Archive for May, 2015

Recent Appointees in Materials Science 2015 Conference (RAMS2015)

Recent Appointees in Materials Science 2015 Conference RAMS

We are delighted to announce that the Recent Appointees in Materials Science 2015 Conference (RAMS2015) will be held at the University of Warwick on 16-17th September 2015.

Deadlines and dates

Registration will open shortly so be sure to sign up to this essential meeting before 1st September 2015! The cost of registration is £125 for accommodation and meals, including the conference banquet at Warwick Castle. A reduced rate of £70 is offered for those not requiring accommodation.

Abstract submissions are now being accepted for oral and poster presentation but make sure you submit your abstracts by the deadline on 30th June 2015.

Bursaries

A small number of bursaries are available for those with limited travel budgets and will be assessed on an individual basis. Enquire about bursaries here.

Keynote speakers

Biomaterials Science Advisory Board member Andrew Dove (University of Warwick) will be speaking along with other keynote speakers Aron Walsh (University of Bath) and Mary Ryan (Imperial College London). View the full list of invited speakers here.

For full details visit the RAMS2015 website. We hope you can join the materials science community for this fantastic event.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Paper of the Month: Rapid synthesis of ultrahigh molecular weight and low polydispersity polystyrene diblock copolymers by RAFT-mediated emulsion polymerization

Truong et al. describe the synthesis of ultrahigh molecular weight and low polydispersity polystyrene diblock copolymers by RAFT-mediated emulsion polymerisation.

aper of the month: Rapid synthesis of ultrahigh molecular weight and low polydispersity polystyrene diblock copolymers by RAFT-mediated emulsion polymerization

Ultra high molecular weight (UHMW) polymers have always been an ambitious target for synthetic polymer chemists. However, synthesising these materials using controlled radical polymerisation is challenging due to high levels of bimolecular termination and chain transfer to monomer that impede the growth of polymer chains. Monomers with higher propagation rate coefficient (kp) such as acrylamides and acrylates (and even methacrylates) have been successfully polymerised up to 106 g mol-1 but lower kp monomers (e.g. styrene) typically present broad molecular weight distributions when high molecular weight (e.g. 106 g mol-1) is targeted.

Truong et al. envisaged that a high polymerisation rate for the polymer chains would be required in order to produce well-defined UHMW polystyrene, whilst at the same time termination and side reactions would need to be minimised. The authors addressed this by employing the use of novel macromolecular chain transfer agents (CTA) in reversible addition fragmentation chain transfer polymerisation (RAFT)-mediated emulsion polymerisation. N-hydroxyethyl acrylamide (HEAA) and poly(ethylene glycol) methyl ether acrylate (PEGA) were copolymerised under judiciously selected reaction conditions to identify the most effective macrostabiliser for the emulsion polymerisation. The choice of these monomers proved crucial for the polymerisation, with PEGA conferring excellent antifouling characteristics while HEAA improves the water solubility of the macromolecular CTA and reduces partitioning of the macro-stabilisers within the styrene droplets and/or at the water/droplet interfaces. Under carefully optimised conditions, UHMW polystyrene of 106 g mol-1 could be obtained with relatively low dispersity values (<1.4) and unimodal molecular weight distributions even at near-quantitative conversions (>90%). Moreover, UV-Vis analysis confirmed the presence of the CTA, further suggesting that the reversible-deactivation radical polymerisation mechanism remained operative even to this very high conversion and molecular weight. Another interesting feature of this work is the linear relationship between particle size and molecular weight in this system, which seems to depart from the packing parameter theory, typically used to explain morphology transformations during emulsion or aqueous dispersion polymerisations. TEM analysis in all samples revealed uniformly spherical nanoparticles, even when the chain length of the polystyrene core was well above the threshold for the worm and vesicle formation. These experiments suggest that the packing parameter theory cannot be applied for all polymerisation-induced self-assembly systems and that further theoretical models are potentially required to fully understand the equilibrium morphology of soft nanoparticles.

In short, this article has overcome a longstanding challenge in the synthesis of UHMW polymers and created a new nanomaterial which offers great potential in numerous applications.

Summary points from the authors:

  1. 4,4′-Azobis(4-cyanopentanoic acid (ACPA) (free radical initiator) completely dissolves in water only after stirring for about 30 min. The stock ACPA solution should be made up fresh and not be stored for later use.
  2. To avoid the loss of styrene monomer (by evaporation) during polymerisation, there is no need to keep the emulsion polymerisation under the continuous flow of nitrogen.
  3. Samples prepared for dynamic light scattering measurements were not filtered, and as such filtration might enable a further reduction in the particle size distribution.
  4. The molar ratio of HEAA to PEGA in the macromolecular CTAs was optimised at 1 to 1. A higher molar ratio of HEAA to PEGA results in aggregation when targeting ultra-high molecular weight polystyrene. A lower molar ratio of HEAA to PEGA results in a higher portion of macromolecular CTAs partitioning within the styrene droplets.

Rapid synthesis of ultrahigh molecular weight and low polydispersity polystyrene diblock copolymers by RAFT-mediated emulsion polymerization by Nghia P. Truong, Marion V. Dussert, Michael R. Whittaker, John F. Quinn and Thomas P. Davis, Polym. Chem., 2015, 6, 3865-3874


Dr. Athina Anastasaki is a is a guest web-writer for Polymer Chemistry. She is currently a Warwick University (UK) and Monash University (Australia) research fellow working under the Monash Alliance. Visit the Haddleton group’s website for more information.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Author of the Month: Prof. Makoto Obata

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 (DPn) of ManEMA segments was constant at 33, and the DPn 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).


Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Top 10 most-read Polymer Chemistry articles – Q1 2015

This month sees the following articles in Polymer Chemistry that are in the top 10 most accessed from January – March:

Synthesis of polymeric janus nanoparticles and their application in surfactant-free emulsion polymerizations
Binh T. T. Pham, Chris H. Such and Brian S. Hawkett
Polym. Chem., 2015,6, 426-435
DOI: 10.1039/C4PY01125B

Thiol–ene “click” reactions and recent applications in polymer and materials synthesis: a first update
Andrew B. Lowe
Polym. Chem., 2014,5, 4820-4870
DOI: 10.1039/C4PY00339J

Bringing d-limonene to the scene of bio-based thermoset coatings via free-radical thiol–ene chemistry: macromonomer synthesis, UV-curing and thermo-mechanical characterization
Mauro Claudino, Jeanne-Marie Mathevet, Mats Jonsson and Mats Johansson
Polym. Chem., 2014,5, 3245-3260
DOI: 10.1039/C3PY01302B

PLA architectures: the role of branching
Stijn Corneillie and Mario Smet
Polym. Chem., 2015,6, 850-867
DOI: 10.1039/C4PY01572J

Polyglycerol coated polypropylene surfaces for protein and bacteria resistance
Maike C. Lukowiak, Sascha Wettmarshausen, Gundula Hidde, Petra Landsberger, Viola Boenke, Karsten Rodenacker, Ulrike Braun, Jörg F. Friedrich, Anna A. Gorbushina and Rainer Haag
Polym. Chem., 2015,6, 1350-1359
DOI: 10.1039/C4PY01375A

Towards being genuinely smart: ‘isothermally-responsive’ polymers as versatile, programmable scaffolds for biologically-adaptable materials
Daniel J. Phillips and Matthew I. Gibson
Polym. Chem., 2015,6, 1033-1043
DOI: 10.1039/C4PY01539H

Controlling monomer-sequence using supramolecular templates
Niels ten Brummelhuis
Polym. Chem., 2015,6, 654-667
DOI: 10.1039/C4PY01522C

Investigation into thiol-(meth)acrylate Michael addition reactions using amine and phosphine catalysts
Guang-Zhao Li, Rajan K. Randev, Alexander H. Soeriyadi, Gregory Rees, Cyrille Boyer, Zhen Tong, Thomas P. Davis, C. Remzi Becer and David M. Haddleton
Polym. Chem., 2010,1, 1196-1204
DOI: 10.1039/C0PY00100G

Synthesis and characterization of branched fullerene-terminated poly(ethylene glycol)s
Hin Chun Yau, Mustafa K. Bayazit, Piers R. J. Gaffney, Andrew G. Livingston, Joachim H. G. Steinke and Milo S. P. Shaffer
Polym. Chem., 2015,6, 1056-1065
DOI: 10.1039/C4PY01167H

Optimization of side chains in alkylthiothiophene-substituted benzo[1,2-b:4,5-b′]dithiophene-based photovoltaic polymers
Shaoqing Zhang, Mohammad Afsar Uddin, Wenchao Zhao, Long Ye, Han Young Woo, Delong Liu, Bei Yang, Huifeng Yao, Yong Cui and Jianhui Hou
Polym. Chem., 2015,6, 2752-2760
DOI: 10.1039/C5PY00071H

Why not take a look at the articles today and blog your thoughts and comments below.

Fancy submitting an article to Polymer Chemistry? Then why not submit to us today!

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Polymers curl up and take control

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

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

2015 Polymer Chemistry Lectureship awarded to Richard Hoogenboom

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…

Richard Hoogenbloom 2015 Polymer Chemistry Lectureship winner

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.

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)