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Schroot R.,Laboratory of Organic and Macromolecular Chemical IOMC | Schubert U.S.,Laboratory of Organic and Macromolecular Chemical IOMC | Schubert U.S.,Friedrich - Schiller University of Jena | Jager M.,Laboratory of Organic and Macromolecular Chemical IOMC | Jager M.,Friedrich - Schiller University of Jena
Macromolecules | Year: 2017

The metal-catalyzed polymerization of 3,6-carbazoles is explored with emphasis of end-group fidelity of the telechelic polymers. The Suzuki-Miyaura coupling polymerization using asymmetric bifunctional (AB-type) monomers was selected to circumvent the inherent polycondensation character of symmetric (AA/BB-type) monomers. Common synthetic protocols were screened to facilitate the chain growth vs step growth character during the polymerization, e.g., several activation reagents for the boronic ester and various catalytic systems and their associated reaction conditions. The reactions were analyzed in detail by size exclusion chromatography (SEC),1H NMR spectroscopy, and mass spectrometry including isotope analysis for end-group determination. It was found that the intermediate oligomers are susceptible for macrocycle formation, particularly at low concentration, while longer polymer chains continue to polymerize. The synthetic methodology was extended to utilize functionalized precatalysts and functional terminating agents in order to explore the scope of chain growth vs step growth. The concomitant formation of macrocycles was observed, which indicates the catalyst dissociation and, thus, also the polycondensation pathway. Importantly, the applied low concentration leads to trapping of the undesired nonfunctionalized chains as macrocycles, which can be readily removed from the telechelic linear polymer. In summary, the developed protocols demonstrate the versatility to prepare telechelic poly(3,6-carbazole)s via Suzuki-Miyaura coupling. The azide-decorated poly(carbazole) exemplifies the potential to serve as building blocks for further copper-mediated azide-alkyne cycloaddition reactions. © 2017 American Chemical Society.


Mansfeld U.,Laboratory of Organic and Macromolecular Chemical IOMC | Mansfeld U.,Dutch Polymer Institute | Hoeppener S.,Laboratory of Organic and Macromolecular Chemical IOMC | Hoeppener S.,Jena Center for Soft Matter | And 3 more authors.
Advanced Materials | Year: 2013

The movement of individual block copolymer micelles in free-standing films of ionic liquids is investigated by transmission electron microscopy with the aim of providing an easily accessible high-resolution imaging tool for the in situ observation of particle movement in a liquid environment. A proof of concept and first studies on the behavior of individual particles in the fluid are demonstrated. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Fruhnert M.,Karlsruhe Institute of Technology | Kretschmer F.,Laboratory of Organic and Macromolecular Chemical IOMC | Kretschmer F.,Jena Center for Soft Matter | Geiss R.,Fraunhofer Institute for Applied Solid State Physics | And 16 more authors.
Journal of Physical Chemistry C | Year: 2015

Bonding individual metallic nanoparticles at small separation distances to let them form dimers and making them available in large quantities is a key requirement for various applications that wish to exploit the tremendous enhancement of electromagnetic fields in plasmonic junctions. Although progress has been witnessed in the past concerning the fabrication of dimers mediated by rigid molecular linkers, the exact bonding mechanism remains unclear. Here, we describe the fabrication of a rigid linker molecule and demonstrate its feasibility to achieve dimers made from closely spaced metallic nanoparticles in large quantities. Although the topography of the dimers proves the success of the fabrication method, we use what we call a hypermethod characterization approach to study the optical properties of dimers from various perspectives. Measuring the surface-enhanced Raman scattering signal of the linker molecule enables direct tracing of the optical environment it perceives. By reaching a strong field enhancement in the gap of the dimers, we are able to investigate optical and geometrical properties of the linker. Moreover, upon isolation of the dimers, we use single-particle extinction spectroscopy to study the optical response of a fabricated dimer directly. Full wave numerical simulations corroborate the experimental results and provide insights into quantities which cannot be accessed directly in experiments. The ability to fabricate and to characterize rigidly linked nanoparticles will pave the way toward various plasmonic applications such as sensors, photocatalysis, and plexcitonics. © 2015 American Chemical Society.


Druzhinina T.S.,TU Eindhoven | Hoeppener S.,Laboratory of Organic and Macromolecular Chemical IOMC | Hoeppener S.,Jena Center for Soft Matter | Schubert U.S.,TU Eindhoven | And 3 more authors.
Small | Year: 2012

A reliable nanofabrication concept to engineer metallic nanometric gap structures and to incorporate silver nanoparticles within the gaps utilizing a combination of self-assembly strategies and electrochemical oxidation lithography is developed. The approach uses the differences in oxidation kinetics of n-octadecyltrichlorosilane (OTS) monolayer and bilayer structures. The processes are investigated in detail and form the basis for a new nanofabrication process. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Teichler A.,Laboratory of Organic and Macromolecular Chemical IOMC | Teichler A.,Friedrich - Schiller University of Jena | Teichler A.,Dutch Polymer Institute | Perelaer J.,Laboratory of Organic and Macromolecular Chemical IOMC | And 5 more authors.
Journal of Materials Chemistry C | Year: 2013

Inkjet printing represents a solution dispensing technique that is characterized by its non-contact, material-efficient and reproducible processing. This critical review discusses the use of inkjet printing for organic electronics with a focus on the applicability as well as the drying behavior. The nascent inkjet printing technique is compared to commonly used solution deposition methods, like spin-coating and doctor blading. Basic drying principles of inkjet printed features are understood and fundamental correlations between processing properties and film characteristics can be drawn. It is, however, a long way to gain a full understanding of the complete drying process, since the process conditions as well as the ink properties correlate in a complex relation with the final device properties. Nevertheless, inkjet printing has the potential to evolve as one of the most promising film preparation techniques in the future and has already been applied successfully in combinatorial screening workflows and for the preparation of organic solar cell devices. © 2013 The Royal Society of Chemistry.

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