Studying Carbon Nanotubes on the Mesoscale: Physical Properties and Emergent Phenomena
Lead Research Organisation:
University of Cambridge
Department Name: Materials Science & Metallurgy
Abstract
Since the first characterisation of carbon nanotubes (CNTs) by Iijima in 1991, a considerable amount of research has been conducted on their physical properties and applications. While CNTs as a material have shown promise, an inability to generate industrial quantities has limited their practical application. Among a variety of processes proposed to address this problem, the Floating Catalyst Chemical Vapour Deposition (FCCVD) process is of considerable academic and industrial interest for bulk CNT material production. The process produces dilute CNT network materials referred to as aerogels which can then be processed into continuous CNT fibres and composite materials. Developing an understanding of how aerogels and other CNT structure form during FCCVD and any subsequent process is critical in optimising the manufacturing process and tailoring material properties to specific applications.
The aim of the PhD is to study the formation and physical properties of CNT structures using computational methods. In order to achieve suitable computation times, adaptive mesoscale methods are used which enable simulations of systems containing hundreds of millions of carbon atoms. These simulations can also be used to measure effective physical properties of the resulting material, such as mechanical resistance to load or electrical and thermal conductivities. Of particular interest are phenomena that emerge due to different microstructures rather than the properties of the individual CNTs. Examples are the transition from isolating to electrically conductive behaviour called electrical percolation as well as scaling of the electrical conductivity from individual CNTs to CNT fibres or bulk materials.
The aim of the PhD is to study the formation and physical properties of CNT structures using computational methods. In order to achieve suitable computation times, adaptive mesoscale methods are used which enable simulations of systems containing hundreds of millions of carbon atoms. These simulations can also be used to measure effective physical properties of the resulting material, such as mechanical resistance to load or electrical and thermal conductivities. Of particular interest are phenomena that emerge due to different microstructures rather than the properties of the individual CNTs. Examples are the transition from isolating to electrically conductive behaviour called electrical percolation as well as scaling of the electrical conductivity from individual CNTs to CNT fibres or bulk materials.
Publications
Kloza P
(2020)
Freely Suspended Semiflexible Chains in a Strong Aligning Field: Simple Closed-Form Solutions for the Small-Angle Approximation
in Macromolecular Theory and Simulations
Kateris N
(2020)
From Collisions to Bundles: An Adaptive Coarse-Grained Model for the Aggregation of High-Aspect-Ratio Carbon Nanotubes
in The Journal of Physical Chemistry C
Issman L
(2022)
Highly Oriented Direct-Spun Carbon Nanotube Textiles Aligned by In Situ Radio-Frequency Fields.
in ACS nano
Studentship Projects
Project Reference | Relationship | Related To | Start | End | Student Name |
---|---|---|---|---|---|
EP/R513180/1 | 30/09/2018 | 29/09/2023 | |||
2280508 | Studentship | EP/R513180/1 | 30/09/2019 | 29/09/2022 | Philipp Kloza |
Description | We developed a model that describes the behaviour of carbon nanotubes in the presence of static and alternating electric fields. In the context of our work, electric fields are used to align carbon nanotubes, such that their mechanical properties can be exploited more efficiently, yielding stronger materials. We found key differences between static and alternating fields, and were able to attribute these differences to a physical effect we call z-pinch stiffening. The effect is due to electromagnetic interactions inside the nanotubes arising from electrical currents forming when alternating electric fields are applied. The model is able to describe how carbon nanotube alignment changes with different external parameters such as temperature, electric field strength and field frequency. |
Exploitation Route | Our model can inform researchers and engineers on how to improve the synthesis process of carbon nanotubes in an effort to further improve their material properties. Subsequently, carbon nanotube materials with better mechanical or electrical properties can be used in a multitude of sectors. |
Sectors | Aerospace Defence and Marine Energy Environment Manufacturing including Industrial Biotechology |
Title | Mesoscopic Lennard-Jones potential for carbon nanotube systems |
Description | The potential is a C++ implementation of a coarse-grained Lennard-Jones potential in the LAMMPS molecular dynamics software package. The potential can be used to model large mesoscale systems of carbon nanotubes, e.g. to study their structural or mechanical properties. |
Type Of Technology | Software |
Year Produced | 2022 |
Open Source License? | Yes |
Impact | The potential allows for straightforward and fast simulations of large carbon nanotube systems. It is the first open-source implementation of the potential and thus enables researchers to study a multitude of problems in the field of one-dimensional nanomaterials (such as carbon nanotubes) without having to implement the potential themselves. |
URL | https://docs.lammps.org/pair_mesocnt.html |