Complex Macromolecular Architectures

A special issue of Polymers (ISSN 2073-4360).

Deadline for manuscript submissions: closed (30 September 2015) | Viewed by 57375

Special Issue Editor


E-Mail Website
Guest Editor
Makromolekulare Chemie, Institut für Physikalische Chemie, Georg-August-Universität Göttingen, Tammannstraße 6, D-37077 Göttingen, Germany
Interests: controlled radical RAFT polymerization; synthesis of complex macromolecular architectures and functional polymers; biomimetic polymer design; polymerizations from surfaces; organic–inorganic hybrid materials; kinetics and mechanism of radical polymerizations; mechanical properties of polymers; modeling and simulation of polymerization processes; electrospray ionization (ESI) mass spectrometry; ion-mobility mass spectrometry
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

The scope of this special issue is to collate reports about recent progress and future perspectives in the field of complex macromolecular architecture. It will focus on synthesis, characterization, and applications.

The tailoring of well-defined complex macromolecular architecture constitutes the molecular basis for advanced polymer materials. The recent advent of a multitude of controlled polymerization methods, which greatly outperform conventional polymerization processes with respect to topological control, has had a major impact on this field. Consequently, macromolecular architectures of stunning complexity are now available with relative ease, which were far beyond the wildest dreams of polymer chemists just short time ago. A variety of block copolymers, star polymers, ring polymers, graft and comb copolymers, gradient copolymers, and hyper-branched polymers has been developed and explored over the last few years. Their structures have been tailored to produce specific properties in the resulting material. Phase separation and self-ordering phenomena have been exploited to produce functional materials, including applications in energy conversion, e.g., solar cells; nanomedicine, e.g., drug delivery; and materials science, where they are used for the design of functional, responsive, or high mechanical performance materials.

The wide array of possible applications finds its origin in the tailored design of polymer topology on a molecular level, for which new approaches are constantly emerging. Despite the rapid progress polymer science has made in recent times with respect to topological control, many issues have yet to be addressed to exploit the full potentials of this fascinating class of materials. These open research topics, along with prospects for the future, will be the focus of this special issue.

Prof. Dr. Philipp Vana
Guest Editor

Manuscript Submission Information

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. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short 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 thoroughly refereed through a single-blind 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 semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • block copolymers
  • star polymers
  • comb polymers
  • gradient copolymers
  • hyperbranched polymers
  • functionalized polymers
  • topological control

Published Papers (7 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

2127 KiB  
Article
Tailoring Confinement: Nano-Carrier Synthesis via Z-RAFT Star Polymerization
by Nadja Förster, Sonja Schmidt and Philipp Vana
Polymers 2015, 7(4), 695-716; https://doi.org/10.3390/polym7040695 - 10 Apr 2015
Cited by 5 | Viewed by 7520
Abstract
A new pathway to nano-sized hollow-sphere particles from six-arm star polymers with an amphiphilic core-corona structure, synthesized in a four-step-procedure by means of reversible addition-fragmentation chain transfer (RAFT) polymerization is presented, in order to achieve more stable and versatile nano-container systems, which could [...] Read more.
A new pathway to nano-sized hollow-sphere particles from six-arm star polymers with an amphiphilic core-corona structure, synthesized in a four-step-procedure by means of reversible addition-fragmentation chain transfer (RAFT) polymerization is presented, in order to achieve more stable and versatile nano-container systems, which could be applied in the fields of drug delivery or catalyst storage. Star-shaped amphiphilic, diblock copolymers serve as globular platforms for synthesizing uniform hollow structures. By the introduction of monomer units carrying UV-cross-linkable dimethyl maleimido functionalities into the outer sphere of these star polymers, the carrier’s shell could be stabilized under UV-irradiation. After removal of the RAFT-core—constituting the central hub of the star polymer—by aminolysis, the carrier is ready for loading. Full article
(This article belongs to the Special Issue Complex Macromolecular Architectures)
Show Figures

Graphical abstract

3847 KiB  
Article
Phase Behavior of Copolymers Confined in Multi-Walled Nanotubes: Insights from Simulations
by Yuxin Zuo, Guoqiang Wang, Ying Yu, Chuncheng Zuo, Luyou Shi, Fulei Shi and Jie Wei
Polymers 2015, 7(1), 120-133; https://doi.org/10.3390/polym7010120 - 16 Jan 2015
Cited by 5 | Viewed by 5343
Abstract
In this paper, the self-assembly process of diblock copolymers confined in multi-walled cylindrical nanotubes is systematically investigated using a molecular dynamics (MD) method. The dependence of resultant morphologies on the degree of confinement and on the interaction strength between nanotubes and copolymers is [...] Read more.
In this paper, the self-assembly process of diblock copolymers confined in multi-walled cylindrical nanotubes is systematically investigated using a molecular dynamics (MD) method. The dependence of resultant morphologies on the degree of confinement and on the interaction strength between nanotubes and copolymers is studied comprehensively. When the wall surfaces are not preferential, results indicate that geometric confinement significantly influences copolymer conformations. In addition, the thickness of the helical lamellar structure increases with interaction strength and confinement size. In cases where the nanotubes are strongly attracted to one copolymer block, the confinement effect weakens as geometric space increases. Findings explain the dependence of chain conformation on the degree of confinement and the strength of surface preferences. Full article
(This article belongs to the Special Issue Complex Macromolecular Architectures)
Show Figures

Graphical abstract

1849 KiB  
Article
Tuning the Solubility of Copper Complex in Atom Transfer Radical Self-Condensing Vinyl Polymerizations to Control Polymer Topology via One-Pot to the Synthesis of Hyperbranched Core Star Polymers
by Zong-Cheng Chen, Chia-Ling Chiu and Chih-Feng Huang
Polymers 2014, 6(10), 2552-2572; https://doi.org/10.3390/polym6102552 - 30 Sep 2014
Cited by 20 | Viewed by 9760
Abstract
In this paper, we propose a simple one-pot methodology for proceeding from atom transfer reaction-induced conventional free radical polymerization (AT-FRP) to atom transfer self-condensing vinyl polymerization (AT-SCVP) through manipulation of the catalyst phase homogeneity (i.e., CuBr/2,2'-bipyridine (CuBr/Bpy)) in a mixture of [...] Read more.
In this paper, we propose a simple one-pot methodology for proceeding from atom transfer reaction-induced conventional free radical polymerization (AT-FRP) to atom transfer self-condensing vinyl polymerization (AT-SCVP) through manipulation of the catalyst phase homogeneity (i.e., CuBr/2,2'-bipyridine (CuBr/Bpy)) in a mixture of styrene (St), 4-vinyl benzyl chloride (VBC), and ethyl 2-bromoisobutyrate. Tests of the solubilities of CuBr/Bpy and CuBr2/Bpy under various conditions revealed that both temperature and solvent polarity were factors affecting the solubility of these copper complexes. Accordingly, we obtained different polymer topologies when performing AT-SCVP in different single solvents. We investigated two different strategies to control the polymer topology in one-pot: varying temperature and varying solvent polarity. In both cases, different fractions of branching revealed the efficacy of varying the polymer topology. To diversify the functionality of the peripheral space, we performed chain extensions of the resulting hyperbranched poly(St-co-VBC) macroinitiator (name as: hbPSt MI) with either St or tBA (tert-butyl acrylate). The resulting hyperbranched core star polymer had high molecular weights (hbPSt-g-PSt: Mn = 25,000, Đ = 1.77; hbPSt-g-PtBA: Mn = 27,000, Đ = 1.98); hydrolysis of the tert-butyl groups of the later provided a hyperbranched core star polymer featuring hydrophilic poly(acrylic acid) segments. Full article
(This article belongs to the Special Issue Complex Macromolecular Architectures)
Show Figures

Graphical abstract

1905 KiB  
Article
Polyplex Formation Influences Release Mechanism of Mono- and Di-Valent Ions from Phosphorylcholine Group Bearing Hydrogels
by A. Nolan Wilson, Mark Blenner and Anthony Guiseppi-Elie
Polymers 2014, 6(9), 2451-2472; https://doi.org/10.3390/polym6092451 - 25 Sep 2014
Cited by 13 | Viewed by 7618
Abstract
The release of monovalent potassium and divalent calcium ions from zwitterionic phosphorylcholine containing poly(2-hydroxyethyl methacrylate) (pHEMA)-based hydrogels was studied and the effects of polymer swelling, ion valence and temperature were investigated. For comparison, ions were loaded during hydrogel formulation or loaded by partitioning [...] Read more.
The release of monovalent potassium and divalent calcium ions from zwitterionic phosphorylcholine containing poly(2-hydroxyethyl methacrylate) (pHEMA)-based hydrogels was studied and the effects of polymer swelling, ion valence and temperature were investigated. For comparison, ions were loaded during hydrogel formulation or loaded by partitioning following construct synthesis. Using the Koshmeyer-Peppas release model, the apparent diffusion coefficient, Dapp, and diffusional exponents, n, were Dapp (pre-K+) = 2.03 × 105, n = 0.4 and Dapp (post-K+) = 1.86 × 105, n = 0.33 respectively, indicative of Fickian transport. The Dapp (pre-Ca2+) = 3.90 × 106, n = 0.60 and Dapp (post-Ca2+) = 2.85 × 106, n = 0.85, respectively, indicative of case II and anomalous transport. Results indicate that divalent cations form cation-polyelectrolyte anion polymer complexes while monovalent ions do not. Temperature dependence of potassium ion release was shown to follow an Arrhenius-type relation with negative apparent activation energy of −19 ± 15 while calcium ion release was temperature independent over the physiologically relevant range (25–45 °C) studied. The negative apparent activation energy may be due to temperature dependent polymer swelling. No effect of polymer swelling on the diffusional exponent or rate constant was found suggesting polymer relaxation occurs independent of polymer swelling. Full article
(This article belongs to the Special Issue Complex Macromolecular Architectures)
Show Figures

Graphical abstract

3815 KiB  
Article
Surface-Induced Ordering on Model Liquid Crystalline Dendrimers
by Zerihun G. Workineh and Alexandros G. Vanakaras
Polymers 2014, 6(8), 2082-2099; https://doi.org/10.3390/polym6082082 - 30 Jul 2014
Cited by 12 | Viewed by 5477
Abstract
The surface alignment of liquid crystalline dendrimers (LCDrs) is a key factor for many of their potential applications. Here, we present results from Monte Carlo simulations of LCDrs adsorbed on flat, impenetrable aligning substrates. A tractable coarse-grained force field for the inter-dendritic and [...] Read more.
The surface alignment of liquid crystalline dendrimers (LCDrs) is a key factor for many of their potential applications. Here, we present results from Monte Carlo simulations of LCDrs adsorbed on flat, impenetrable aligning substrates. A tractable coarse-grained force field for the inter-dendritic and the dendrimer-substrate interactions is introduced. We investigate the conformational and ordering properties of single, end-functionalized LCDrs under homeotropic, random (or degenerate) planar and unidirectional planar aligning substrates. Depending on the anchoring constrains to the mesogenic units of the LCDr and on temperature, a variety of stable ordered LCDr states, differing in their topology, are observed and analyzed. The influence of the dendritic generation and core functionality on the surface-induced ordering of the LCDrs are examined. Full article
(This article belongs to the Special Issue Complex Macromolecular Architectures)
Show Figures

Graphical abstract

1478 KiB  
Article
Macromolecular Architectures Designed by Living Radical Polymerization with Organic Catalysts
by Miho Tanishima, Atsushi Goto, Lin Lei, Akimichi Ohtsuki, Hironori Kaji, Akihiro Nomura, Yoshinobu Tsujii, Yu Yamaguchi, Hiroto Komatsu and Michihiko Miyamoto
Polymers 2014, 6(2), 311-326; https://doi.org/10.3390/polym6020311 - 27 Jan 2014
Cited by 28 | Viewed by 9227
Abstract
Well-defined diblock and triblock copolymers, star polymers, and concentrated polymer brushes on solid surfaces were prepared using living radical polymerization with organic catalysts. Polymerizations of methyl methacrylate, butyl acrylate, and selected functional methacrylates were performed with a monofunctional initiator, a difunctional initiator, a [...] Read more.
Well-defined diblock and triblock copolymers, star polymers, and concentrated polymer brushes on solid surfaces were prepared using living radical polymerization with organic catalysts. Polymerizations of methyl methacrylate, butyl acrylate, and selected functional methacrylates were performed with a monofunctional initiator, a difunctional initiator, a trifunctional initiator, and a surface-immobilized initiator. Full article
(This article belongs to the Special Issue Complex Macromolecular Architectures)
Show Figures

Graphical abstract

1106 KiB  
Article
Photocrosslinkable Star Polymers via RAFT-Copolymerizations with N-Ethylacrylate-3,4-dimethylmaleimide
by Nadja Förster, Ann-Christin Pöppler, Dietmar Stalke and Philipp Vana
Polymers 2013, 5(2), 706-729; https://doi.org/10.3390/polym5020706 - 10 Jun 2013
Cited by 12 | Viewed by 11651
Abstract
This paper describes the Z-RAFT-star copolymerization of n-butyl acrylate (BA) and N-isopropyl acrylamide (NIPAm), respectively, with N-ethylacrylate-3,4-dimethylmaleimide (1.1), a monomer carrying a UV-reactive unit that undergoes photocrosslinking. Addition of 1.1 slows down the polymerization rate both for BA [...] Read more.
This paper describes the Z-RAFT-star copolymerization of n-butyl acrylate (BA) and N-isopropyl acrylamide (NIPAm), respectively, with N-ethylacrylate-3,4-dimethylmaleimide (1.1), a monomer carrying a UV-reactive unit that undergoes photocrosslinking. Addition of 1.1 slows down the polymerization rate both for BA and for NIPAm polymerization. Double star formation due to radical attack to the 3,4-dimethylmaleimide moiety was found in the case of BA. Dead polymer formation, presumably due to aminolysis as side-reaction, was pronounced in the NIPAm system. These two effects broadened the molar mass distributions, but did not impede the formation of functional star polymers. The composition of the copolymers as well as the reactivity ratios for the applied comonomers were determined via NMR spectroscopy (BA-co-1.1 r1.1 = 2.24 rBA = 0.95; NIPAm-co-1.1 r1.1 = 0.96 rNIPAm = 0.05). In both cases, the comonomer is consumed preferably in the beginning of the polymerization, thus forming gradient copolymer stars with the UV-reactive units being located in the outer sphere. Full article
(This article belongs to the Special Issue Complex Macromolecular Architectures)
Show Figures

Figure 1

Back to TopTop