Polymer Chemistry Blog

Author of the Month: Prof. Makoto Obata

18 May 2015

Professor Makoto Obata received his Ph.D. degree in polymer chemistry from Hokkaido University, Japan in 1999. In 2000, he joined Professor Percec’s group at the University of Pennsylvania as a postdoctoral fellow. After one and a half years, he joined the faculty of Nara Women’s University from 2001 to 2009. In 2009, he moved to the University of Yamanashi, where he is now an Associate Professor of Applied Chemistry. His research area is the synthetic chemistry of functional polymers containing carbohydrates and dyes.

Take a look at Professor Makoto Obata research group’s website (please select translate for English).

What was your inspiration in becoming a chemist?

The training of my scientific expertise started at Asahikawa National College of Technology, Hokkaido, Japan, when I was 15 years old. I had an impressive supervisor at the college, and I was enthusiastic about studying my first research project on the synthesis of polymers bearing crown-ether for lithium ion capturing. After this experience, I was enchanted with the design and synthesis of new materials, especially organic materials.

What was the motivation to write your Polymer Chemistry article?

I started my career in Professor Yano’s laboratory at Nara Women’s University, Japan. His research area is the coordination chemistry of carbohydrate and its medicinal applications, such as anti-cancer drugs. When I worked with him, I recognised the potential of carbohydrates in medical applications. Currently, polyethylene glycol (PEG) is the first choice for water-soluble and biologically compatible polymers for drug delivery applications. In the future, I would like to make glycopolymer a functional alternative to PEG following a recently developed, controlled polymerisation technique.

Why did you choose Polymer Chemistry to publish your work?

My colleagues and I recognise that Polymer Chemistry is a high quality journal in this area.

In which upcoming conferences may our readers meet you?

I hope to attend the 2015 International Chemical Congress of Pacific Basin Societies (PACIFICHEM 2015).

How do you spend your spare time?

My wife and I love arts, especially 17th century Dutch painting, and animals (we love cats and dogs, and she deeply loves penguins!). However, it is not easy to see such masterpieces in Japan…

Which profession would you choose if you were not a scientist?

Even if I had not become a chemist, I would maybe have worked as a scientific engineer. I have never imagined joining any other kind of profession.

Aqueous RAFT synthesis of block and statistical copolymers of 2-(α-D-mannopyranosyloxy)ethyl methacrylate with 2-(N,N-dimethylamino)ethyl methacrylate and their application for nonviral gene delivery
Makoto Obata, Tomoya Kobori, Shiho Hirohara and Masao Tanihara
Polym. Chem., 2015,6, 1793-1804
DOI: 10.1039/C4PY01652A

Block copolymers composed of 2-(α-D-mannopyranosyloxy)ethyl methacrylate (ManEMA) and 2-(N,N-dimethylamino)ethyl methacrylate (DMAEMA) were synthesized by aqueous RAFT polymerization. The number-average degree of polymerization (DP_n) of ManEMA segments was constant at 33, and the DP_n of DMAEMA segments varied from 98 to 241. Statistical copolymers with a similar composition were also prepared via aqueous RAFT polymerization. The mannose-presenting nature was evaluated by a turbidimetric assay using Concanavalin A. The clustering rate of statistical copolymers was faster than those of the corresponding block copolymers. By contrast, no significant differences between block and statistical copolymers were found in their DNA-condensing ability as evaluated using gel shift assays and in their cytotoxicity in the transfection of plasmid DNA (pEGFP-N1) to HeLa cells. However, the overall transfection efficiency significantly depended on the monomer distribution. Statistical copolymers showed an overall transfection efficiency comparable to those of poly(DMAEMA·HCl)s, but block copolymers showed no detectable transfection under the same conditions.

Cyrille Boyer is a guest web-writer for Polymer Chemistry. He is currently an Associate Professor and an ARC-Future Fellow in the School of Chemical Engineering, University of New South Wales (Australia).

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Polymers curl up and take control

08 May 2015

By Kate Bandoo, Publishing Assistant.

Article written by Michaela Muehlberg

Scientists in Germany have successfully collapsed single polymer chains into dense nanoparticles, to make single-chain nanoparticles, by adding palladium.¹ The nanoparticles mimic enzymatic pockets with defined environments around their metal centres and can catalyse a carbon coupling reaction.

The intramolecular crosslinking process creates single-chain nanoparticles that catalyse a Sonogashira coupling reaction

Enzymes use their carefully shaped reaction cavities to selectively catalyse organic reactions. Industrial processes crave selectivity, but also demand straightforward procedures. Synthesising and separating enzymes in practical quantities is, however, tricky, so they aren’t always suitable for industry. One solution to this might be single-chain nanoparticles, which have recently become a hot topic in the field of polymer chemistry.² Their applications range from sensing to recognition, and medicine to catalysis, but only a few groups have studied their synthesis and even fewer have looked at the introduction of metals.

To read the full article visit Chemistry World.

Pd-complex driven formation of single-chain nanoparticles
Johannes Willenbacher, Ozcan Altintas, Vanessa Trouillet, Nicolai Knöfel, Michael J. Monteiro, Peter W. Roesky and Christopher Barner-Kowollik
Polym. Chem., 2015, Advance Article
DOI: 10.1039/C5PY00389J, Paper

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2015 Polymer Chemistry Lectureship awarded to Richard Hoogenboom

06 May 2015

By Katie Nicholson, Development Editor.

It is with great pleasure that we announce Professor Richard Hoogenboom (Ghent University) as the recipient of the inaugural 2015 Polymer Chemistry Lectureship award.

This award, which will be an annual event for the journal, honours an early-stage career researcher who has made significant contribution to the polymer chemistry field. The recipient is selected by the Polymer Chemistry Editorial Board from a list of candidates nominated by the community.

Read on to find out more about Richard…

Professor Richard Hoogenboom was born in 1978 in Rotterdam (the Netherlands) and studied chemical engineering at the Eindhoven University of Technology (the Netherlands). In 2005, he obtained his Ph.D. under the supervision of Professor Ulrich S. Schubert and continued working as a project leader for the Dutch Polymer Institute, partially combined with a position as senior product developer at Dolphys Medical BV. After postdoctoral training at the RWTH Aachen with Professor Martin Moeller and at the Radboud University Nijmegen with Professor Roeland Nolte, he was appointed as associate professor at Ghent University in 2010 and in October 2014 he was promoted to full professor. His research focuses on adaptive and responsive materials based on stimuli-responsive polymers, supramolecular polymers, and poly(2-oxazoline)s. Professor Hoogenboom has published more than 260 refereed scientific articles (h-index 47) and is currently Associate Editor for European Polymer Journal and Australian Journal of Chemistry.

To learn more about Richard’s research why not read his recent articles:

Dye immobilization in halochromic nanofibers through blend electrospinning of a dye-containing copolymer and polyamide-6
Iline Steyaert, Gertjan Vancoillie, Richard Hoogenboom and Karen De Clerck
Polym. Chem., 2015, 6, 2685-2694

Thermoresponsive polymeric temperature sensors with broad sensing regimes
Qilu Zhang, Gertjan Vancoillie, Maarten A. Mees and Richard Hoogenboom
Polym. Chem., 2015, 6, 2396-2400

Accelerated living cationic ring-opening polymerization of a methyl ester functionalized 2-oxazoline monomer
Petra J. M. Bouten, Dietmar Hertsen, Maarten Vergaelen, Bryn D. Monnery, Marcel A. Boerman, Hannelore Goossens, Saron Catak, Jan C. M. van Hest, Veronique Van Speybroeck and Richard Hoogenboom
Polym. Chem., 2015, 6, 514-518

We would like to thank everybody who nominated a candidate for the Lectureship; we received many excellent nominations, and the Editorial Board had a difficult task in choosing between some outstanding candidates.

Please join us in congratulating Richard by adding your comments below.

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Paper of the week: Patterning of individual Staphylococcus aureus bacteria onto photogenerated polymeric surface structures

24 Apr 2015

By Remzi Becer, web writer.

Palacios-Cuesta et al. describe the patterning of individual Staphylococcus aureus bacteria onto photogenerated polymeric surface structures.

Microorganisms have a remarkable ability to adhere to virtually any type of abiotic surface, proliferate and subsequently form biofilms. Since materials may need to interact differently with microorganisms, the adherent or repellent properties of materials towards bacteria are an extremely important consideration in their design. For example, materials used as implants need to remain free from contamination, in order to reduce device-associated infections, and hence, antifouling surfaces are prepared using water repellent polymers or by anchoring antimicrobial compounds. Conversely, surfaces capable of controlled immobilization and removal of microorganisms have been equally explored for a rather broad range of applications, including sophisticated systems such as biosensors or biomolecular motors. Thus far, precise immobilisation of microorganisms, and in particular bacteria, onto surfaces has been achieved by using a range of different fabrication approaches. However, there are relatively few examples of controlled immobilisation of single bacteria that don’t involve expensive approaches or time-consuming multistep procedures.

In this paper, Palacios-Cuesta and colleagues describe the development of different surface patterns using a photolithographic-based technique that does not require the use of high resolution masks or clean rooms and produces surface patterns with micrometer and submicrometer resolution. The procedure is based on the cross-linking and degradation processes occurring in polystyrene upon exposure to UV light. Together, these processes produce different patterns depending, not only on the mask, but also on the experimental conditions employed. With this approach it is possible to produce patterns with nanoscale resolution without expensive fine focalisation settings. Of particular interest, the authors demonstrate the feasibility of this strategy to incorporate functional groups to modulate the affinity between the bacteria and the surface. In particular, hydrophilic segments, i.e. poly(acrylic acid) that favour bacterial immobilisation are introduced. The strategy employed allows not only the incorporation of functional groups, but also enables the fine tuning of the amount of hydrophilic functional groups. This unique feature is used by the authors to determine the role of surface hydrophilicity on the adhesion of Staphylococcus aureus onto the different surface patterns. Finally, those surfaces on which both photodegradation and photo-cross-linking occur produce thin patterns largely below the micrometer that are then used to prepare arrays of isolated S. aureus bacteria. The formation of bacterial arrays of S. aureus on the single-cell level has been a challenge since they exhibit a large tendency to grow in clusters. This technology is exciting given its potential for enabling the isolation of single bacteria for diagnosis, and the study of bacterial populations at the single cell level.

Patterning of individual Staphylococcus aureus bacteria onto photogenerated polymeric surface structures by Marta Palacios-Cuesta, Aitziber L. Cortajarena, Olga García and Juan Rodríguez-Hernández, Polym. Chem., 2015, 6, 2677-2684.

Remzi Becer is a web-writer and Advisory Board member for Polymer Chemistry. He is currently a Senior Lecturer in Materials Science and the director of the Polymer Science and Nanotechnology masters programme at Queen Mary, University of London. Visit www.becergroup.com for more information.

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2015 International Polymer Colloids Group Conference

07 Apr 2015

By Pete Livermore, Deputy Editor.

We are pleased to announce the 2015 International Polymer Colloids Group Conference to be held on June 28 – July 3, 2015 at The University of New Hampshire, Durham, USA.

The 2015 program will bring together world leading scientists to discuss the latest developments in the area of colloidal polymer science. The talks of the invited speakers will feature a balance of traditional and emerging applications for polymer colloids, following the themes of colloids for life, engineering colloids, and colloidal machines. You can see a list of confirmed speakers here.

You can register for the 2015 IPCG Conference here.

SCIENTIFIC COMMITTEE

Prof. Stefan Bon, Conference Chair, Warwick University, UK
Prof. Jose R. Leiza, University of the Basque Country, Spain
Dr. Willie Lau, Oriental Yuhong, CN

ORGANIZING COMMITTEE

Prof. John Tsavalas, University of New Hampshire, USA

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Paper of the week: Nucleobase-functionalized acrylic ABA triblock copolymers and supramolecular blends

07 Apr 2015

By Remzi Becer, web writer.

Long et al describe the synthesis of nucleobase-functionalized acrylic triblock copolymers.

Reversible addition-fragmentation chain transfer (RAFT) polymerization afforded the unprecedented synthesis of well-defined acrylic ABA triblock copolymers with nucleobase-functionalized external blocks and a central poly(n-butyl acrylate) (PnBA) block. Size exclusion chromatography (SEC) confirmed the molecular weight and molecular weight distribution of the central block. ¹H NMR spectroscopy revealed the successful chain extension of the PnBA macro-chain transfer agent (CTA) using adenine or thymine-functionalized acrylic monomers. The acrylic monomer with a flexible spacer to the pendant nucleobases promoted intermolecular recognition of nucleobases and long range segmental motion of polymer main chains. The external block glass transition temperatures (T_g‘s) of thymine (T) and adenine (A) functionalized blocks were 52 °C and 76 °C, respectively. Thermomechanical and morphological analysis revealed the effect of processing conditions on self-assembly and microphase-separated morphology of nucleobase-functionalized ABA copolymers. Thymine and adenine-functionalized ABA triblocks formed a thermodynamically stable, hydrogen-bonded complex upon blending. The supramolecular blend exhibited a cylindrical microphase-separated morphology with an extended plateau window compared to the individual block copolymers. The complementary hydrogen bonding between adenine and thymine formed a thermally labile, physically crosslinked, network that exhibited enhanced mechanical performance with melt processability. Thus, these ABA nucleobase-functionalized block copolymers demonstrate potential as thermoplastic elastomers for hot melt adhesives and coatings.

Nucleobase-functionalized acrylic ABA triblock copolymers and supramolecular blends by Keren Zhang, Motohiro Aiba, Gregory B. Fahs, Amanda G. Hudson, William D. Chiang, Robert B. Moore, Mitsuru Ueda and Timothy E. Long Polym. Chem., 2015,6, 2434-2444

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Author of the Month: Prof. Philipp Vana

30 Mar 2015

By Cyrille Boyer.

Philipp Vana studied Chemistry at the University of Vienna, Austria, were he obtained a Master of Natural Sciences in 1996 and a Doctor of Natural Sciences in 1999 after investigating chain-length dependent termination kinetics in radical polymerisation in Professor Oskar-Friedrich Olaj’s group. Parallel to his PhD, he studied economics and law and obtained a diploma from the Technical University Vienna and a Master of Business Administration from the Danube-University Krems, Austria. Between 2001 and 2003 he was a Schrödinger-Fellow of the Austrian Science Fund at the Centre for Advanced Macromolecular Design (CAMD) at the University of New South Wales, Australia, were he work in the group of Professor Tom Davis in the field of RAFT polymerisation kinetics. In 2003, he established an independent research group at the University of Göttingen, Germany, specifically focusing on macromolecular design and functional polymer materials. In 2005 he became a Fellow of the Japan Society for the Promotion of Science at Kyoto University in Professor Takeshi Fukuda’s group, were he moved into the field of polymer brushes and surface modifications. In 2008 he was granted the prestigious Heisenberg-Professorship of the German Research Foundation (DFG) at the University of Göttingen, where he finally became a Full Professor for Macromolecular Chemistry in 2010 after declining offers from Leipzig University and Duisburg-Essen University. Since 2013 he has been the director of the Institute of Physical Chemistry in Göttingen. Philipp has published more than 100 original research papers in addition to several book chapters, reviews and patents.

His scientific interests are macromolecular chemistry with a focus on tailored polymer microstructures and topologies as well as kinetic and mechanistic studies of polymerisation processes. He works on biomimetic high-performance polymers, polymer brushes and films on solid surfaces, functionalised polymers, printing inks, tire materials, liquid crystal displays and UV-switchable block copolymers. He also works on kinetics and mechanisms of radical polymerisations, which are studied via pulsed laser methods coupled with highly time-resolved EPR spectroscopy as well as via computer simulations. A special focus in polymer analytics is on soft ionisation mass spectrometry, AFM, mechanical testing of polymers, ellipsometry, and IR-spectroscopy.

Find out more about Philip Vana’s research by visiting his group Web-site.

What was your inspiration in becoming a chemist?

I am from a family of natural scientists – my father was a physicist, my mother a chemist and so I got in touch with all the interesting aspects of natural science very early on. However, I noticed during my childhood that my interests lay more in the field of biology and living matter and so I decided to study biochemistry; I was worried about the career perspectives of a pure biologist. During my studies I got in touch with chemistry and quickly noticed that it was extremely exciting and interesting, this changed my original plan and I switched to chemistry. I haven’t regretted the decision ever since and I am very happy to be a synthetic chemist. I then chose the field of polymer chemistry, I think it is the most exciting area of chemistry due to its large diversity. In the end, I came back to my original interests in biology by working on bio-inspired materials.

What was the motivation to write your Polymer Chemistry article?

I was always intrigued by the complexity and beauty of natural systems. I find it exciting to learn from nature by copying important aspects of natural materials and transpose them to purely synthetic fabrics. When I was writing a grant application several years ago, I accidently saw a picture of titin on the transparency of a conference talk. For me, as a polymer chemist, the structure looked like a very regular polymer made of individual ring-like monomers. At the time I was a PI in a graduate school in which hydrogen bonds were investigated in great detail. I started to interconnect all these aspects and came up with a project plan that aimed to fabricate a synthetic titin. To our delight, the project was granted but it then took some time to arrive at the final material because we first had to explore and optimise all the individual components of the system, including ring polymers. However, we are very happy that we could indeed mimic the structure of titin.

Why did you choose Polymer Chemistry to publish your work?

Honestly, this was the first time that I published in Polymer Chemistry. Many of our earlier work was very much related to physical chemistry, engineering, analytics and physics of polymers and I did not consider our work as being pure polymer chemistry. Nevertheless, I was very much impressed by the rise of this journal, in which many of my friends and colleagues are deeply involved. I also find the topics that are covered extremely interesting, especially the strong focus on controlled radical polymerisation, I am a loyal reader of this beautiful journal. Within this context, I find it amusing that my first paper in Polymer Chemistry is not related to controlled radical polymerisation at all, but we present a new way of forming modular polycyclic structures via step-growth, which we had never used before. In any case, I found this topic to be exactly in scope of Polymer Chemistry, which made it easy for me to chose it for this publication.

In which upcoming conferences may our readers meet you?

As I will shortly become dean of our faculty for the next two years, I cannot make exact plans for the near future but you can always meet my students and colleagues from my group at different conferences world-wide presenting our work. A group of my students, for instance will present our results in the field of nano-composite materials at the Fourth International Conference on Multifunctional, Hybrid and Nanomaterials in Sitges, Spain, 9 – 13 March 2015.

How do you spend your spare time?

I have a family with four small children and my wife and I are both work full days. This means that most of my time outside of the university is spent taking care of my children and organising daily life, which I very much enjoy. There is consequently not much time left for personal hobbies in the moment, but the time with my family gives me strength for my scientific endeavours as it clears my mind and wipes away old thoughts making room for new ideas.

Which profession would you choose if you were not a scientist?

Actually, I am very pleased with my job and enjoy most of my time being a Professor of Macromolecular Chemistry. The second best choice for me would have been an architect. I always loved making construction designs and graphics and I would love to design buildings from scratch. In a way, this would be similar to what I am doing now, but aiming at much larger structures. As an architect of molecules, however I am also very happy, although I haven’t found any inhabitants for our little macromolecular constructions yet!

Titin-mimicking polycyclic polymers with shape regeneration and healing properties

Jan-Hendrik Schuetz, Peng Wentao and Philipp Vana

Polycyclic polymers based on cyclic (ABC)_n-multiblock-copolymers are formed via stepwise polymerisation of three individual blocks and exploiting the ring merging reaction of these ring polymers. The so-obtained precursor ring-polymers were interconnected via click reaction. Small blocks within the rings with the ability to form self-complementary hydrogen bonds lead to intra- and intermolecular links between polycyclic polymers. The obtained materials, which mimic nature’s paragon Titin, have some extraordinary material properties concerning elasticity and energy dissipation.

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Paper of the week: Renewable, fluorescent, and thermoresponsive cellulose copolymers

30 Mar 2015

By Remzi Becer, web writer.

Hufendiek et al. report the preparation of renewable, fluorescent, and thermoresponsive cellulose copolymers via light-induced ligation in solution copolymers.

Hufendiek et al. introduce a mild photochemically driven strategy for the synthesis of fluorescent cellulose copolymers using filter paper as the starting material. Thermoresponsive behaviour in water is imparted to the brush-like structures by grafting of poly(N-isopropylacrylamide) side chains. All reactions take place in homogenous solutions, allowing the design of novel advanced materials from renewable resources.

Renewable, fluorescent, and thermoresponsive: cellulose copolymers via light-induced ligation in solution by Andrea Hufendiek, Christopher Barner-Kowollik and Michael A. R. Meier,Polym. Chem., 2015, 6, 2188-2191

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Paper of the week: Nanoscale detection of metal-labeled copolymers in patchy polymersomes

24 Mar 2015

By Remzi Becer, web writer.

Ruiz-Pérez et al. report the nanoscale detection of metal-labelled copolymers in patchy polymersomes.

The synthesis of polymersome-forming block copolymers using two different synthetic routes based on Atom Transfer Radical Polymerisation (ATRP) and Reversible Addition Fragmentation chain Transfer (RAFT) polymerisation is reported. Functionalisation with 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) allowed the block copolymer chains to be labelled with electron-dense metal ions (e.g. indium). The resulting metal-conjugated copolymers can be visualised by transmission electron microscopy with single chain resolution, hence enabling the study of polymer/polymer immiscibility and phase separation on the nano-scale.

Nanoscale detection of metal-labeled copolymers in patchy polymersomes by Lorena Ruiz-Pérez, Jeppe Madsen, Efrosyni Themistou, Jens Gaitzsch, Léa Messager, Steven P. Armes and Giuseppe Battaglia, Polym. Chem., 2015, 6, 2065-2068.

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Polymer Chemistry Blog

Author of the Month: Prof. Makoto Obata

Top 10 most-read Polymer Chemistry articles – Q1 2015

Polymers curl up and take control

2015 Polymer Chemistry Lectureship awarded to Richard Hoogenboom

Paper of the week: Patterning of individual Staphylococcus aureus bacteria onto photogenerated polymeric surface structures

2015 International Polymer Colloids Group Conference

Paper of the week: Nucleobase-functionalized acrylic ABA triblock copolymers and supramolecular blends

Author of the Month: Prof. Philipp Vana

Titin-mimicking polycyclic polymers with shape regeneration and healing properties

Paper of the week: Renewable, fluorescent, and thermoresponsive cellulose copolymers

Paper of the week: Nanoscale detection of metal-labeled copolymers in patchy polymersomes

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