Sustainable and industrially scalable ultrasonic liquid phase exfoliation technologies for manufacturing 2D advanced functional materials (EcoUltra2D)
Lead Research Organisation:
Oxford Brookes University
Department Name: Faculty of Tech, Design and Environment
Abstract
Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.
People |
ORCID iD |
| Iakovos Tzanakis (Principal Investigator) |
Publications
Eskin D
(2023)
Sonoprocessing of materials (Special issue).
in Ultrasonics sonochemistry
Kaur A
(2024)
Dual frequency ultrasonic liquid phase exfoliation method for the production of few layer graphene in green solvents.
in Ultrasonics sonochemistry
Kaur A
(2022)
Temperature as a key parameter for graphene sono-exfoliation in water.
in Ultrasonics sonochemistry
Khavari M
(2023)
Cavitation-induced shock wave behaviour in different liquids.
in Ultrasonics sonochemistry
Khavari M
(2021)
Scale up design study on process vessel dimensions for ultrasonic processing of water and liquid aluminium.
in Ultrasonics sonochemistry
Khavari M
(2021)
Characterization of shock waves in power ultrasound
in Journal of Fluid Mechanics
Morton J
(2022)
An Eco-Friendly Solution for Liquid Phase Exfoliation of Graphite Under Optimised Ultrasonication Conditions
in SSRN Electronic Journal
Morton J
(2023)
Dual frequency ultrasonic cavitation in various liquids: High-speed imaging and acoustic pressure measurements
in Physics of Fluids
Morton J
(2021)
New insights into sono-exfoliation mechanisms of graphite: In situ high-speed imaging studies and acoustic measurements
in Materials Today
| Description | The focus of this project is on finding a technological way of producing graphene and few-layer graphene using ecological solutions. Therefore, we use pure water and ultrasonic vibrations for exfoliation and dispersion of graphene flakes. So far we have produced graphene of quality and size comparable with the best published results of other research groups worldwide, while having used only water and rather short treatment times. The optimisation of process parameters is the key of success. The mechanisms of ultrasonic exfoliation are under scrutiny using the most advanced characterisation techniques and unique in-situ observations. The principal role of shockwaves emitted upon collapse of cavitation bubbles has been established. It is demonstrated that the use of two ultrasonic sources with low (20 kHz) and high (1 MHz) frequencies facilitates the exfoliation and improves the quality of graphene flakes. Unique acoustic measurements have been made to explain the mechanism of dual frequency exfoliation. In-situ studies using optical and X-ray high-speed imaging revealed a number of previously unknown mechanisms of cavitation-induced exfoliation, which are also supported by numerical modelling and acoustic measurements. An important role of shock-waved emitted upon cavitation has been revealed and quantified. A new acoustic signature of exfoliation has been identified (MHz-frequency peak) that can be potentially used for monitoring the exfoliation accomplishment. A number of high-ranking papers have been published and more are in preparation. The results have been reported at a number of important international conferences. Current efforts are focused on further improvement of the exfoliation yield (>10%) and quality (less than 8 layers, size large than 1 µm) by a combination of green and eco-friendly solvents and surfactants with promising results starting to emerge. Also the first steps towards testing and functionalisation of graphene flakes have started by Greenwich university towards fabrication of eco-graphene based electrodes for fuel cell applications. Unfortunately the planned contribution of Oxford/Greenwich partners has not been realised to a full measure. Multiple issues in communication, access to the equipment, references to the lack of time and other difficulties prevented the consortium from using Oxford experiments and facilities to the planned extent. As a result, only one paper has originated based on the results of this team. Brunel and Oxford Brookes Universities had, therefore, extra work carried out. Despite receiving excellent reviews, a follow-up grant proposal was not supported by EPSRC, which was a great disappointment. However, the results sparked the interest of many institutes worldwide, and eventually, collaboration with Sabanci University in Turkey led to a successful grant from the Royal Society in 2023 through the Isaac Newton International Fellowships award. This grant is aimed at scaling up our eco-friendly approach using a combination of hydrodynamic and acoustic cavitation. |
| Exploitation Route | A number of high-impact journal publications are published and in preparation. The results have been reported at a number of international conferences. |
| Sectors | Chemicals Energy Environment Manufacturing including Industrial Biotechology Pharmaceuticals and Medical Biotechnology |
| Description | It is shown that a combination of low- and high frequency ultrasonic sources gives a synergetic effect in the efficiency of liquid-phase exfoliation of graphite. Acoustic measurements demonstrate the increase of acoustic pressure due to the use of two different-frequency sources. This allows us to use pure water free of polluting and harmful additions and considerably shorter processing times than has been reported before. A number of green/eco-friendly surfactants are used to increase the yield and quality of the 2D flakes by improving the separation and stability of produced mixtures. Advanced in situ observations and measurements provide insights into the previously uncharted mechanisms of mechanical exfoliation of graphite by cavitation bubbles of difference sizes as well as by acoustic flows. The optimization of process parameters and control of cavitation dynamics, along with the upscaling of the process, have been successful through the implementation of a continuous recirculating-flow reactor. The main outcome is the development of a technology for eco-friendly production of graphene for medical (drug delivery and diagnostics) and environmental (water purification) applications, which is currently being tested with FORTH (Greece) and the Faculty of Health Sciences, Biomedical Science (BMS), at Oxford Brookes University. Additionally, collaborations include solar cell fabrication with HMU (Greece) and carbon fiber production in partnership with Imperial College. A highly rated research proposal (EcoCavActor; grades 6, 5, 5) was submitted to EPSRC in 2021 with the aim of upscaling the results of this research. Unfortunately, despite EPSRC's keen interest in funding the project, it was held for four consecutive engineering prioritization meetings due to budget constraints. Regrettably, EPSRC was unable to allocate sufficient budget to support this proposal. Alternative routes were pursued in this direction. Subsequently, Building on the EcoUltra2D project outcomes, which laid the foundation, two research proposals were funded: one by the Royal Society (International Newton Fund Award; NIF\R1\221238), where a new approach is proposed for eco-friendly graphene exfoliation and other 2D materials production at large scale utilising hybrid acoustic and hydrodynamic cavitation technologies; and another one by the British Council ISPF (1203770538) to design a bespoke reactor from the knowlenge gained from 2D nanomaterials exfoliation research for tackling forever chemicals and specifically PFAS. The latter has received signigicant global recognition, with covergave in major outlets including ITV and BBC news as well as a dedicated episode on BBC click (popular TV science show) |
| First Year Of Impact | 2021 |
| Sector | Chemicals,Energy,Environment,Manufacturing, including Industrial Biotechology,Pharmaceuticals and Medical Biotechnology |
| Impact Types | Societal Economic |
| Description | AquaCav: Clean Water using the Power of Cavitation Bubbles |
| Amount | £100,000 (GBP) |
| Funding ID | 1203770538 |
| Organisation | British Council |
| Sector | Charity/Non Profit |
| Country | United Kingdom |
| Start | 07/2024 |
| End | 08/2026 |
| Description | Large Scale Exfoliation of 2D nanomaterials using an Environmentally Friendly Hybrid Cavitation Reactor |
| Amount | £145,000 (GBP) |
| Funding ID | NIF\R1\221238 |
| Organisation | The Royal Society |
| Sector | Charity/Non Profit |
| Country | United Kingdom |
| Start | 03/2023 |
| End | 03/2026 |
| Title | Signal Processing Matlab code |
| Description | Develop an in-house Matlab code to process acoustic signals from a range of calibrated to NPL sensors. This was proven instrumental for data processing and analysis, numerical model optimazation and succesful completion of a number of journal papers. |
| Type Of Material | Improvements to research infrastructure |
| Year Produced | 2021 |
| Provided To Others? | Yes |
| Impact | Without this tool we wouldn't be able to process the collected data and thus generate meaningful results. Also this tool is free to download from the http://cav-it.co.uk/ (website under development) and use for research or teaching purposes. |
| Description | Calibration, data acquisition, testing of hydrophones for detection of shock waves in collaboration with Precision Acoustics Ltd |
| Organisation | Precision Acoustics Ltd |
| Country | United Kingdom |
| Sector | Private |
| PI Contribution | We tested the calibrated hydrophones under cavitation conditions, captured and analysed shock waves |
| Collaborator Contribution | PA provided assistance in calibration of a range of fiber optics to needle hydrophones as well as solving issues with data acquisition. This enhances their expertise in measuring acoustic signals during the propagation of shock waves by bubbles implosion. . |
| Impact | We used an advanced strategy/approach and combined efforts with PA to capture and analyse bands of shock waves from implosion of cavitation bubbles. We deployed advanced audio-visual methods (high speed camera up to 1 million frames per second and calibrated hydrophone sensors) that also included unique synchronisation techniques of acoustic emissions with video recordings. PA's contribution was essential to this exercise as they provide guidance on data analysis and insightful thoughts on the development of a manuscript that was eventually published in the Journal of Fluid Mechanics (JFM) in 2021 and is gaining traction. This in-depth understanding of shock waves allowed us to publish a series of other papers in the following journals: Ultrasonics Sonochemistry, Carbon, Tribology International, Physics of Fluids, JOM - Minerals, Metals and Materials Society. Furthermore, the calibrated sensors enabled us to monitor pressure fields within the novel dual-frequency reactor developed for this project. This real-time monitoring facilitated the optimization of the reactor and control of cavitation dynamics, ultimately leading to advancements in the exfoliation process of 2D nanomaterials. On-going extends into atomization where synchronised acoustic measurements and high speed video recordings allowed us to resolve and capture shock wave events occured during atomization that led to two more publications (Ultrasonics Sonochemistry and Additive Manufacturing). The results contribute to a deeper understanding of metallic powder development in collaboration with our industrial partner, Amzamet. |
| Start Year | 2021 |
| Description | Collaboration with FORTH (Greece) regarding cytotoxicity assessment of bio-friendly Graphene flakes for nanocarrier applications via NFFA call (Horizon, ID:184) |
| Organisation | Foundation for Research and Technology Hellas (FORTH) |
| Country | Greece |
| Sector | Public |
| PI Contribution | Ultrasonic liquid phase exfoliation of graphite in Phosphate Buffer Saline (PBS) yielded graphene flakes, which were assessed for cytotoxicity on mouse fibroblasts NIH-3T3 cells in FORTH and in human cells at OBU's Faculty of Health Sciences, Biomedical Science (BMS). The study aimed to evaluate the potential of bio-friendly graphene nanocarriers for targeted drug delivery in oncology, showing promising results with low cytotoxicity in fibroblast and human cells RPE-1 cells and higher efficacy in He-La cancer cells. |
| Collaborator Contribution | FORTH: Tested graphene with fibroblasts using standard protocols and procedures including nonlinear microscopy, live cell imaging, scanning electron microscopy and cell culture facilities BMS: Tested graphene with human and cancer cells using standard protocols and procedures involving calorimetric MTT assays |
| Impact | A manuscript on aqueous graphene's viability and morphology is due for submission The Post-doc working in this project has also submitted in 2023 a Dorothy Hodgkin (DH-2023/24) eight-year grant application to The Royal Society entitled "Eco-Graphene, a promising bio-compatible nanocarrier from nanotechnology to nano-oncology" to investigate the potential of bio-friendly grapehene nanocarriers in stimuli-responsive targeted drug delivery A follow up NFFA Horizon proposal (ID: 521) has been submitted and accepted with further tests scheduled for summer 2024 in the FORTH facilities An EPSRC proposal based on nanoengineering and functionalization of grapehne nanocarriers for gene transport and vaccine development between Brunel and Oxford Brookes supported by FORTH, involving biomedical departments from both universities, is in the early stages |
| Start Year | 2022 |
| Description | Collaboration with Imperial College (Prof. Shaffer and Dr. Brandt-Talbot) for the production of carbon fibres from lignin/graphene dopes |
| Organisation | Imperial College London |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | We developed lignin/graphene dopes (12 wt. % lignin+0.5 wt. % graphene) and graphene dispersions in appropriate water/ethanol/ionic liquid ratios (0.5 wt.%) with our novel ultrasonic technique developed in the EcoUltra2D project. |
| Collaborator Contribution | Studies on solubility, rheology and wet-spinning of obtained dopes were carried out at Imperial College London. |
| Impact | We have obtained carbon fibres from lignin/graphene dopes; the obtained fibres were fragile with coagulation of small fibres (of length 1-2 cm); next step is tailoring of the dope composition with improved graphene concentration to produce robust fibres |
| Start Year | 2023 |
| Description | In-situ study of exfoliation |
| Organisation | University of Glasgow |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | We provided materials, manpower and analysis for the unique experiments on in-situ observation of graphite exfoliation by a single-bubble cavitation. |
| Collaborator Contribution | Dr P. Prentice provided unique facilities and expertise for conducting these experiments. |
| Impact | A number of journal papers are expected as a result of this collaboration. |
| Start Year | 2019 |
| Description | Ultra-high speed camera observations |
| Organisation | University of Glasgow |
| Country | United Kingdom |
| Sector | Academic/University |
| PI Contribution | We have experimentally identify for the first time the prime responsible mechanism (shock waves from collapsing bubbles) for the fragmentation of metallic crystals in a sonicated environment as well as the importance of shock waves on atomization of liquid droplets and exfoliation of 2D nanomaterials |
| Collaborator Contribution | Allowed us to use their state of the art laser-induced bubble facility providing knowledge and expertise |
| Impact | Collaboration with Glasgow University led to the publications of numerous journal papers in prestigious journals like Journals of Fluid Mechanics, Additive Manufacturing and Ultrasonics Sonochemistry while joint conference papers have been included in the relevant proceedings. This is a fruitful collaboration with a decent number of outcomes that further advanced the existing knowledge on the field of shock waves as well as elucidate the mechanisms of bubble dynamics and their interaction with solid and liquid phases. |
| Start Year | 2019 |
| Description | ESS-JSS-AOSS 1st JOINT SONOCHEMISTRY CONFERENCE (ONLINE) |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Two presentations at this major Sonochemistry event |
| Year(s) Of Engagement Activity | 2021 |
| Description | Graphene 2021 |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Industry/Business |
| Results and Impact | Two presentations at the major event on graphene science and technology: Graphene 2021 (October 26-29, 2021 Grenoble (France)) |
| Year(s) Of Engagement Activity | 2021 |
| Description | Invited talk at the 2D symposium within TMS 2023 |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | Invited talk at the Symposium on 2D Materials (TMS Annual Meeting, San Diego, March 2023) |
| Year(s) Of Engagement Activity | 2022 |
| Description | Participation and talk in the 17th Meeting of the European Society of Sonochemistry |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | One presentation in this major event, which sparked questions and discussions on the fundamentals of bubble dynamics and cavitation processes due to new insights/knowledge that was discovered in this project |
| Year(s) Of Engagement Activity | 2022 |
| Description | Participation in CAV 2021 Symposium |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | One presentation on the 11th International Symposium on Cavitation 2021 (CAV2021), Virtual Conference from 10 to 13 May 2021 in Korea |
| Year(s) Of Engagement Activity | 2021 |
| Description | Science Bazaar at Oxford Brookes University |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | National |
| Primary Audience | Schools |
| Results and Impact | We has showcased our research activities to a diverse audience, including schoolchildren, families, young scientists, and the general public over the Science Bazaar annual event, attracting more than 7,000 visitors from all backgrounds and offers a free, hands-on exploration of science in its broadest sense. We demonstrated our work on materials, including nanomaterials and alloys, highlighting their potential to shape the future. |
| Year(s) Of Engagement Activity | 2024,2025 |
| URL | https://www.brookes.ac.uk/science-bazaar |
| Description | Talk at CAV2021 |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Industry/Business |
| Results and Impact | A talk at the 11th International Symposium on Cavitation, May 10-13, 2021, Daejon, Korea |
| Year(s) Of Engagement Activity | 2021 |
| URL | http://cav2021.org/ |
| Description | Talk at TMS2022 2D materials |
| Form Of Engagement Activity | A talk or presentation |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Industry/Business |
| Results and Impact | A talk at the symposium 2D Materials - Preparation, Properties & Applications within the TMS 2022 Annual Meeting in Anaheim, USA |
| Year(s) Of Engagement Activity | 2022 |
| Description | World Conference on Carbon |
| Form Of Engagement Activity | Participation in an activity, workshop or similar |
| Part Of Official Scheme? | No |
| Geographic Reach | International |
| Primary Audience | Professional Practitioners |
| Results and Impact | We had 2 presentations regarding the exfoliation of graphene using our novel reactor in green solvents that sparked fruitful discussions and led to the collaboration with Imperial College and Prof. Milo Shaffer |
| Year(s) Of Engagement Activity | 2022 |
| URL | https://www.rsc.org/events/detail/73030/carbon-2022 |