PhD project: Surface Modification of Hafnium Oxide via Sol-Gel Synthesis for the Improvement of Conductivity and Mechanical Stability of Anion Exchange Membranes for Fuel Cells

Curriculum: I have started my academic studies in 2015 at the University of Palermo (Italy), obtaining a Bachelor’s degree in Energy engineering in 2018.
Subsequently, I started my Master degree in 2018 in Energy engineering at the University of Bolzano and Trento and I graduated in January 2021.
My master thesis work dealt with the preparation of polyamine membranes for anion-exchange membrane fuel cells applications, and it was realized under the supervision of Dr. Narges Ataollahi and Professor Paolo Scardi.
I have been assigned as research assistant since March 2021 in the department of civil, environmental, and mechanical engineering, at University of Trento. The main topic of research was the study of innovative anion exchange membranes based on functionalized polyketone and their application on alkaline fuel cells. In November 2021, I have obtained the position as PhD student at the Energy and Materials Lab at the University of Trento, under the supervision of Prof. Narges Ataollahi, Prof. Paolo Scardi, and Prof. Luca Deseri.
The research work includes the synthesis of functionalized hafnia nanoparticles and the synthesis of polyketone based anion exchange membranes improved with the addition of these nanoparticles, as well as their characterization and multiscale modelling, eventually using them in working alkaline fuel cells.
The experimental work runs in parallel with a multiscale computational simulation, aiming at foreseeing the chemical, physical and mechanical properties of the membranes, to eventually optimize the synthetized ones.

LinkedIn: https://www.linkedin.com/in/eleonora-tomasino-858929155/

Google Scholar: https://scholar.google.com/citations?user=S3WZAc4AAAAJ&hl=it
 

1^st year

Research activities

During the first year of my PhD, the research activities including both experimental work and computer simulations are performed in parallel. Anion exchange membranes based on polyamine (PA) have been employed as solid electrolytes in alkaline fuel cells. PA was obtained from terpolymer polyketone, subjected to a Paal-Knorr reaction to introduce amine groups and subsequently to an ionization and OH exchange processes to convert the groups into trimethylammonium cationic groups, responsible for the water uptake and the conductivity of the anionic species (OH-). The detailed synthesis procedure of this membrane has already been investigated and an article has been published (https://doi.org/10.3390/en15051953). The overall properties of the membranes are improved by the addition of functionalized nanoparticles (modified silica). Hence, a new research has been started using Hafnia (HfO2) nanoparticles modified with 3-silane, which are expected to have a beneficial effect on thermomechanical properties, water uptake, and ionic conductivity. The first year was mainly devoted to the computational modelling of the polymeric membranes. Initially, ab-initio density functional theory (DFT) was used to investigate the hydrophilic/hydrophobic behaviour of the PA, the interaction with OH- and the role in ionic conductivity. A paper on this research work has been published in September 2022 (https://doi.org/10.1021/acs.jpcb.2c04115). Secondly, larger scale simulations are performed on hydrated membranes, using molecular dynamics (MD) simulation to gain a deeper knowledge of the morphology of the membranes at the molecular level. Different membranes are simulated, varying the degree of amination and the water content λ. We can obtain details on the formation of interconnected water channels, essential for ionic conductivity, the diffusion coefficients of both water and OH-, the activation energies and the conductivity, as well as some mechanical properties. All these parameters can be validated with the experimental data. In parallel to the computational work, laboratory activity has been conducted, including the synthesis of polyamine with different degrees of amination, the production of the membranes and some mechanical tests, to validate the simulation results. Moreover, hafnia nanoparticles have been synthesized via sol-gel method and have been functionalized with 3-silane, to introduce amine side chains to the surface of the oxide. The modified hafnia has been characterized with FTIR, SEM, XRD, TGA, Raman Spectroscopy, DSC, DLS and EDX.

Research output

Published papers:
1) E. Tomasino, B. Mukherjee, N. Ataollahi, P. Scardi, Water Uptake in an Anion Exchange Membrane Based on Polyamine: A First-Principles Study, J. Phys. Chem. B, 2022, 15, 1953. https://doi.org/10.1021/acs.jpcb.2c04115
2) N. Ataollahi, E. Tomasino, O. Cotini, R. Di Maggio, Enhanced OH- Conductivity for Fuel Cells with Anion Exchange Membranes, Based on Modified Terpolymer Polyketone and Surface Functionalized Silica, Energies, 2022. https://doi.org/10.3390/en15051953
 

Teaching Activities
1)High-Performance Computing (HPC) summer school 2022, 29 Aug-2 Sep 2022, Oral presentation
2)Supervision of master student for thesis work

2^nd year

Research activities

During the second year of my PhD, experimental work and computer simulations were concurrently conducted. The main laboratory activity was focused on the synthesis and characterization of functionalized TiO2 nanoparticles with different compounds (2-silane and 3-silane). The modification of nanoparticles was carried out via sol-gel reactions, resulting in grafting of amine groups onto titania surface. The synthesis of these NPs was intended to produce functionalized nanofillers to be added to anion exchange membranes (AEMs) for fuel cell applications. The aim is to improve the properties of AEMs, including water uptake, conductivity, and mechanical stability. The NPs were successfully added to polyamine-based AEMs and some tests were made on new membranes synthesized from PET bottles. Further investigations will be conducted and a draft of paper is under development. The computational modelling of hydrated PA membranes was conducted via Molecular Dynamics (MD) simulations. By means of these simulations it was possible to analyze the effects of degree of amination, water content and temperature on different properties (morphology, conductivity, and mechanical properties). In addition to classical MD, a reactive force field has been used to investigate the role of Grotthuss mechanism on ions diffusivity. A paper is under review by the journal: ACS The Journal of Physical Chemistry C. Moreover, density functional theory (DFT) simulations were carried out to study both functionalized nanoparticles and PET-based AEMs. Particularly, computational chemistry was used in the second case to validate the predicted structure synthesized in the laboratory (via FTIR and NMR simulations) and to investigate the degradation mechanisms in alkaline conditions (cvia a Transition State Analysis). An article has been published in ACS Appl. Polym. Mater. (https://doi.org/10.1021/acsapm.3c01391). Finally, by the end of October I will start a new project on the synthesis, characterization, and computational modelling of anion exchange membrane water electrolysers (AEMWE) based on recycled PET for hydrogen production.

Research output

Published paper:
1) V. D. Neelalochana, E. Tomasino, R. Di Maggio, O. Cotini, P. Scardi, S. Mammi, N. Ataollahi, Anion Exchange Membranes Based on Chemical Modification of Recycled PET Bottles, ACS Appl. Polym. Mater. 2023, 5, 9, 7548-7561 (https://doi.org/10.1021/acsapm.3c01391)
Paper under review:
2) E. Tomasino, B. Mukherjee, V. D. Neelalochana, P. Scardi, N. Ataollahi, Computational Modelling of Hydrated Polyamine-based Anion Exchange Membranes via Molecular Dynamics Simulation, 2023

Teaching Activities

1)Supervision of master student for thesis work
2)Oral Presentation for the PhD course: Molecular Dynamics: a primer with elements of statistical mechanics
 

3^rd year

Research activities

During the third year of my PhD, I continued both experimental research and computational chemistry analyses focused on optimizing polyamine (PA)-based anion exchange membranes (AEMs). The previously synthesized functionalized TiO2 nanoparticles were successfully incorporated into both PA and PET-based AEMs. These nanocomposite membranes were thoroughly characterized, demonstrating improved ionic conductivity, mechanical, thermal, and chemical stability. Regarding PET-based nanocomposite membranes, our results were published in Electrochimica Acta journal (https://doi.org/10.1016/j.electacta.2024.145170). A manuscript detailing the work on nanocomposite PA membranes is currently under preparation. Additionally, new polymers were synthesized starting from PA, by grafting heterocyclic quaternary ammonium groups (pyrrolidinium and piperidinium) via long side chains containing hydroxyl groups. This work constitutes a preliminary study, requiring further investigation. Membranes showing higher ionic conductivity were effectively obtained from these new materials, however they showed inadequate structural and chemical stability. To complement this work, a multiscale computational chemistry analysis, using both density functional theory (DFT) and molecular dynamics (MD) simulations, has been conducted. This approach provided deeper insights into both existing and newly proposed materials, with the aim of identifying PA-based polymers with optimized properties for enhanced AEMs.

Research output

Published paper:
1) V. D. Neelalochana, E. Tomasino, M. A. Malagutti, I. Mancini, A. Chiappini, S. Shadakshari, M. W. Terban, B. Hinrichsen, P. Scardi, N. Ataollahi, Impact of functionalized titanium oxide on anion exchange membranes derived from chemically modified PET bottles, Electrochemical Acta 2024, 507, 145-170 (https://doi.org/10.1016/j.electacta.2024.145170)
2) E. Tomasino, B. Mukherjee, V. D. Neelalochana, P. Scardi, N. Ataollahi, Computational Modeling of Hydrated Polyamine-Based Anion Exchange Membranes via Molecular Dynamics Simulation, J. Phys. Chem. C 2024, 128, 623-634 (https://doi.org/10.1021/acs.jpcc.3c07118)
Manuscripts under writing:
1) Experimental and Computational strategies for the Enhancement of Anion Exchange Membranes for Electrochemical applications: a Review
2) Effects of Functionalized TiO2 Nanoparticles on Nanocomposite Polyamine-based Anion Exchange Membranes

Teaching Activities

I assisted in teaching the laboratory section of the master's course Inquinanti emergenti e strategie di risanamento, conducting activities on PET recycling strategies