Theodorus Tervoort

Microcutting Materials on Polymer Substrates

The production of micrometer and sub-micrometer features over large areas for use in electronic and optical structures remains challenging, particularly as requirements extend beyond traditional electronic materials to ceramics and polymers. We demonstrate that the technique of microcutting allows patterning of such structures on polymer substrates of these materials as exemplified by the ceramic indium tin oxide (ITO) and the conducting polymer poly(3,4-ethylenedioxythiophene) (PEDOT). Given the brittleness of most ceramics such as ITO, this is very unexpected, but we find no evidence for microcracking and find high electrical conductivities in narrow tracks (∼2.5 μm) that are separated by less than 500 nm. The micrometer-scale patterns also act as very efficient alignment layers for liquid crystals (LCs), and allow complex alignment patterns.

Solid-solution formation and phase segregation in binary systems of homologous extended-chain perfluorinated alkanes

Using differential scanning calorimetry (DSC) and X-ray analysis it is shown that binary systems of perfluorinated alkanes form solid solutions or exhibit eutectic phase behaviour, depending on their difference in chain length. A simple model, which successfully correlated experimental results for this aspect of phase behaviour of binary n-alkane systems, is demonstrated to quantitatively describe the behaviour of perfluorinated alkanes as well. From the model parameters and experimental observations, it appears that, at equal number of carbon atoms, binary perfluorinated alkane systems allow for a larger chain difference than their hydrogenated analogues, before eutectic phase behaviour sets in.