Multiscale computational approaches to quantify energy transport process at nanoscale interfaces
Lead Research Organisation:
Imperial College London
Department Name: Chemistry
Abstract
The increasing complexity in nanoscale science is pushing the development of more sophisticated computational and theoretical methodologies for understanding the properties of nanomaterials. The proposed project revolves around the investigation of thermal transport in nanoparticle colloidal suspensions of relevance in heat transport applications (nanofluids in nanomaterials) and medical applications (thermal therapies). The computational methods will address the heterogeneous composition of the colloids by incorporating quantum (electronic) degrees of freedom, addressing their role on the interfacial thermal transport properties. A major outcome of the project will be the development of non-equilibrium simulation methods to compute thermal transport properties building on DFT, ReaxFF and classical simulation methods.
Organisations
People |
ORCID iD |
| Fernando Bresme (Primary Supervisor) | |
| Aidan Chapman (Student) |
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| EP/R513052/1 | 01/10/2018 | 30/09/2023 | |||
| 2438823 | Studentship | EP/R513052/1 | 01/10/2020 | 31/03/2024 | Aidan Chapman |
| EP/T51780X/1 | 01/10/2020 | 30/09/2025 | |||
| 2438823 | Studentship | EP/T51780X/1 | 01/10/2020 | 31/03/2024 | Aidan Chapman |
| Description | An important part of thermal transport at nanoscale interfaces is the transport in the surrounding medium. One aspect we have focused on is the polarisation of water under thermal gradients, known as thermopolarisation (TP). This is a nonequilibrium coupling effect that affects the thermal conductivity of water. The presence of thermal gradients have causes orientation of water molecules, and due to the polar nature of these molecules, an electric field in the direction of the thermal gradient is induced. We have studied the behaviour of this phenomenon for several water models and found a universal behaviour that the TP effect disappears along a line of thermodynamic states for all the models studied. The temperatures and densities at which TP disappears depends strongly on the properties of the model used, tending toward higher temperatures for models that better reproduce the experimental properties of water. As part of this work derived an equation that links the electric field generated directly to molecular properties of the water models, which can be in principle be used for other polar fluids. On the interface, we have investigated thermal transport around heated gold nanoparticles coated with two different types of ligand, one hydrophobic and one hydrophilic. Such particles are called Janus particles. We have found that just due to the differing head groups on these ligands (which are of the same length) that there is a strong temperature difference (˜ 20 K) between neighbouring ligand chains (which are a few angstroms apart) that persists all the way throughout the chain. This means that there is a strong thermal gradient present in the direction tangential to, and much stronger than, the applied thermal gradient. This work is currently under submission. During the course of the project we have developed new analysis tools for understanding, interpreting and visualising simulation results. These software tools are publicly available for anyone to use. |
| Exploitation Route | Despite how ubiquitous water is, it's unusual physical properties aren't all fully understood. A better fundamental understanding of heat transport in water has wide-ranging implications in many fields. Nanoparticles subject to infrared radiation become nanoheaters which are actively being researched as photothermal therapies for cancer treatment. In order for pharmaceutical companies to be able to predict the properties of and design particles for these purposes, a deeper understanding of thermal transport across the nanoparticle-water interface, and thus in the water itself, is needed. Thermopolarisation is a relatively newly discovered non-equilibrium coupling effect, that has not yet been measured experimentally. It is our hope that our computational research of this phenomenon inspires experimentally studies and investigations into potential applications in the energy sector. It is a fundamental physical effect that needs to be understood in order to fully understand thermal transport in polar fluids, of which water is just one example. Future work carried out during the remaining time with this funding and by other members of our group will demonstrate this to the wider scientific community. |
| Sectors | Energy,Pharmaceuticals and Medical Biotechnology |