Laboratory of Macromolecular and Organic Materials – LMOM

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Highlights of Scientific Achievements

Carbon Nanomaterials by Room Temperature Carbonization of Hexayne Amphiphiles

Carbon nanomaterials offer intriguing perspectives for applications in emerging technologies such as hydrogen storage, lithium storage, transition metal free catalysis, or photovoltaics. A better control over surface chemistry, carbon structure, nanoscopic morphology, and microstructure would be desirable but has so far been excluded by the high-energy processes typically employed for their preparation. We have developed amphiphiles with “carbon-only” hexayne segments that serve as reactive molecular carbon precursors. This approach has enabled us for the first time to perform carbonizations at room temperature, preserve the surface chemistry introduced with the employed precursors, and tailor the nanoscopic morphology using known supramolecular self-assembly concepts. In this way, we have prepared carbon nanocapsules with a controlled diameter from aqueous dispersions of self-assembled vesicles, as well as carbon sheets with lateral dimensions of many centimeters, a carbon structure resembling reduced graphene oxide, and amphiphilic surfaces.

Key Publications

  • 131 S. Schrettl, C. Stefaniu, C. Schwieger, G. Pasche, E. Oveisi, Y. Fontana, A. Fontcuberta i Morral, J. Reguera, R. Petraglia, C. Corminboeuf, G. Brezesinski, H. Frauenrath, Functional Carbon Nanosheets Prepared from Hexayne Amphiphile Monolayers at Room Temperature, Nature Chem., 2014 , 6, 468-476,
  • 1213 R. Szilluweit, T. N. Hoheisel, M. Fritzsche, B. Ketterer, A. Fontcuberta i Morral, D. Demurtas, V. Laporte, R. Verel, S. Bolisetty, R. Mezzenga, H. Frauenrath, Low-Temperature Preparation of Tailored Carbon Nanostructures in Water, Nano Lett., 2012 , 12, 2573-2578
Further Publications. Org. Lett., 2008

Hydrogen-Bonded Organic Electronic Materials with 1D and 2D Nanostructures

Organic nanowires are model systems for the investigation of charge transport in organic semiconductors under nanoscopic confinement, and may serve as potential building blocks for integrated circuits in the future. However, reliable structure-property relationships between the molecular parameters, the intermolecular π–π interactions, the nature of the charge carriers, and macroscopic transport properties are scarce. We have now established an approach to prepare organic nanowires that consist of exactly one stack of π-conjugated chromophores with a tight intermolecular correlation of the latter due to their hydrogen-bonded substituents. These nanowires exhibit an unprecedented light-induced “self-doping”, resulting in exceptionally high charge densities of up to 107 cm–1 along the nanowires, and band-like transport properties. Macroscopic transport measurements show high current densities, and a clear relation to spectroscopic features of the nanowires. We have meanwhile transferred the concept of using hydrogen-bonded substituents to crystalline quaterthiophene thin films and observed the highest field-effect mobilities reported for this class of organic semiconductors.

Key Publications.

  • 1114 L. Tian, R. Szilluweit, R. Marty, L. Bertschi, M. Zerson, E.-C. Spitzner, R. Magerle, H. Frauenrath, Development of a Robust Supramolecular Method to Prepare Well-Defined Nanofibrils from Conjugated Molecules, Chem. Sci., 2012 , 3, 1512-1521
  • 1055 R. Marty, R. Szilluweit, A. Sanchez–Ferrer, S. Bolisetty, J. Adamcik, R. Mezzenga, E. C. Spitzner, M. Feifer, S. N. Steinmann, C. Corminboeuf, H. Frauenrath, Hierarchically Structured Microfibers of ‘Single Stack’ Perylene Bisimide and Quaterthiophene Nanowires, ACS Nano, 2013 , 7, 8498–8508
  • 914 L. Tian, R. Szilluweit, R. Marty, L. Bertschi, M. Zerson, E.-C. Spitzner, R. Magerle, H. Frauenrath, Development of a Robust Supramolecular Method to Prepare Well-Defined Nanofibrils from Conjugated Molecules, Chem. Sci., 2012 , 3, 1512-1521
In revision. Nature Mater., , J. Am. Chem. Soc.,
Further publications. Chem. Eur. J., ASAP , J. Phys. Chem. B, 2014 , ACS Macro Lett., 2012

Hierarchically Structured Supramolecular Elastomers

Supramolecular networks that make use of specific non-covalent interactions furnish elastomer materials with superior processing and self-healing properties. However, they typically lack the hierarchical structure formation observed in biomaterials that could be employed to tailor their mechanical properties. We prepared novel supramolecular materials based on oligopeptide-modified polymers that gave rise to “interpenetrating supramolecular networks”, that is, topologically independent networks with non-covalent interactions as network nodes. These materials displayed excellent energy dissipation because, when varying the frequency of an applied shear strain, one network underwent a solid-fluid transition while the other one showed a fluid-solid transition. We have meanwhile demonstrated the universal nature of this effect, independent of the chemical structure of the components that form the interpenetrating supramolecular networks. Since the observed properties are hence solely due to network connectivity, our materials can be regarded as the first example of a “supramolecular metamaterial”.

Key Publications.

  • 853 E. Croisier, S. Liang, T. Schweizer, S. Balog, M. Mionic, R. Snellings, J. Cugnoni, V. Michaud, H. Frauenrath, A Toolbox of Oligopeptide-Modified Polymers for Tailored Elastomers, Nature Commun., 2014 , 5, 4278
Further publications. one more key publication submitted.

Reactions in Organized Media

Chemical reactions in single crystals often occur with perfect product selectivity. We employed this paradigm to prepare the first alternating polydiacetylene copolymers, and we reported an unusual dimerization of bromodiacetylenes that was the first complex multistep reaction performed in a single-crystal.

Key Publications.

  • 754 T. N. Hoheisel, S. Schrettl, R. Marty, T. K. Todorova, C. Corminboeuf, A. Sienkiewicz, R. Scopelliti, W. B. Schweizer, H. Frauenrath, A Multistep Single-Crystal-to-Single-Crystal Bromodiacetylene Dimerization, Nature Chem., 2013 , 5, 327–334
  • 627 R. Xu, W. B. Schweizer, H. Frauenrath, Soluble Poly(diacetylene)s Using the Perfluorophenyl-Phenyl Motif as a Supramolecular Synthon, J. Am. Chem. Soc., 2008 , 130, 11437-11445
  • 536 R. Xu, V. Gramlich, H. Frauenrath, Alternating Diacetylene Copolymer Utilizing Perfluorophenyl-Phenyl Interactions, J. Am. Chem. Soc., 2006 , 128, 5541-5547
  • 429 H. Frauenrath, E. Jahnke, A General Concept for The Preparation of Hierarchically Structured π-Conjugated Polymers, Chem. Eur. J., 2008 , 14, 2942-2955

Multiple-Helical π-Conjugated Polymers

Biopolymers typically exhibit dynamic folding into complex hierarchical structures. We prepared the first synthetic, π-conjugated polymer that exhibited a multiple-helical quaternary structure of polymer chains and underwent partially reversible unfolding/refolding processes.

Key Publications.

  • 328 J. Weiss, E. Jahnke, N. Severin, J. P. Rabe, H. Frauenrath, Consecutive Conformational Transitions and Deaggregation of Multiple-Helical Poly(diacetylene)s, Nano Lett., 2008 , 8, 1660-1666
  • 232 E. Jahnke, N.Severin, P. Kreutzkamp, J. P. Rabe, H. Frauenrath, Molecular Level Control over Hierarchical Structure Formation and Polymerization of Oligopeptide-Polymer Conjugates, Adv. Mater., 2008 , 20, 409-414
  • 137 E. Jahnke, I. Lieberwirth, N. Severin, J. P. Rabe, H. Frauenrath, Topochemical Polymerization in Supramolecular Polymers of Oligopeptide-Functionalized Diacetylenes, Angew. Chem. Int. Ed., 2006 , 45, 5383-5386

Further publications. Chem. Eur. J., 2009 , Chem. Eur. J., 2008 , Macromol. Rapid Commun., 2008 , Macromol. Biosci., 2007
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Contact Information

Laboratory of Macromolecular and Organic Materials

Address
EPFL–STI–IMX–LMOM
MXG 037
Station 12
1015 Lausanne
Switzerland
Phone
+41 21 693 7395
Email
lmom@epfl.ch

News & Highlights

  • - Reuben Yeo joined the group as a postdoc.
  • - Alexis Claveau joined the group as a PhD Student.
  • - Nicolas Candau joined the group as a postdoc.