Due to their low weight, easy processability and low cost polymers are versatile materials for a wide range of applications. Nowadays, rising consumer demands and advancing technologies lead to increasingly stringent material requirements that can often not be met anymore by using simple homopolymers. Polymer nanocomposites and blends form a cost-effective and efficient approach to enhance polymer properties. In case of nanocomposites, in addition to allowing to tailor the mechanical properties, the variability in particle characteristics in terms of electrical, thermal and magnetic behavior also paves the way for the development of multifunctional polymeric materials. More in particular, the use of conductive nanoparticles can result in light and flexible materials whose electrical functionality can be tuned towards conductive, high-k low loss, sensing, actuating or electromagnetic interference (EMI) shielding applications. The latter application is widely gaining importance due to the enormous increase of the use of electronic equipment. A major challenge in this respect is the generation of a sufficient improvement of the desired property without jeopardizing mechanical properties.
This study focuses on producing polymeric systems with electrical functionality as well as improved mechanical properties by developing two-component polymeric multi-layer systems which are selectively enriched with conductive fillers.
It has been well established that polymer composites containing conductive nanoparticles can exhibit excellent electrical properties such as for example EMI shielding performance. The latter functionality results from a combination of reflection and absorption of entering electromagnetic waves by their interactions with mobile charge carriers as well as localized electric or magnetic dipoles. We will focus on the development of multi-layered polymeric systems consisting of alternating layers wich are selectively enriched with conductive fillers. Such layered structures are expected to provide enhanced EMI shielding performance due to the multiple interfaces with an impedance mismatch. In addition, the possibility to tune the microstructure (e.g. layer thickness) as well as amount of nanoparticle orientation, allows to systematically optimize EMI shielding performance and to establish structure – performance relations. To allow industrial viability of the developed materials by continuous production, layered structures will initially be generated by means of static mixers. Hence, the rheology of of the components will be essential to generate the desired structures during processing. In addition, in a later stage, the potential of novel processing techniques such as 3D printing may be explored.
Classical toughening strategies for brittle polymers such a rubber modification can improve the bulk performance considerably, as can more recent developments based on the incorporation of nanofillers with large aspect ratios, i.e. carbon nanotubes. In case of polymer films, making multilayer bi-component films is an effective toughening mechanism. When combining a tough and brittle material the performance will be intermediate between that of the two individual systems. At very thin layer thicknesses (below the critical ligament length of the system) the brittle failure mode can even be completely suppressed and a ductile failure mode can take over. When, however, combining two brittle materials the toughness can go beyond that of either of the individual systems by effectively delocalizing failure zones through the incorporation of an extra length scale (layer thickness). By combining the effect of nanofillers and thin layers the multi-layer systems produced in this project are expected to show improved, or at least comparable, mechanical performance when compared to either of their constituents.
We are looking for a candidate who meets the following requirements:
An overview of the research performed in the Polymer Technology group can be found at: www.tue.nl/pt
If interested, please submit the following documents via the apply now link below: an application letter including motivation, detailed CV including short description of work/research experience, BSc and MSc grade listings and names and contact details of at least two scientists/professors who could be approached (by us) for letters of reference. Only complete applications will be considered.
Screening of applicants will start as soon as applications are received and will continue until a suitable candidate has been found.
Application Deadline : 16 December 2015