Paper of the week: Polymer patchy colloids with sticky patches

Patchy particles (PPs) are colloidal particles with a chemically or physically patterned surface. The patchy domains may provide specific and directional interactions with other particles or surfaces and therefore PPs can self- and direct-assemble into novel suprastructures which can find applications in the delivery of drugs or other chemicals, electronic devices, photonic crystals, and sensors. Currently, the preparation of PPs mainly focuses on templating or chemical patterning, glancing angle deposition, particle lithography, capillary fluid flow, and self-assembly of pre-synthesized block copolymers. These approaches, however, are difficult to scale up because of demanding synthetic routes or owing to intrinsic limitations related to the preparation process, and therefore hamper the study and development of PPs.

Graphical abstract: Polymer patchy colloids with sticky patches

In this study, Crespy and co-workers developed an easy, low-cost and mild strategy to fabricate PPs in large quantities without using block copolymers. Polymerization-induced phase separation was found to be the reason for the formation of the PPs. The size of the patches could be easily tuned by controlling the monomer conversion or by changing the composition of the nanoparticles. The atomic force microscopy analysis revealed that the patches were sticky and embedded in a harder polymer matrix. Moreover, the patchy structure could be locked by cross-linking the sticky patches. Their approach could be extended to prepare large libraries of different PPs by choosing other polymer/monomer pairs and/or by post-functionalizing the patchy area.

Polymer patchy colloids with sticky patches by Yi Zhao, Rüdiger Berger, Katharina Landfester and Daniel Crespy Polym. Chem. 2014, 5, 365-371.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

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Announcing new Advisory Board members!

We are delighted to announce the following additions to the Polymer Chemistry Advisory Board:

These researchers are all making big advances in the field of polymer science and we are very pleased to welcome them to the team. For a full list of Polymer Chemistry board members, please click here.

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Paper of the week: Binding and supramolecular organization of homo- and heterotelechelic oligomers in solutions

Supramolecular chemistry, defined as the chemistry of noncovalent bonds (such as hydrogen bonding, π–π stacking, hydrophobic interactions, etc.), is a promising tool to create functional materials. Indeed, noncovalent bonds introduce reversibility and stimuli-responsiveness to materials. Therefore, compared to high-molecular-weight covalent polymers, processing and recycling of supramolecular polymers could be easier. Furthermore, incorporating noncovalent bonds into materials can impart original properties, such as self-healing. The simplest situation occurs when oligomers are equipped with complementary or self-complementary functional end-groups. They can in principle associate to form linear chain supramolecular polymers. The strength of the association constant controls the length of the polymer. Furthermore, supramolecular organizations at mesoscopic scales often appear and they lead to a richer and interesting behavior in comparison with classical covalent polymers. Complex mesoscopic organizations were observed both in the bulk and in solution.

Graphical abstract: Binding and supramolecular organization of homo- and heterotelechelic oligomers in solutions

In this study, Leibler and co-workers reported on the subtle influence of solvent on the organization of supramolecular polymers. They synthesized homotelechelic and heterotelechelic oligomers of poly(propylene oxide) (PPO) equipped with complementary hydrogen bonding functional ends, thymine (Thy) and diaminotriazine (DAT). In a solvent that dissociates Thy–DAT hydrogen bonds, such as DMSO, the viscosity was low for all functional telechelic oligomers. In non-dissociative solvents, the addition of functional oligomers increased the viscosity. For both the homotelechelic blends and the heterotelechelics, the viscosity in toluene was about two times higher than that in chloroform. Additionally, the Thy–DAT association constant was 22 times higher. Carbon relaxation times measured by NMR and viscosity variation for solutions of different concentrations suggest a distinct supramolecular organization in chloroform and toluene: linear and cyclic supramolecular chains in chloroform and small π-stacked objects with a PPO shell and a Thy, DAT core in toluene. One might expect that when the materials are obtained by solvent evaporation, the organization in the bulk is solvent dependent as this is often the case for ABC block copolymers.

Binding and supramolecular organization of homo- and heterotelechelic oligomers in solutions by Jessalyn Cortese, Corinne Soulié-Ziakovic and Ludwik Leibler Polym. Chem. 2014, 5, 116-125.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

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Happy holidays from Polymer Chemistry!

All of us in the Polymer Chemistry Editorial team would like to wish you all a merry Christmas and a happy new year! The Editorial office will be closed from 24th December 2013 and will reopen on 2nd January 2014.

We’re really looking forward to 2014, which will see more high quality articles from top international polymer chemists, some great themed issues and much more.

Don’t miss out on all the journal news – follow us on twitter @PolymChem and like us on Facebook!

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Poster prize winners at the 2013 International Symposium on Stimuli-Responsive Materials

Many congratulations to the winners at the 2013 International Symposium on Stimuli-Responsive Materials! 

Chosen by an independent panel, the winners were: Akira Matsumoto (Institute of Biomaterials and Bioengineering at Tokyo Medical and Dental University) for the Journal of Materials Chemistry A, B & C poster prize, Justin Poelma for Polymer Chemistry and Saemi Oh for Soft Matter (University of California, Santa Barbara). 

The symposium which focuses on the field of stimuli-responsive materials from academia, industry, and government took place in October (20 – 22) this year at the Hilton Sonoma Wine Country in Santa Rosa, CA and was co-sponsored by the Royal Society of Chemistry. 

Akira Matsumoto

Akira Matsumoto receiving his poster prize for Journal of Materials Chemistry A, B, C

Justin Poelma

Justin Poelma receiving his prize for Polmer Chemistry

Saemi Oh winning the Soft Matter poster prize

Follow the latest journal news on Twitter @PolymChem or go to our Facebook page.

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Paper of the week: All-carbon composite paper and its application in supercapacitors

Flexible papers, which utilize graphene (G) sheets as building blocks in vacuum-assisted self-assembly, have already been developed as binder-free flexible electrodes for supercapacitors due to their excellent mechanical flexibilities and electrical conductivities. Nevertheless, in most cases, the large specific surface area of the closely-packed and oriented G sheets throughout the G papers is inevitably lost which significantly reduces their potential application as supercapacitor electrodes. Thus, it is still a great challenge to develop a feasible and effective way to fabricate G-based hybrid papers as flexible electrodes with relatively high capacitances and without the sacrifice of their good cyclic stabilities.

Graphical abstract: All-carbon composite paper as a flexible conducting substrate for the direct growth of polyaniline particles and its applications in supercapacitors

In this study, Liu and co-workers reported a new strategy for the synthesis of polyaniline (PANI) nanostructures on a flexible G–carbon nanotube (G-CNT) composite paper substrate, which can be directly used as flexible electrodes possessing both electric double layer (EDL) capacitance and pseudocapacitance. The ternary hybrid paper exhibited a reversible capacity of up to 432 F g-1 at a discharge rate of 0.5 A g-1, which was much larger than that of bare G–CNT composite paper (172.4 F g-1); and its cyclic performance was dramatically enhanced, sustaining greater than 96% of its original capacitance after 600 charge–discharge cycles. Besides, the good electrical conductivity of the G–CNT composite paper provided improved conductive pathways for charge transfer at the electrodes thus resulting in superior capacitance during charge–discharge processes. Therefore, the method reported here provides a simple and efficient approach to fabricating G–CNT–PANI ternary hybrid papers with designed hierarchical nanostructures, and may be easily extended to the design of next generation high performance flexible supercapacitors.

All-carbon composite paper as a flexible conducting substrate for the direct growth of polyaniline particles and its applications in supercapacitors by Chao Zhang, Weng Weei Tjiu and Tianxi Liu Polym. Chem. 2013, 4, 5785-5792.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

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PPC 2013:Polymer Chemistry poster prize winners!

Polymer Chemistry was delighted to award three Poster Prizes at the 13th Pacific Polymer Conference, held in Kaoshiung, Taiwan between 17-22nd November 2013. The winners were:

Daisuke Aoki
‘Synthesis and Characterization of Rotaxane-Linked Graft Polymers’

Hua Deng
‘The Electrical Property-Strain Sensing Behavior of CPCs Based on Polyurethane’

Chieh-Cheng Huang
‘Hypoxia-Induced Therapeutic Neovascularization in A Mouse Model of An Ischemic Limb Using Cell Aggregates Composed of HUVECs and cbMSCs’

Congratulations to all three winners!

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Paper of the week: A CeO2/PVDC hybrid latex mediated by a phosphonated macro-RAFT agent

Combining organic matter with divided inorganic matter (nanoparticles, clays, nanofibers, etc.) is one of the main current trends to bring about new properties to polymer films. More specifically, emulsion polymerization allows the elaboration of waterborne hybrid films by incorporating mineral fillers into polymer particles to create hybrid latexes. Hence, when such latexes are directly applied as a coating, mineral entities are well distributed within the polymer matrix. Cerium oxide nanoparticles possess valuable properties, such as catalytic oxidation activity, relatively high ionic conductivity, and great potential as UV stabilizers. However, to benefit from the specific properties provided by nanoceria, a preliminary step is required in order to compatibilize the mineral phase with the polymer phase.

Graphical abstract: A CeO<sub>2</sub>/PVDC hybrid latex mediated by a phosphonated macro-RAFT agent

In their paper, Lacroix-Desmazes and co-workers reported the synthesis of a CeO2/poly(vinylidene chloride) (PVDC) hybrid latex carried out via the functionalization of CeO2 nanoparticles by reversible addition-fragmentation chain transfer (RAFT) polymerization from a phosphonated macro-RAFT agent, with very efficient formation of hybrid structures (neither free ceria nanoparticles nor free latex particles). This hybrid latex, obtained by emulsion polymerization with a reasonably high solid content (25%), represents a good candidate for the elaboration of high performance coatings. Furthermore, the authors also considered the use of such hybrid latexes as templates for the preparation of functional organic or inorganic porous materials with CeO2 nanoparticles (or other nanoparticles) evenly distributed in the porous matrix.

A CeO2/PVDC hybrid latex mediated by a phosphonated macro-RAFT agent by Jérôme Warnant, Jérôme Garnier, Alex van Herk, Pierre-Emmanuel Dufils, Jérôme Vinas and Patrick Lacroix-Desmazes Polym. Chem. 2013, 4, 5656-5663.

Julien Nicolas is a web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

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Paper of the week: Water-soluble BODIPY-conjugated glycopolymers as fluorescent probes for live cell imaging

Fluorescent probes have attracted significant attention in targeted imaging and early detection of tumor cells. Detection of real biomarkers in physiological fluid samples can dramatically impair fluorescent agent sensitivity and specificity because of biofouling and nonspecific binding. These uncertainties and drawbacks have limited the practical use of fluorescent agents in a clinical environment for medical diagnostics. Hence, the development of novel fluorescent materials with high cellular internalization efficiency, good photostability, and high specificity for tumor cell staining is in urgent demand.

Graphical abstract: Water-soluble BODIPY-conjugated glycopolymers as fluorescent probes for live cell imaging

In this article, Zhang, Li and co-workers synthesized by Atom Transfer Radical Polymerization (ATRP) a highly water-soluble, multivalent and highly specific BODIPY-conjugated glycopolymer for direct tumor cell imaging, which showed good photostability. The cell viability of BODIPY-conjugated glycopolymers against HepG2 and NIH3T3 cells was more than 80%, indicating that the glycopolymers have low cytotoxicity to living cells. Moreover, simple incubation of living cells with a BODIPY-conjugated glycopolymer led to efficient internalization into HepG2 and clear visualization in cytoplasm, due to the high brightness of BODIPY and good specificity between HepG2 and galactose as compared to NIH3T3 cells. These results suggest that BODIPY-conjugated glycopolymers have potential use as fluorescent probes in live cell imaging.

Water-soluble BODIPY-conjugated glycopolymers as fluorescent probes for live cell imaging by Zhentan Lu, Lin Mei, Xinge Zhang, Yanan Wang, Yu Zhao and Chaoxing Li Polym. Chem. 2013, 4, 5743-5750.

Julien Nicolas is a guest web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

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Paper of the week: Highly stretchable and resilient hydrogels

Hydrogels are chemically or physically cross-linked three-dimensional networks that are water insoluble but can absorb a large amount of water or biological fluids and maintain their semisolid morphology. Besides their various applications in superabsorbents, cosmetics and food, contact lenses, actuators and sensors in the materials science domain, hydrogels have become more and more attractive in artificial implants, biomedical devices, tissue engineering and regenerative medicine, etc., due to their unique properties such as similar flexibility, high water content, and molecule diffusion to natural tissues. However, unlike natural hydrogel-like bio-tissues, such as skin, muscle, cartilage, tendon, and blood-vessel which are generally strong and resilient, classic hydrogels are often brittle and have very poor mechanical performance, including low strain to break, low toughness and high strain–stress hysteresis, especially in the high strain region. Thus, design of hydrogels with good mechanical properties, such as high toughness, high stretchability and resilience, is crucially important and has drawn the extensive interest of many scientists.

Graphical abstract: Highly stretchable and resilient hydrogels from the copolymerization of acrylamide and a polymerizable macromolecular surfactant

In this paper, Huang, Guo and co-workers developed a novel micellar cross-linking copolymerization method to prepare highly stretchable and resilient hydrogels. The polymerization was based on free-radical copolymerization of water soluble acrylamide and a polymerizable macromolecular surfactant (i.e., amphiphilic polyurethane macromonomer) which can self-assemble into micelles acting as multifunctional cross-linkers. The mechanical properties, such as breaking elongation ratio, modulus and fracture toughness can be easily adjusted by varying the concentration of the polymerizable macromolecular surfactants. In addition, the mechanical energy storage efficiency (also known as resilience) was more than 96% at a strain up to 400%. These findings established a strategy for the preparation of hydrogels that combine high extendibility with excellent resilience and may greatly benefit the further use of hydrogels in tissue engineering and other soft materials research fields.

Highly stretchable and resilient hydrogels from the copolymerization of acrylamide and a polymerizable macromolecular surfactant by Mei Tan, Tingting Zhao, He Huang and Mingyu Guo Polym. Chem. 2013, 4, 5570-5576.

Julien Nicolas is a guest web-writer and advisory board member for Polymer Chemistry. He currently works at Univ. Paris-Sud (FR) as a CNRS researcher.

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