Professor Kyriakos Porfyrakis BSc, MSc, DPhil, FRSC

Mechanical & Chemical Engineering Portfolio Leader

Materials and Chemical Engineering R&E Group Leader

2016 Fellow of the Royal Society of Chemistry (FRSC). The FRSC title is given to people who "have made an outstanding contribution to the advancement of the chemical sciences; or to the advancement of the chemical sciences as a profession; or have been distinguished in the management of a chemical sciences organisation".

2013-2018 EPSRC Fellowship, Department of Materials, University of Oxford under the theme "Manufacturing the future".

2005-2007 Merit Award by the Department of Materials, University of Oxford, for significant contribution to the work of the Department.

2005 Alan Glanvill Award by the Institute of Materials, Minerals and Mining for a published work of particular merit in the field of polymers.

1997-1999 Waterson Scholarship by St. Anne's College, University of Oxford.

1996-1999 EPSRC Studentship tenable at University of Oxford, Department of Materials.

Editor for the Journal "Molecules " (ISSN 1420-3049)

Fellow of the Royal Society of Chemistry.

Professor Porfyrakis has nearly 20 years of cutting edge research in the fields of carbon nanomaterials. His expertise is in the synthesis and chemical functionalization of carbon nanomaterials such as endohedral fullerenes, carbon nanotubes and graphene. Endohedral fullerenes and their chemically functionalised derivatives are a highly promising class of nanomaterials in the true sense of the term as they are molecular structures with a diameter of approximately 1nm.

His research vision is to exploit the properties of endohedral fullerenes in order to develop novel functional materials for use in three crucial fields of research: nanoelectronics(quantum information, spintronics and atomic clocks), energy (organic photovoltaics, batteries) and nanomedicine (magnetic contrast agents, spin probes for superoxide radicals and oximetry agents).The Porfyrakis laboratory is in a unique position in the UK and one of only a handful of research centres in Europe that is capable of controlling the synthesis, purification, characterisation and functionalization of endohedral fullerenes that contain both metallic (metallofullerenes) and non-metallic N@C₆₀ and N@C₇₀ elements. The Porfyrakis laboratory has synthesised a series of endohedral metallofullerene species including, for the first time, two isomers of Nd@C₈₂with C_2v and C_s symmetries as well as a bimetallic Pr-metallofullerene that has attractive optical properties. Professor Porfyrakis was part of the team that developed a methodology for using single-walled carbon nanotubes as reaction vessels. It was included in the 2006 Guinness Book of Records as the world's smallest test tube with a volume of two zeptolitres, or 2*10^-21litres. He is one of the most prolific authors in the field of endohedral fullerenes and is ranked in the top-20 authors in the world in terms of number of publications (source: Web of Science). Indeed, he is the highest ranked author within the UK in this field.

Key funded projects

Professor Porfyrakis has attracted over £2.5 M in funding as a Principal Investigator and another £7.5 M as Co-Investigator. Some current and recent research projects are described below:

EP/R031975/1 EPSRC "Sustainable and industrially scalable ultrasonic liquid phase exfoliation technologies for manufacturing 2D advanced functional materials (EcoUltra2D)", 1 October 2018 to 30 September 2021. Funding: £ 570,384 (Co-Investigator)

Project summary:Two-dimensional materials will play a pivotal role in the 21^st century technology. We propose a clean, environment friendly and productive technology of 2D materials exfoliation that does not require the use of polluting and toxic solvents and surfactants; and uses pure water instead. To make it possible we will put the power of ultrasonic cavitation and streaming in the centre of the technology and will make its informed use through a unique, advanced and thorough study of the underlying mechanisms. Manufacturing of 2D materials presents currently a great challenge, from the viewpoints of scalability, productivity, sustainability, and environment. The time is right to establish the best way of manufacturing that will be scalable, eco-friendly and productive. Currently available technologies are based on chemical mechanisms that involve harmful and environment polluting solvents and surfactants, facilitated by the application of external fields such as shearing or ultrasonication (US). We propose to overturn the current paradigm that is focused on physico-chemical exfoliation and put the US processing in the limelight. The scientific novelty lies in establishing the mechanisms of US exfoliation through most advanced and bespoke techniques. The technological step-change advance is in developing a scalable and environment friendly process with the focus on minimising the amount of specialised, expensive and harmful additions, and minimising the processing time with simultaneous increase in the yield and size of 2D sheets.

EP/R029229/1 EPSRC "From nanoscale structure to nanoscale function (NS2NF)", 1 May 2018 to 30 April 2023. Funding: £1,530,594 (Co-Investigator)

Project summary: As we gain ever-greater control of materials on a very small scale, so a new world of possibilities opens up to be studied for their scientific interest and harnessed for their technological benefits. In science and technology nano often denotes tiny things, with dimensions measured in billionths of metres. At this scale structures have to be understood in terms of the positions of individual atoms and the chemical bonds between them. The flow of electricity can behave like waves, with the effects adding or subtracting like ripples on the surface of a pond into which two stones have been dropped a small distance apart. Electrons can behave like tiny magnets, and could provide very accurate timekeeping in a smartphone. Carbon nanotubes can vibrate like guitar strings, and just as the pitch of a note can be changed by a finger, so they can be sensitive to the touch of a single molecule. In all these effects, we need to understand how the function on the nanoscale relates to the structure on the nanoscale.
This requires a comprehensive combination of scientific skills and methods. First, we have to be able to make the materials which we shall use. This is the realm of chemistry, but it also involves growth of new carbon materials such as graphene and single-walled carbon nanotubes. Second, we need to fabricate the tiny devices which we shall measure. Most commonly we use a beam of electrons to pattern the structures which we need, though there are plenty of other methods which we use as well. Third, we need to see what we have made, and know whether it corresponds to what we intended. For this we again use beams of electrons, but now in microscopes that can image how individual atoms are arranged. Fourth, we need to measure how what we have made functions, for example how electricity flows through it or how it can be made to vibrate. A significant new development in our laboratory is the use of machine learning for choosing what to measure next. We have set ourselves the goal that within five years the machine will decide what the next experiment should be to the standard of a second-year graduate student.

The Platform Grant renewal 'From Nanoscale Structure to Nanoscale Function' will provide underpinning support for a remarkable team of researchers who bring together exactly the skills set which is needed for this kind of research. It builds on the success of the current Platform Grant 'Molecular Quantum Devices'. This grant has given crucial support to the team and to the development of their careers. The combination of skills, and the commitment to working towards shared goals, has empowered the team to make progress which would not have been possible otherwise. For example, our team's broad range of complementary skills were vital in allowing us to develop a method, now patented, for making nanogaps in graphene. This led to reproducible and stable methods of making molecular quantum devices, the core subject of that grant. The renewal of the Platform Grant will underpin other topics that also build on achievements of the current grant, and which require a similar set of skills to determine how function on the nanoscale depends on structure on the nanoscale.

EP/P033490/1 EPSRC "Interlocked fullerene and endohedral metallofullerene hosts for molecular machine-like sensing", 23 November 2017 to 15 January 2021. Funding: £875,651 (Co-Investigator)

Project summary: Mechanically interlocked molecules such as rotaxanes, which resemble a molecular abacus with rod-like molecules passing through one or more rings and catenanes, which are two or more interpenetrating rings, are firmly established entities in the field of nanoscale molecular machines because of their ability to undergo controlled and reversible molecular motion through changes in the relative positions of their constituent parts. The inherent dynamics of such molecules can be controlled by light, electrochemical and chemical-based stimuli. This proposal aims to exploit their unique topological interlocked host cavities to recognize guest molecules as a means of causing the ring component of a rotaxane or catenane to move from one position to another along an rod-like axle or larger ring component as a sophisticated means of sensing negatively charged species of biological, medical and environmental importance.
Through the attachment of nanoscale 'light bulbs' including luminescent metal 'filaments' inside an all carbon sphere-like football, to specific positions on the ring and axle components, the switching on or off of the light bulb is designed to occur when a target negatively charged species is recognised and causes ring components to slide or shuttle from one station position to another. Such materials can be thought of as "molecular machine-like sensors". Coating these materials on to conducting and optically transparent surfaces will produce devices that will change colour and/or emit light and undergo electrochemical perturbation in response to the addition of a specific negatively charged substrate. Fundamentally, the project will add considerable volume to our understanding of how complex molecular architectures, designed to exhibit dynamic motion, respond when confined to the sorts of surfaces that will, ultimately, underpin their application.

EP/P511377/1 EPSRC Institutional Sponsorship 2016 award, "A miniaturized atomic clock based on endohedral fullerenes", 1 August 2016 to 31 March 2017. Funding: £39,674 (Principal Investigator)

Project summary: Clocks are found inside billions of computer chips, worldwide. Atomic clocks enable accurate location calculation by timing, as used in GPS systems. At present, most atomic clocks are large and power-hungry; there is a clear need for a clock that could work inside a portable device. We are proposing a completely new approach to atomic timekeeping. We seek to build low-cost, solid-state miniature atomic clocks using nature's atom traps: endohedral fullerenes. Endohedral fullerenes are molecules in which a single spin-active atom or molecule is trapped inside a carbon cage. While protected by the cage from environmental disturbances, the resonances of the spin can be interrogated by radiofrequency magnetic fields. This is the basis for an entirely condensed-matter frequency standard. We lead the world in the synthesis and purification of endohedral fullerene systems such as N@C₆₀ where a single nitrogen atom is trapped inside a C₆₀ cage. Miniaturised atomic clocks would find a myriad of applications, from tracking objects and people to driverless cars. It would be of great technological and commercial benefit for Oxford to be the first to demonstrate a working prototype.

John Fell OUP Research Fund "Scaling up the production of endohedral fullerenes", 1 August 2013 to 31 March 2018. Funding: £67,500 (Principal Investigator)

Project summary: Fullerenes are cage-like molecules. The fullerene cages consisting of n carbon atoms are written C_n; when n = 60 the carbon atoms are arranged in a way similar to the vertices on a football. They are about 1 nm across which translates to the fullerenes being as many times smaller than a real football, as this football is smaller than the planet Earth! An atom of another element X can be incarcerated in this cage to produce a so-called endohedral (from Greek words literally meaning within the facets) fullerene, written X@C_n. Endohedral molecules can be manipulated, arranged in 1D chains, 2D lattices or even 3D crystals. Molecules such as N@C₆₀ have exceptionally long electron spin lifetimes. Endohedral fullerenes containing metal atoms in their interior (metallofullerenes) can have remarkable magnetic and optical properties offering practical applications in sensing, healthcare and quantum computing applications. Endohedral fullerenes were discovered about 30 years ago. However, the main limiting factor affecting their use in applications still remains. It is their rarity. They are currently available only in milligram quantities. It is this challenge that the proposed research aims to overcome. During the course of the research, manufacturing methods will be developed for increasing the production of endohedral fullerenes to the gram scale. Such quantities will allow fundamental studies of the physicochemical properties of endohedral fullerenes to be undertaken.

EP/K030108/1 EPSRC Fellowship "Manufacturing the Future; Endohedral fullerenes, small molecules, big challenges", 1 July 2013 to 30 June 2018. Funding: £1,509,283 (Principal Investigator)

Project summary: Fullerenes are cage-like molecules. The fullerene cages consisting of n carbon atoms are written C_n; when n = 60 the carbon atoms are arranged in a way similar to the vertices on a football. They are about 1 nm across which translates to the fullerenes being as many times smaller than a real football, as this football is smaller than the planet Earth! An atom of another element X can be incarcerated in this cage to produce a so-called endohedral (from Greek words literally meaning within the facets) fullerene, written X@C_n. Endohedral molecules have surface manoeuvrability and physical and electronic properties which are greatly enhanced as compared to free-standing atoms of X. They can be manipulated, arranged in 1D chains, 2D lattices or even 3D crystals. Endohedral fullerenes provide one with the ability to effectively manipulate a single atom or a small cluster of atoms that would be otherwise unattainable. Molecules such as N@C₆₀ have exceptionally long electron spin lifetimes. Endohedral fullerenes containing metal atoms in their interior (metallofullerenes) can have remarkable magnetic and optical properties. The main limiting factor affecting their use in applications still remains. It is their rarity. They are currently available only in milligram quantities. It is this challenge that the proposed research aims to overcome. During the course of the research, manufacturing methods will be developed for increasing the production of endohedral fullerenes to the gram scale. Such quantities are not only unprecedented, but they will also allow fundamental studies of the physical and chemical properties of endohedral fullerenes to be undertaken. Once this challenges are met, then the molecules can be controlled or even designed to have specific functionality for use in real-world applications.
The proposed programme of research will result in designer molecules for use in the electronics industry, the energy harvesting sector (photovoltaics) and medicine (free radical probes). In the longer-term hybrid materials will be developed in conjunction with other carbon allotropes (carbon nanotubes and graphene) for electronic devices that will be outperforming current classical technology. Endohedral fullerenes and their derivatives will be brought to the marketplace. The aim is that in the not-too-distant future, they will be found in devices used daily.

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