Polymer Chemistry Blog

Prof. Dr. Ir. Bruno De Geest graduated as Chemical Engineer in 2003 from Ghent University where he obtained his PhD in pharmaceutical sciences in 2006 on polyelectrolyte multilayer capsules for biomedical applications. For his PhD work he was awarded the graduate student award for pharmaceutical technology from the AAPS and the Andreas Deleenheer award from Ghent University. After 2 years of postdoctoral research at Utrecht University (The Netherlands) he returned to Ghent University at the Department of Pharmaceutics. From October 2012 onwards he is appointed as professor in Biopharmaceutical Technology.​​ Bruno De Geest has authored over 90 papers and his research group focus on the interface between materials science and life science with a particular interest in polymer chemistry, immunology and anticancer therapy.

Research website: http://brdegeest.wix.com/biopharmtech-degeest

What was your inspiration in becoming a chemist?

Chemistry offers a scientist the ability to create things using molecular scale building blocks, which appeared a very attractive concept to me. I’m a chemical engineer, thus not a hard core chemist by training. In 3^rd year at university we had organic chemistry and later on polymers taught by Filip Du Prez who was then just appointed as professor. These courses awakened a strong interest in polymer chemistry and this interest still fuels the ambition of our lab to create new materials that could hopefully be of benefit for human medicine.

What was the motivation to write your Polymer Chemistry article?

One of the main focuses of our research group in nanoparticulate vaccine delivery. While endeavoring to attach vaccine antigens to polymeric nanoparticles we noticed that the efficiency of conjugating a polymer to a protein is disappointingly low. Therefore we decided at comparing head-to-head different conjugation chemistries based on functional RAFT chain transfer agents for grafting-onto protein conjugation. The message of our paper is twofold. Firstly it gives a guide to which chemistries as more efficient than others, at least for the specific cases we have tested. Secondly, it urges the need for more efficient polymer-protein conjugation strategies.

Why did you choose Polymer Chemistry to publish your work? (DOI: 10.1039/C4PY01224K)

Polymer Chemistry has high visibility in the chemical and materials science community and publishes a high number of papers dealing with topics on controlled radical polymerization and biomedical applications. In addition, the paper will be published as part of the upcoming Emerging Investigator Issue. I’m delighted to contribute especially with this paper as it is a signature paper for our current research line.

In which upcoming conferences may our readers meet you?

I’m attending the ACS Spring Meeting in Denver in March where together with Prof. Aaron Esser-Kahn we are organizing a POLY symposium on ‘Interacting with the immune system using polymeric systems’.

How do you spend your spare times?

I’m a keen cyclist and a love to ride with my race bike trough the Flemish Ardennes. This region south of Ghent towards the Walloon border is well known for the spring cycling classics and it is a privilege to ride the same roads and climb the same cobblestone hills as the pro cyclists.

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

I think I would have studied sciences anyway, but in stead of becoming a researcher I would like be a teacher. I have always enjoyed working together with young people.

Polymer-protein conjugation via a ‘grafting to’ approach – a comparative study of the performance of protein-reactive RAFT chain transfer agents

N. Vanparijs,   S. Maji,   B. Louage,   L. Voorhaar,   D. Laplace,   Q. Zhang,   Y. Shi,   W. E. Hennink,   R. Hoogenboom and   B. G. De Geest

Abstract: Efficient polymer-protein conjugation is a crucial step in the design of many therapeutic protein formulations including nanoscopic vaccine formulations, antibody-drug conjugates and to enhance the in vivo behaviour of proteins. Here we aimed at preparing well-defined polymers for conjugation to proteins by reversible addition–fragmentation chain transfer (RAFT) polymerization of both acrylates and methacrylamides with protein-reactive chain transfer agents (CTAs). These RAFT agents contain either a N-hydroxysuccinimide (NHS) or pentafluorophenyl (PFP) ester moiety that can be conjugated to lysine residues, and alternatively a maleimide (MAL) or pyridyl disulfide (PDS) moiety that can be conjugated to cysteine residues. Efficiency of the bioconjugation of these polymers to bovine and avian serum albumin was investigated as a function of stoichiometry, polymer molecular weight and the presence of reducing agents. A large molar excess of polymer was required to obtain an acceptable degree of protein conjugation. However, protein modification with N-succinimidyl-S-acetylthiopropionate (SATP) to introduce sulfhydryl groups onto primary amines, significantly increased conjugation efficiency with MAL- and PDS-containing polymers.

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) and deputy director of the Australian Centre for NanoMedicine.

Takeshi Endo is a Professor of Molecular Engineering Institute (MEI) at Kinki University and an Emeritus Professor at Tokyo Institute of Technology (TIT). He is also Director of MEI and Vice President of Kinki University. He became an Assistant Professor at TIT in 1969, Associate Professor in 1982 and a Professor in 1986. He was Director of Chemical Resources Laboratory at TIT from 1991 until his retirement from TIT in 2000. Then he moved to Yamagata University, and became Vice President of Yamagata University until his retirement from Yamagata University in 2005. He moved to Kinki University in 2005. He was awarded the award of the Society of Polymer Science, Japan (1984), the Chemical Society of Japan Award for Creative Work (1989), and the Chemical Society of Japan Award for Technical Development (2000). From 2008, he has been an Honorary Member of the Society of Polymer Science, Japan.

Institute Website: Molecular Engineering Institute (MEI)

What was your inspiration in becoming a chemist?

I have been interested in the nature science from a young age, especially, photosynthesis that is essential to grow foods such as rice and sweet potato that I can see around my house. The interests let me to study the chemistry at university.

What was the motivation to write your Polymer Chemistry article?

Our group recently reported on synthesis of polypeptide through polycondensation of N-phenoxycarbonyl derivative of a-amino acid with the elimination of phenol and CO₂. During the course of investigation about polymethionine(oxides), we have achieve the facile route for the synthesis of well-defined poly polymethionine(oxides) in terms of molecular weigh and terminal structure through polycondensation of the corresponding urethane derivative. In addition, we found that oligo(methionine sulfoxide)-base polymer offers a excellent antifouling property against biological matters. We expect that the synthetic method could be used widely to construct polypeptide-based polymer for biomedical application.

Why did you choose Polymer Chemistry to publish your work?

Polymer Chemistry is one of the most attractive journals in the field of polymer chemistry and many readers working on the related fields will have a lot of interesting.

In which upcoming conference may our readers meet you?

I will attend the 11th International Conference on Advanced Polymers via Macromolecular Engineering (APME 2015), which is held at Yokohama in Japan from 18th to 22nd October 2015 as a member of organizing committee (Chairman). The conference is now announced at http://www.apme2015.jp/index.html. I am looking forward to seeing you at Yokohama in Japan.

How do you spend your spare times?

I enjoy watching TVs about baseball, soccer and tennis game.

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

I would choose a SF writer.

Nate studied chemistry at Michigan State University, and attended graduate school at the University of Minnesota where he worked in the laboratory of Prof. Marc A. Hillmyer on the effects of polydispersity on block polymer self-assembly. After graduating in late 2007, Nate moved to the Materials Research Laboratory at the University of California in Santa Barbara and worked in the groups of Glenn H. Fredrickson, Edward J. Kramer, and Craig J. Hawker. During nearly six years of research at the MRL, Nate published work in areas of polymer science encompassing a broad range of synthetic, physical, and theoretical topics. After UCSB, Nate became a staff scientist at Lawrence Berkeley National Laboratory in the Materials Sciences Division and became a project leader at the Joint Center for Artificial Photosynthesis. In April 2014, Nate was appointed as an assistant professor in the McKetta Department of Chemical Engineering at the University of Texas at Austin.

Nate’s research efforts are focused on creating and utilizing new functional and reactive macromolecular materials. Newer work is built on a foundation of techniques for advanced copolymer structure determination and detailed mechanistic understanding which facilitate the compositional control of structure-property-processing relationships. Specifically, we are currently engaged in gaining further understanding of compositional control in polyether materials, degradable biomedical materials, membranes for carbon capture, and understanding ion transport in polymer electrolytes and membranes.

Research group: http://lynd.che.utexas.edu/

What was your inspiration in becoming a chemist?

I always had an interest in science as a kid. I was (and still am!) very interested in geology, paleontology, and space exploration like many. My interest narrowed to chemistry with a very inspirational honors chemistry teacher in high school (Mr. John Wheeler, Batavia High School). In undergraduate, I took organic chemistry from Dr. Gregory L. Baker, a polymer chemist. I was fascinated by the possibilities of polymers, and did undergraduate research in Dr. Baker’s lab on the stereospecific synthesis of substituted lactides. This was how I got started in polymer science.

What was the motivation to write your Polymer Chemistry article?

Functional, mono-sized polymer particles are enabling to a range of applications. Our interest in this was motivated by a one very specific application, but we focused on the underlying chemistry for the article.

Why did you choose Polymer Chemistry to publish your work?

I’ve had a very positive experience with the journal, and I think it’s the right venue for rapidly reporting new developments. Additionally, I believe it reaches the right audience. As such, I’ve selected Polymer Chemistry to publish several other articles as well.

In which upcoming conferences may our readers meet you?

I will be a several upcoming conferences. I’ll be at an ECI conference on membranes in Syracuse, Italy in February, also the upcoming American Chemical Society Meeting in Denver. Additionally, I’ll be at the upcoming Gordon Research Conference on Polymers in June, and will attend the International Symposium on Ionic Polymerization in Bordeaux this July.

How do you spend your spare time?

I enjoy reading science fiction, spending time with my family, and running whenever I get a chance. I enjoy cooking and especially barbecue. Lately, I’ve been working on my central Texas style BBQ’ing skills!

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

I would probably enjoy being a scientific illustrator, or a software engineer.

A synthetic strategy for the preparation of sub-100 nm functional polymer particles of uniform diameter

Kato L. Killops,   Christina G. Rodriguez,   Pontus Lundberg,   Craig J. Hawk and   Nathaniel A. Lynd

Abstract: An amphiphilic block copolymer surfactant is used to impart peripheral surface functionality to polymer nanoparticles synthesized via emulsion polymerization. Particles ranged in size from ca. 55 nm by SEM (ca. 82 nm by DLS) to just over 200 nm. Particles displaying latent functionality were readily functionalized directly after polymerization using a fluorescent dye.

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) and deputy director of the Australian Centre for NanoMedicine.

Daniel obtained his degree in chemistry from the Johannes Gutenberg University in Mainz, Germany. During his diploma studies under the guidance of Prof. Dr. Patrick Theato, he worked on the development of photo-switchable block copolymers using controlled radical polymerization methods. He then moved to the group of Katharina Landfester at the Max Planck Institute for Polymer Research in Mainz where he received his PhD at the end of 2011. During this time he focused on the development of responsive microgels and polymeric nanoparticles for enzymatic and light-triggered release applications. In, early 2012, Daniel joined the group of Craig J. Hawker at the University of California in Santa Barbara as a postdoctoral researcher and started working on surfactant-directed block copolymer self-assembly in nanoparticles.

In his current position as project leader in the Materials Research Laboratory at UCSB, he combines the areas of block copolymer self-assembly, with his existing experience in the fields of stimuli-responsive materials and colloidal chemistry. He currently focuses on the development of functional nanomaterials from the controlled assembly of tailor-made polymeric building blocks. Among other areas, he is interested in phase-separated block copolymer nanoparticles, stimuli-responsive micro- and nano gels and new polymers and composite materials for applications in photonics, optoelectronics and thermal conductors.

What was your inspiration of becoming a chemist?

From early on, I was always interested in understanding how things around me work and constantly asked the questions, “Why is it like this?” and “How come it does that?” It was my father – a chemistry teacher – who first showed me that all these interesting phenomena could be explained by the interaction of atoms and molecules. I became hooked on the subject in high school when I learned that these physical and chemical principles could be used to develop entirely new materials of my own design. It is this process of developing new materials by combining a theoretical understanding with the handicraft of an actual experiment that still excites me and drives my research.  The ability to transform an abstract idea on paper into a reality in the lab is highly rewarding to me.

What was the motivation to write your Polymer Chemistry article?

To me, stimuli-responsive microgels have long been an interesting class of materials. Adjusting the swelling and degradation profiles via macromolecular design allows for precise tuning of their loading and release behavior. However, the utilization and efficiency of such nanoparticles in actual biomedical applications crucially depends on various structural parameters such as surface chemistry, size and size distribution. Since investigations on new responsive particles normally come with variations in these factors, accurately comparing the biological efficiency of different approaches is difficult. To overcome this limitation, I wanted to develop a synthetic platform that could investigate different response mechanisms while keeping the structural and morphological parameters constant, and the approach presented here is a first step towards realizing this goal.

Why did you choose Polymer Chemistry to publish your work?

Polymer Chemistry is a great platform for the rapid publication of studies that are not only focusing on macromolecular synthesis but also combine new polymeric materials with a variety of different research fields and applications. Since our presented research is based on combining polymer chemistry with the area of functional colloids, the interdisciplinary character of the journal makes our work accessible to a broad readership and thereby enhances its exposure.

In which upcoming conferences may our readers meet you?

Most likely, I will attend the fall ACS meeting in Boston 2015.

How do you spend your spare times?

I really like travelling and exploring new countries, cultures and foods around the world. I am especially happy if I am able to combine this with spending time in nature. I love being active outdoors and enjoy hiking, rock climbing and camping in the wilderness where simple things like sitting around the campfire can be the best reward after a long day.

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

Being a chemist, I enjoy mixing things together to make new and interesting products. If I were not a scientist, I would combine this excitement with my passion for food to become a chef. I am just not sure whether a lot of people would enjoy these “experiments”.

A robust platform for functional microgels via thiol–ene chemistry with reactive polyether-based nanoparticles

Carolin Fleischmann,   Jeffrey Gopez,   Pontus Lundberg,   Helmut Ritter,   Kato L. Killops,   Craig J. Hawker and   Daniel Klinger

We herein report the development of crosslinked polyether particles as a reactive platform for the preparation of functional microgels. Thiol–ene crosslinking of poly(allyl glycidyl ether) in miniemulsion droplets – stabilized by a surface active, bio-compatible polyethylene glycol block copolymer – resulted in colloidal gels with a PEG corona and an inner polymeric network containing reactive allyl units. The stability of the allyl groups allows the microgels to be purified and stored before a second, subsequent thiol–ene functionalization step allows a wide variety of pH- and chemically-responsive groups to be introduced into the nanoparticles. The facile nature of this synthetic platform enables the preparation of microgel libraries that are responsive to different triggers but are characterized by the same size distribution, surface functionality, and crosslinking density. In addition, the utilization of a crosslinker containing cleavable ester groups renders the resulting hydrogel particles degradable at elevated pH or in the presence of esterase under physiological 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) and deputy director of the Australian Centre for NanoMedicine.

Dr. Patrick Lacroix-Desmazes graduated in 1992 from the National School of Chemistry of Montpellier, France, and received a Master degree in Polymer Science from the University of Montpellier. He obtained his PhD degree in 1996 from the University Claude-Bernard Lyon I, under the supervision of Professor Alain Guyot in collaboration with Elf Atochem and in the frame of a European program on reactive surfactants, on the use of macromonomers as stabilizers in dispersion polymerization in polar media. After a postdoctoral research in 1997 on suspension polymerization with inorganic stabilizers at BP Chemicals in Wingles, he joined CNRS as a junior scientist working with Professor Bernard Boutevin. In 1999, he developed RITP, a promising method for controlled/living radical polymerization. He received his Habilitation Degree in 2004. He was awarded the 2004 Innovative Research ADER Award (Association for the development of Education and Research) in collaboration with Solvay. In 2009, he was distinguished as a researcher laureate from Languedoc-Roussillon and the same year he was promoted CNRS research director. Currently, he is the head of the team Engineering Macromolecular Architectures (IAM) at the Institute Charles Gerhardt in Montpellier. He is deputy president of the French Polymer Group association (GFP) and active member of the French Chemical Society (SCF). His research interests cover the mechanisms and kinetics of controlled radical polymerizations (photoiniferters, NMP, ATRP, RAFT, ITP, RITP), including in dispersed media (emulsion, dispersion, suspension polymerization), the self-assembly of polymers, the bottom-up elaboration of hybrid materials as well as the synthesis and use of polymers in liquid or supercritical carbon dioxide for the development of clean processes in unconventional media.

Link to my research group’s website: http://iam.icgm.fr/

What was your inspiration in becoming a chemist?

When I was very young, my first wish was to become a novelist. Then, during my studies I became more and more interested by sciences and my dream was to become aerospace engineer or something related to the exploration of universe! But I was not brilliant enough in math to reach this goal. And, as I also appreciated chemistry and all the mystery about it from alchemy to modern chemistry, I found that becoming chemist could be a good way to satisfy my thirst for creation. Researcher in chemistry is a great job: I like it not only on a scientific point of view but also because it is an excellent way to make new friends all over the world and share our cultures.

What was the motivation to write your Polymer Chemistry article?

We have been working on double hydrophilic block copolymers (DHBC) since a few years and with some colleagues of our institute we have shown that such copolymers could be nicely used as structure-directing agents in the elaboration of hybrid mesoporous silica materials (paper here). In the present article, we wanted to detail the synthesis of such copolymers and to show how a platform of DHBC with different characteristics (cationic, anionic, pH- or T-stimuli responsive) could be efficiently produced. Many papers appear in the literature on this topic but quite few are giving and discussing the very details that make the synthesis more or less challenging, so we tried to emphasize on such details.

Why did you choose Polymer Chemistry to publish your work?

Polymer Chemistry is a journal with a good audience and fast dissemination and the reviewing process is usually constructive. For this article, we really took our time to fully answer the comments of the referees. This journal is a leading one in chemistry and the editorial and production team is well organized.

In which upcoming conferences may our readers meet you?

My next conference will probably be the 3^rd International Symposium on Green Chemistry to be held in La Rochelle on May 3-7 2015. I will present our latest results on polymer-assisted clean processes in supercritical carbon dioxide.

How do you spend your spare times?

I like hiking in general and in the mountains when I have enough time, contemplating nature, far from the rushing modern life. I also enjoy swimming, running and biking with my 14 and 16 years old girls. I love travelling and discovering new countries and share other cultures with my family.

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

I think I would create a new type of job: itinerant teacher. Instead of the students coming to the teacher, the teacher would visit the students worldwide to share the knowledge and cultures.

Asymmetric neutral, cationic and anionic PEO-based double-hydrophilic block copolymers (DHBCs): synthesis and reversible micellization triggered by temperature or pH

Maël Bathfield,   Jérôme Warnant,   Corine Gérardin and  Patrick Lacroix-Desmazes

The syntheses of three poly(ethylene oxide)-based (PEO) double-hydrophilic block copolymers (DHBCs) of different second block nature (thermosensitive poly(N-isopropylacrylamide) (PNIPAM) block, anionic poly(vinylbenzyl phosphonic di-acid) block, and cationic poly(vinylbenzyl triethyl ammonium chloride) block) are described. The synthesis strategy depends on the synthesis of a single 5kD-PEO-based macro-chain transfer agent that is able to control the RAFT polymerizations of various functional monomers. Low molecular weights of the second block were targeted to obtain asymmetric structures for the DHBCs. Their ability to form micelles under appropriate conditions (specified temperature, pH and nature of the auxiliary of micellization) and the reversibility of the micellization process were checked. Finally, a nanostructured hybrid silica material was obtained using the PNIPAM-based copolymer as a structure-directing agent (SDA), which yielded well-organized mesoporous silica after template removal.

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) and deputy director of the Australian Centre for NanoMedicine.

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!

Dr. Antoine Debuigne is currently a Research Associate of the National Fund for Scientific Research (F.R.S. – FNRS) at the University of Liege, Belgium. He graduated in 1999 from the University of Namur, Belgium, following a master’s thesis in organic chemistry. In 2004, he obtained his Ph.D. degree from the Center for Education and Research on Macromolecules (CERM), University of Liege, Belgium, directed by Prof. R. Jérôme. He then moved to the University of Toronto, Canada, and conducted post-doctoral research in Prof. M.K. Georges’ group, who pioneered the field of controlled radical polymerisation. In 2006, he returned to the CERM in Liege as a FNRS post-doctoral researcher and was promoted to FNRS Research Associate in 2010 in the same group. His research interests include controlled radical polymerisation, organometallic chemistry, macromolecular engineering and emulsion polymerisation.

To find out more about the CERM please follow the link.

What was your inspiration in becoming a chemist?

Several members of my family are scientists, even chemists, so “I fell early into chemistry”. During my scholarship, I also met excellent science teachers who taught me how important science is for understanding the world we are living in. So, I decided to make it my job. Among all scientific fields, I chose chemistry because it appeared to me as a central and practical discipline.

What was the motivation to write your Polymer Chemistry article?

Recent progress in controlled radical polymerisation (CRP) is impressive. The increasing precision and complexity of polymer structures achievable and their use in a broad range of applications might suggest that challenges in CRP may soon be non-existent. However, this is not the case and efforts still need to be expended to improve the existing tools and discover new ones in order to finely tune polymer properties. This is what the present Polymer Chemistry article is about. Indeed, poly(N-vinylcaprolactam) (PNVCL) combines valued properties such as water solubility, biocompatibility and thermo-responsiveness, but has not reached its full potential so far due to limitations in macromolecular engineering techniques. Nevertheless, the Organometallic-Mediated Radical Polymerisation (OMRP), a CRP method developed in the lab for many years, permitted us to produce a series of well-defined N-vinylcaprolactam and N-vinylpyrrolidone-based copolymers including statistical, diblock and triblock copolymers, having single or dual thermo-responsive behaviour in water. The high level of control afforded by OMRP allowed us to highlight the crucial impact of the copolymer composition, block length and architecture on the cloud point temperature of each segment and to tune their multistep assembly behaviour. The reversible temperature triggered assembly of such block copolymers in water opens new perspectives in the field of stimuli-responsive encapsulation/release applications.

Why did you choose Polymer Chemistry to publish your work?

My co-authors and I chose Polymer Chemistry because it provides high quality manuscripts in polymer science to a broad audience. This last aspect was crucial in the selection of a journal because our contribution contains progress in both macromolecular engineering and characterisation of the thermal response of copolymers in solution.

In which upcoming conferences may our readers meet you?

My agenda is still unclear for the next few months but I really would like to attend the Gordon Research Conference on Polymers, South Hadley, MA, USA  in June 2015.

How do you spend your spare time?

I enjoy spending time with my 6-year old son, friends and relatives. I also like reading novels and practice more and more photography. In this respect, I warmly recommend a visit to the photography museum of Charleroi in Belgium.

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

Maybe architect because this profession requires both technical and artistic skills. Having said that, I have no regret at all.

One of my pictures. “Building reflected on water”

Double thermo-responsive hydrogels from poly(vinylcaprolactam) containing diblock and triblock copolymers

Jean-Michel Thomassin,  Kevin Mathieu,   Anthony Kermagoret,   Charles-André Fustin,   Christine Jérôme and   Antoine Debuigne

The thermally-induced gelation and gel properties of concentrated aqueous solutions of double thermoresponsive poly(N-vinylamide)-based di- and triblock copolymers are studied by rheology. The copolymers under investigation, prepared by cobalt-mediated radical polymerisation and coupling reactions, are composed of poly(vinylcaprolactam) (PNVCL) blocks and of a statistical poly(vinylcaprolactam-stat-vinylpyrrolidone) segment with a cloud point temperature (T_CP) higher than that of PNVCL. Heating the di- and triblock solutions beyond the first phase transition temperature favours gel formation while heating above the second T_CP leads to opaque gels without macroscopic demixing. Moduli of the triblock hydrogels are systematically higher than those of the corresponding diblocks, even above the second transition. Rheological data suggest distinct micellar structures for each copolymer architecture: densely packed micelles of diblocks and 3-D networks of bridged micelles for triblocks. Strain sweep experiments also emphasize the positive effect of the micelle bridging on the elasticity and stability of the hydrogels. The formation and properties of the obtained gels are also shown to depend on the copolymer concentration, block length, and composition. Addition of salt also allows us to tune the phase transition temperatures of these double thermoresponsive hydrogels.

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).