a certain extent by the grafting of MA, resulting in reductions in the decomposition temperature (Td-5%) and molecular weight of the PLA. In addition, the crystallization and melting temperatures of the PLA were slightly reduced after the grafting. Full article
Open AccessArticle Structure of Microgels with Debye–Hückel Interactions
Polymers 2014, 6(5), 1602-1617; doi:10.3390/polym6051602
Received: 31 March 2014 / Revised: 13 May 2014 / Accepted: 19 May 2014 / Published: 23 May 2014
Cited by 13 | PDF Full-text (1089 KB) | HTML Full-text | XML Full-text
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 cross-links and with dangling ends at its surface. The self-avoiding polymers are
[...] Read more.
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 cross-links 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 rod-like behavior. Thereby, the average polymer radius of gyration follows a scaling curve in terms of polymer length and persistence length, with an asymptotic rod-like behavior for swollen microgels and self-avoiding walk behavior for weakly swollen gel particles. Full article
(This article belongs to the Special Issue Polyelectrolytes 2014)
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Open AccessArticle Azetidinium Functionalized Polytetrahydrofurans: Antimicrobial Properties in Solution and Application to Prepare Non Leaching Antimicrobial Surfaces
Polymers 2014, 6(5), 1618-1630; doi:10.3390/polym6051618
Received: 17 February 2014 / Revised: 24 April 2014 / Accepted: 12 May 2014 / Published: 23 May 2014
Cited by 3 | PDF Full-text (339 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
In this work, we report the antimicrobial efficacy of azetidinium functionalized polytetrahydrofurans in solution and their application in the preparation of non leaching, antimicrobial surfaces. The excellent antimicrobial efficacy of these water soluble polymers both in solution and on surfaces (>99.99%–100% bacterial growth
[...] Read more.
In this work, we report the antimicrobial efficacy of azetidinium functionalized polytetrahydrofurans in solution and their application in the preparation of non leaching, antimicrobial surfaces. The excellent antimicrobial efficacy of these water soluble polymers both in solution and on surfaces (>99.99%–100% bacterial growth inhibition) makes them excellent candidates for solving the hygiene related problems in the medical and hospital environment. Full article
(This article belongs to the Special Issue Biomimetic Polymers)
Open AccessArticle 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 / Revised: 4 May 2014 / Accepted: 8 May 2014 / Published: 23 May 2014
Cited by 6 | PDF Full-text (2854 KB) | HTML Full-text | XML Full-text | Supplementary Files
Abstract
Aptamers are short, single-stranded nucleic acids that fold into well-defined three dimensional (3D) structures that allow for binding 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
[...] Read more.
Aptamers are short, single-stranded nucleic acids that fold into well-defined three dimensional (3D) structures that allow for binding 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 Ultraviolet-visible (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-hyaluronan 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. Full article
(This article belongs to the Special Issue Polyelectrolytes 2014)
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Review

Jump to: Research

Open AccessReview Historical Perspective of Advances in the Science and Technology of Polymer Blends
Polymers 2014, 6(5), 1251-1265; doi:10.3390/polym6051251
Received: 21 March 2014 / Revised: 14 April 2014 / Accepted: 25 April 2014 / Published: 30 April 2014
Cited by 7 | PDF Full-text (229 KB) | HTML Full-text | XML Full-text
Abstract
This paper will review the important developments in the field of polymer blends. The subject of polymer blends has been one of the most prolific areas in polymer science and technology in the past five decades judging from publications and patents on the
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This paper will review the important developments in the field of polymer blends. The subject of polymer blends has been one of the most prolific areas in polymer science and technology in the past five decades judging from publications and patents on the subject. Although a continuing important subject, the peak intensity occurred in the 1970s and 1980s. The author has been active in this area for five decades and this paper is a recollection of some of the important milestones/breakthroughs in the field. The discussion will cover the development of the theory relevant to polymer blends, experimental methods, approaches to achieve compatibility in immiscible/incompatible blends, the nature of phase separation and commercial activity. Full article
(This article belongs to the Special Issue Polymer Blends)
Open AccessReview Polymeric Slippery Coatings: Nature and Applications
Polymers 2014, 6(5), 1266-1311; doi:10.3390/polym6051266
Received: 18 February 2014 / Revised: 16 April 2014 / Accepted: 23 April 2014 / Published: 30 April 2014
Cited by 7 | PDF Full-text (52769 KB) | HTML Full-text | XML Full-text
Abstract
We review recent developments in nature-inspired superhydrophobic and omniphobic surfaces. Water droplets beading on a surface at significantly high static contact angles and low contact-angle hystereses characterize superhydrophobicity. Microscopically, rough hydrophobic surfaces could entrap air in their pores resulting in a portion of
[...] Read more.
We review recent developments in nature-inspired superhydrophobic and omniphobic surfaces. Water droplets beading on a surface at significantly high static contact angles and low contact-angle hystereses characterize superhydrophobicity. Microscopically, rough hydrophobic surfaces could entrap air in their pores resulting in a portion of a submerged surface with air–water interface, which is responsible for the slip effect. Suberhydrophobicity enhances the mobility of droplets on lotus leaves for self-cleaning purposes, so-called lotus effect. Amongst other applications, superhydrophobicity could be used to design slippery surfaces with minimal skin-friction drag for energy conservation. Another kind of slippery coatings is the recently invented slippery liquid-infused porous surfaces (SLIPS), which are one type of omniphobic surfaces. Certain plants such as the carnivorous Nepenthes pitcher inspired SLIPS. Their interior surfaces have microstructural roughness, which can lock in place an infused lubricating liquid. The lubricant is then utilized as a repellent surface for other liquids such as water, blood, crude oil, and alcohol. In this review, we discuss the concepts of both lotus effect and Nepenthes slippery mechanism. We then present a review of recent advances in manufacturing polymeric and non-polymeric slippery surfaces with ordered and disordered micro/nanostructures. Furthermore, we discuss the performance and longevity of such surfaces. Techniques used to characterize the surfaces are also detailed. We conclude the article with an overview of the latest advances in characterizing and using slippery surfaces for different applications. Full article
(This article belongs to the Special Issue Biomimetic Polymers)
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Open AccessReview Naturapolyceutics: The Science of Utilizing Natural Polymers for Drug Delivery
Polymers 2014, 6(5), 1312-1332; doi:10.3390/polym6051312
Received: 31 January 2014 / Revised: 13 March 2014 / Accepted: 8 April 2014 / Published: 5 May 2014
Cited by 3 | PDF Full-text (1028 KB) | HTML Full-text | XML Full-text
Abstract
Naturapolyceutics defines the emerging science and technology platform that blends natural polymers and pharmaceutics for the design and development of drug delivery systems. Natural polymers due to their biological properties, sustainability, chemical flexibility, human and eco-friendliness are promising in this field. As drug
[...] Read more.
Naturapolyceutics defines the emerging science and technology platform that blends natural polymers and pharmaceutics for the design and development of drug delivery systems. Natural polymers due to their biological properties, sustainability, chemical flexibility, human and eco-friendliness are promising in this field. As drug delivery advances, there will be need for more polymers. Given that polymers utilized in pharmaceuticals require regulatory approval, robust processes are undertaken to facilitate the production of pharmaceutical grade natural polymers. This review provides insight into the processes—extraction, purification, modifications and characterizations—involved in the eventual utilization of natural polymers for drug delivery. The versatility of natural polymers and particularly modified natural polymers in targeted drug delivery, micro-/nano-drug delivery, theranostics, BioMEMs and generally in research and development of highly efficient, safe and quality products is demonstrated. Natural polymers are polymers of today and tomorrow. Therefore, the shift to undertake training, extensive research and subsequent commercialization of more natural polymers—novel and underutilized—for drug delivery is now! Full article
(This article belongs to the Special Issue Natural Polymers 2014)
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Open AccessReview RAFT Polymerization of Vinyl Esters: Synthesis and Applications
Polymers 2014, 6(5), 1437-1488; doi:10.3390/polym6051437
Received: 4 April 2014 / Revised: 6 May 2014 / Accepted: 9 May 2014 / Published: 20 May 2014
Cited by 29 | PDF Full-text (4650 KB) | HTML Full-text | XML Full-text
Abstract
This article is the first comprehensive review on the study and use of vinyl ester monomers in reversible addition fragmentation chain transfer (RAFT) polymerization. It covers all the synthetic aspects associated with the definition of precision polymers comprising poly(vinyl ester) building blocks, such
[...] Read more.
This article is the first comprehensive review on the study and use of vinyl ester monomers in reversible addition fragmentation chain transfer (RAFT) polymerization. It covers all the synthetic aspects associated with the definition of precision polymers comprising poly(vinyl ester) building blocks, such as the choice of RAFT agent and reaction conditions in order to progress from simple to complex macromolecular architectures. Although vinyl acetate was by far the most studied monomer of the range, many vinyl esters have been considered in order to tune various polymer properties, in particular, solubility in supercritical carbon dioxide (scCO2). A special emphasis is given to novel poly(vinyl alkylate)s with enhanced solubilities in scCO2, with applications as reactive stabilizers for dispersion polymerization and macromolecular surfactants for CO2 media. Other miscellaneous uses of poly(vinyl ester)s synthesized by RAFT, for instance as a means to produce poly(vinyl alcohol) with controlled characteristics for use in the biomedical area, are also covered. Full article
(This article belongs to the Special Issue Controlled/Living Radical Polymerization)
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Open AccessReview Polyelectrolyte Multilayers: Towards Single Cell Studies
Polymers 2014, 6(5), 1502-1527; doi:10.3390/polym6051502
Received: 3 March 2014 / Revised: 30 April 2014 / Accepted: 3 May 2014 / Published: 20 May 2014
Cited by 14 | PDF Full-text (2091 KB) | HTML Full-text | XML Full-text
Abstract
Single cell analysis (SCA) is nowadays recognized as one of the key tools for diagnostics and fundamental cell biology studies. The Layer-by-layer (LbL) polyelectrolyte assembly is a rather new but powerful technique to produce multilayers. It allows to model the extracellular matrix in
[...] Read more.
Single cell analysis (SCA) is nowadays recognized as one of the key tools for diagnostics and fundamental cell biology studies. The Layer-by-layer (LbL) polyelectrolyte assembly is a rather new but powerful technique to produce multilayers. It allows to model the extracellular matrix in terms of its chemical and physical properties. Utilization of the multilayers for SCA may open new avenues in SCA because of the triple role of the multilayer film: (i) high capacity for various biomolecules; (ii) natural mimics of signal molecule diffusion to a cell and (iii) cell patterning opportunities. Besides, light-triggered release from multilayer films offers a way to deliver biomolecules with high spatio-temporal resolution. Here we review recent works showing strong potential to use multilayers for SCA and address accordingly the following issues: biomolecule loading, cell patterning, and light-triggered release. Full article
(This article belongs to the Special Issue Biomimetic Polymers)
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Open AccessReview Structures and Synthesis of Zwitterionic Polymers
Polymers 2014, 6(5), 1544-1601; doi:10.3390/polym6051544
Received: 16 April 2014 / Revised: 3 May 2014 / Accepted: 8 May 2014 / Published: 23 May 2014
Cited by 44 | PDF Full-text (463 KB) | HTML Full-text | XML Full-text
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
[...] Read more.
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. Full article
(This article belongs to the Special Issue Polyelectrolytes 2014)
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