This PhD opportunity will be based at Heriot-Watt University, Edinburgh.Please contact Prof David Bucknall ([email protected]) for further details.Multifunctional subsea cables are widely used in infrastructure connections between land-based facilities, surface ships or platforms to assets on the seabed. The cables can have multiple operational roles (or combination of roles), including high power transmission, fluid transport and communications. These single or multi-functional cables utilize a range of polymers where their dielectric performance, as well as mechanical properties, such as modulus, wear resistance etc. are essential for the operational functionality in often challenging subsea conditions.In this project we will explore high performance engineering plastics and elastomers and how the use of nanomaterials can potentially improve the dielectric behaviour of the polymer without compromising their mechanical properties. We will employ a combination of multiscale modeling together with a detailed experimental program, which will both validate the modeling but also provide insight into the polymer behaviour. The goal of the project will be to develop a molecular level understanding of polymer nanocomposites that will enable a predictive capability of their dielectric and thermo-mechanical properties. The multiscale modeling will build upon fully atomistic molecular dynamics (MD) modelling to allow simulation of the semi-crystalline structures (with realistic levels of amorphous and crystalline phases) of the polymers. This molecular modelling will also allow inclusion of a range of nanoparticles (NPs). The atomistic MD models will be used as the input to larger scale modeling such as multi-scale generalized methods of cells (MSGMC) micromechanic code to enable macroscopic properties of the individual nanocomposites to be calculated. A range of NPs will be studied with different chemistries (i.e. dielectric characteristics), surface functionalities and concentrations and the dependence on both dielectric behaviour and thermo-mechanical properties established. Based on the outcome of the modeling, promising nanocomposites will be evaluated experimentally. Samples will be prepared using small-scale melt processing methodologies to simulate full-scale industrial compounding and melt processing operations. Critical process parameters will be evaluated, in particular melt rheology behaviour and the impact of the NP inclusions. The injection molded polymer nanocomposites will be evaluated for their dielectric breakdown strength, as well as thermos-mechanical properties including modulus (from stress-strain measurements), thermal properties (incl. Tg, Tm), and creep. The properties of the polymer nanocomposites will be corelated against key metrics such as the degree of dispersion of the NPs (related to the surface functionalization), their effect on the polymer crystallinity and concentration. Results from the experimental measurements will be compared to modeling results and corrections to the modeling processes adapted as necessary.The end goal of the project will be the establishment of a robust multi-scale model for nanoparticle containing polymer nanocomposites, that has been validated against a detailed series of experiments. The combined modeling and experimental results will provide a robust predictive capability that can potentially be used for a range of engineering plastic nanocomposites.The Industrial CASE project will be co-supervised by experimental and modeling experts from both Heriot-Watt University and Siemens Energy. This project is a fully funded 4 year CASE PhD studentship during which the successful candidate will spend around 3 months placement at Siemens Energy at their facilities either in Ulverston or Aberdeen. Additionally, the CASE studentship comes with a £4k p.a. top up to the standard PhD stipend as well as additional funding for consumables, small equipment, travel and conference attendance.