Christian Hinderling

Nanoscale patterning with block copolymers

The self-assembly processes of block copolymers offer interesting strategies to create patterns on nanometer length scales. The polymeric constituents, substrate surface properties, and experimental conditions all offer parameters that allow the control and optimization of pattern formation for specific applications. We review how such patterns can be obtained and discuss some potential applications using these patterns as (polymeric) nanostructures or templates, e.g. for nanoparticle assembly. The method offers interesting possibilities in combination with existing high-resolution lithography methods, and could become of particular interest in microtechnology and biosensing.

Olefin Metathesis of a Ruthenium Carbene Complex by Electrospray Ionization in the Gas Phase

Surprisingly similar reactions in the gas phase and in solution [Eq. (a)]: The ion 1 obtained by electrospray ionization behaves in the gas phase analogously to the corresponding complex [RuCl2 (=CHPh)(PCy3 )2 ] in solution. Measured relative rates for ring-opening metathesis are interpreted under the assumption of an intramolecular π complex, which leads to an estimation of the equilibrium constant for π complexation.

Rapid Screening of Olefin Polymerization Catalyst Libraries by Electrospray Ionization Tandem Mass Spectrometry

The simultaneous screening of catalysts according to their propensity for catalyzing the polymerization of ethylene (see scheme) can be achieved with the help of electrospray ionization tandem mass spectrometry. A small (eight catalysts) library of Pd(II) complexes synthesized simultaneously in a one-pot reaction has demonstrated the efficiency of this new screening technique. This method could be widened to libraries of other olefin polymerization catalysts.

Olefinmetathese eines Ruthenium-Carben-Komplexes nach Elektrospray-Ionisierung in der Gasphase

Uberraschend ahnliche Reaktionen in der Gasphase und in Losung [Gl. (a)]: Das durch Elektrospray-Ionisation erhaltene Ion 1 verhalt sich in der Gasphase analog wie der entsprechende Komplex [RuCl2(=CHPh)(PCy3)2] in Losung. Die gemessenen relativen Geschwindigkeitskonstanten der Ringoffnungsmetathese werden unter Annahme eines intramolekularen π-Komplexes erklart; daraus last sich die Gleichgewichtskonstante der π-Komplexierung abschatzen.

Mass spectrometric assay of polymerization catalysts for combinational screening

Abstract Electrospray ionization mass spectrometry of a homogeneous Ziegler-Natta polymerization catalyzed by a Pd(II) diimine complex shows two distinct distributions of metal-bound oligomeric ions corresponding to catalytic centers which have not undergone chain transfer and those that have. A fit of two distributions by numerical integration of the kinetic equations describing the polymerization gives the absolute rates for initiation, propagation, and chain transfer in the polymerization reaction, from which the bulk polymer properties can be predicted. The mass spectrometric method requires mg quantities of catalyst, requires only a few minutes, and is suitable for both pooled and parallel screens of catalyst libraries.

Rasches Screening von Olefinpolymerisationskatalysator‐Bibliotheken durch Elektrospray‐Ionisations‐Tandem‐Massenspektrometrie

Die simultane Prufung von Katalysatoren auf ihre Eignung fur die Polymerisation von Ethylen last sich mit Hilfe der Elektrospray-Ionisations-Tandem-Massenspektrometrie durchfuhren. An einer kleinen Katalysatorbibliothek, die aus acht gleichzeitig in einer Eintopfreaktion hergestellten PdII-Komplexen bestand, wurde die Effizienz dieser neuen Screeningmethode demonstriert, die sich auf Bibliotheken anderer Olefinpolymerisations-Katalysatoren ausweiten last.

Tunable, high aspect ratio pillars on diverse substrates using copolymer micelle lithography: an interesting platform for applications

We demonstrate the use of copolymer micelle lithography using polystyrene-block-poly(2-vinylpyridine) reverse micelle thin films in their as-coated form to create nanopillars with tunable dimensions and spacing, on different substrates such as silicon, silicon oxide, silicon nitride and quartz. The promise of the approach as a versatile application oriented platform is highlighted by demonstrating its utility for creating super-hydrophobic surfaces, fabrication of nanoporous polymeric membranes, and controlling the areal density of physical vapor deposition derived titanium nitride nanostructures.

Nano-Structuring by Molecular Self-Assembly

In contrast to conventional lithography techniques which will soon hit their limits in terms of feature size and fabrication cost, recent years have seen considerable progress in the development of self-assembling nano-structured surfaces. In the work reported here, surface structures on the submicron scale have been created from polymer, copolymer, nanoparticle, and dendrimer building blocks by employing phenomena such as self-assembly, self-organization and non-equilibrium processes. This low-cost approach is expected to result in a new generation of surfaces with novel physical and chemical properties.

PAT at the Universities of Applied Sciences.

An overview of activities in the field of Process Analytical Technologies (PAT) at the Universities of Applied Sciences in Switzerland is presented.An overview of activities in the field of Process Analytical Technologies (PAT) at the Universities of Applied Sciences in Switzerland is presented.

Sustainable Chemistry at the Universities of Applied Sciences

An overview of activities in the field of sustainable or ‘green’ chemistry at the Universities of Applied Sciences in Switzerland is presented.