Fachgebiet Funktionsmaterialien

12 Items

Recent Submissions
Comparison of conventional and super-glassy polymers

Konnertz, Nora Magdalena (2017)

In the field of gas separation, polymeric membranes are favorable materials. Polymers are inexpensive compared to ceramics and metals, offer a good processability, and possess the ability to operate at large scale. The most important fact about polymeric membranes is their good selectivity. Nevertheless, most of the polymeric membranes show a strong tendency to physical aging and plasticization...

Synthesis, characterization and catalytic testing of metal tungstates as catalysts for activation of lower alkanes

Li, Xuan (2017)

The electronic and structural properties of vanadium-containing phases govern the formation of isolated active sites at the surface of these catalysts for selective alkane oxidation. This concept is not restricted to vanadium oxide. The deliberate use of hydrothermal techniques can turn the typical combustion catalyst manganese oxide into a selective catalyst for oxidative dehydrogenation of pr...

Processing, structuring, and switching of microporous polymers

Becker, Daniel (2017)

This work presents results from three different topics that stand independent from each other. If one wants to find a common denominator connecting all these topics it might be porosity. Whereas the work described in the first chapter aimed at devising new methodologies to allow nominally unprocessable polymers assume film-like morphologies, the second chapter elaborates on attempts to infuse m...

Tunable absorption and emission wavelength in conjugated microporous polymers by copolymerization

Brandt, Jessica ; Schmidt, Johannes ; Thomas, Arne ; Epping, Jan Dirk ; Weber, Jens (2011)

Conjugated, microporous polymers based on a spirobifluorene core were synthesized by Suzuki polycondensation of the tetrabromospirobifluorene with benzene diboronic acid and/or thiophene diboronic acid. The optical properties (absorption and emission spectra) and the gas sorption properties (N2 and CO2) are analyzed and discussed.

Synthesis of mesoporous composite materials of nitrogen-doped carbon and silica using a reactive surfactant approach

Paraknowitsch, Jens Peter ; Zhang, Yuanjian ; Thomas, Arne (2011)

Mesoporous composite materials of nitrogen-doped carbon and silica were synthesised in a one-step-process applying a soft templating procedure. The template used in the sol–gel synthesis of the silica is a cationic surfactant with distinct reactivity to form nitrogen-doped graphitic carbon upon heating. This reactivity is derived from the combination of the dicyanamide anion with a nitrogen-con...

Microporous sulfur-doped carbon from thienyl-based polymer network precursors

Paraknowitsch, Jens Peter ; Thomas, Arne ; Schmidt, Johannes (2011)

Porous sulfur-doped carbon was synthesised by using a thienyl-based polymer network as a precursor. The sulfur amount varies from 5–23 m% while the materials show microporosity with BET surface areas of up to 711 m2 g−1.

Nitrogen- and phosphorus-co-doped carbons with tunable enhanced surface areas promoted by the doping additives

Paraknowitsch, Jens Peter ; Zhang, Yuanjian ; Wienert, Björn ; Thomas, Arne (2013)

1-Butyl-3-methyl-pyridinium-dicyanamide (BMP-dca) is carbonised with tetra-alkyl-phosphonium-bromide additives yielding nitrogen- and phosphorus-co-doped carbons with enhanced BET surface areas promoted by the additives.

A polymer analogous reaction for the formation of imidazolium and NHC based porous polymer networks

Thiel, Kerstin ; Zehbe, Rolf ; Roeser, Jerômé ; Strauch, Peter ; Enthaler, Stephan ; Thomas, Arne (2013)

A polymer analogous reaction was carried out to generate a porous polymeric network with N-heterocyclic carbenes (NHC) in the polymer backbone. Using a stepwise approach, first a polyimine network is formed by polymerization of the tetrafunctional amine tetrakis(4-aminophenyl)methane. This polyimine network is converted in the second step into polyimidazolium chloride and finally to a polyNHC n...

Doping carbons beyond nitrogen: an overview of advanced heteroatom doped carbons with boron, sulphur and phosphorus for energy applications

Paraknowitsch, Jens Peter ; Thomas, Arne (2013)

Heteroatom doped carbon materials represent one of the most prominent families of materials that are used in energy related applications, such as fuel cells, batteries, hydrogen storage or supercapacitors. While doping carbons with nitrogen atoms has experienced great progress throughout the past decades and yielded promising material concepts, also other doping candidates have gained the resea...

Geomimetics for green polymer synthesis: highly ordered polyimides via hydrothermal techniques

Baumgartner, Bettina ; Bojdys, Michael J. ; Unterlass, Miriam M. (2014)

Inspired by geological ore formation processes, we apply one-step hydrothermal (HT) polymerization to the toughest existing high-performance polymer, poly(p-phenyl pyromellitimide) (PPPI). We obtain highly-ordered and fully imidized PPPI as crystalline flakes and flowers on the micrometer scale. In contrast to classical 2-step procedures that require long reaction times and toxic solvents and c...

Network formation mechanisms in conjugated microporous polymers

Laybourn, Andrea ; Dawson, Robert ; Clowes, Rob ; Hasell, Tom ; Cooper, Andrew I. ; Khimyak, Yaroslav Z. ; Adams, Dave J. (2014)

We discuss in detail the mechanism of formation of a highly microporous polymer, CMP-1, formed mainly via Sonogashira–Hagihara coupling. We demonstrate how the microporosity evolves with time, and discuss the importance of alkyne homo-coupling on the microporosity.

Cationic microporous polymer networks by polymerisation of weakly coordinating cations with CO2-storage ability

Fischer, Sabrina ; Schimanowitz, Aneta ; Dawson, Robert ; Senkovska, Irena ; Kaskel, Stefan ; Thomas, Arne (2014)

Microporous organic polymer networks with weakly coordinating cations in their backbone have been synthesised by metal catalysed C–C bond forming reactions. A functionalised tetraphenylphosphonium ion was synthesised and successfully used as a tecton in a co-polymerisation with tetrakis(4-bromophenyl) methane using nickel catalysed Yamamoto coupling and with triethynylbenzene in a palladium cat...