Nanoscience Days 2026

Cellulose nanocrystal self-assembly into nanostructured photonic materials

Bruno Frka-Petesic 

B. Frka-Petesic1,2*
1 Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
2 International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), Hiroshima University, Hiroshima 739-8526, Japan; 
bf284@cam.ac.uk

Abstract. Cellulose nanocrystals (CNCs) are anisotropic and chiral colloidal nanorods that can be extracted from various cellulosic bio-sources and represent a promising building block for the development of renewable and multifunctional nanomaterials. Remarkably, CNCs can spontaneously form a colloidal liquid crystal above a threshold volume fraction, with a left-handed cholesteric order, and upon further solvent evaporation can produce nanostructured films that display strong spectral reflection in the visible range, resulting in vivid structural colour.[1-3] 
In this talk, I will discuss various aspects of the mechanisms responsible for such effect, and explore the various routes to control and utilise this phenomenon, from elucidating and controlling the chirality of CNCs at the individual level, to the implementation of strategies and constraints to drive their self-assembly into various nanostructured architectures, such as external fields, confinement or buckling instabilities.

References
[1] R. M. Parker, G. Guidetti, C. A. Williams, T. Zhao, A. Narkevicius, S. Vignolini, B. Frka-Petesic, Adv. Mater. 30, 1704477 (2018)
[2] B. Frka-Petesic, G. Kamita, G. Guidetti, S. Vignolini, Phys. Rev. Mater., 3, 045601 (2019)
[3] B. Frka-Petesic, T. G. Parton, C. Honorato-Rios, A. Narkevicius, K. Ballu, Q. Shen, Z. Lu, Y. Ogawa, J. Haataja, B. Droguet, R. M. Parker, S. Vignolini, Chem. Rev., 123, 12595 (2023)

Bio. Bruno is currently an Assistant Research Professor at the Department of Chemistry at the University of Cambridge, UK. He graduated theoretical soft matter physics in 2006 at Paris Diderot University, followed by a PhD in 2010 in experimental physics at UPMC (now Sorbonne University) in Paris. After short postdoctoral experiences in CERMAV-CNRS (Grenoble, France) and ENS (École Normale Supérieure, Paris, France), he joined in 2014 the Bio-Inspired Photonics group working with Silvia Vignolini on the self-assembly of organic nanocolloids for photonic materials. Since 2023, he is also an affiliated member of the International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2) based in Hiroshima University, and since 2026 a visitor scientist to the Max Planck Institute (MPIKG, Potsdam, Germany). Over the recent years, he became a specialist of cellulose nanocrystal self-assembly, and extended his research line to various aspects of the valorisation of naturally sources nanocolloids to design structured functional materials, from the identification and design of the key properties of the starting building blocks, to the control and development of suitable self-assembly routes.

Probing Dynamic Atomic Behaviour at Surfaces and Interfaces

Sarah Haigh

Sarah J. Haigh 1, Sam Sullivan Allsop1, Matthew Lindley1, Wendong Wang 2, Nick Clark1, Roman Gorbachev 2.
1. Department of Materials and National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK; 2. Department of Physics and Astronomy and National Graphene Institute, University of Manchester, Oxford Road, Manchester M13 9PL, UK;

Abstract. Scanning Transmission Electron Microscopy (STEM) enables direct imaging of local atomic structure and elemental composition to uncover structure-property relationships. For example, we have used this to uncover local nanostructure and thus support development of improved performance in ferroelectric films [1] and in electrocatalysts for water oxidation catalysts [2].  Yet (S)TEM imaging is typically performed in high vacuum environments which can cause artefacts relative to the sample in operando conditions. In situ (S)TEM using specialist holders or instruments enables imaging under more realistic environmental conditions. In this talk I will present some of our recent work illustrating how we have used STEM liquid cells to probe growth of tellurium nanowires, informing strategies for bulk electrodeposition at lower potential [3]. I will also report how we have applied in-situ gas cell STEM to investigate how the catalyst morphology evolves during activation heat treatment of cobalt oxides depending on the amount of doping with Mn promotor to optimise performance of Fischer Tropsch catalysts [4]. I will also report experiments using our graphene heterostructure liquid cells, which allow atomic resolution spatial resolution of solid catalysts surrounded by liquids including atomic scale dynamics at a solid-liquid interfaces [5]. We have developed a new polymer-free transfer technique to produce such graphene cells with minimal contamination and for a wide range of solvents [6]. Here we will report how this approach can be combined with an automated Noise2void machine learning image analysis pipeline [7] to allow new investigations of the dynamic behaviour of 10000-1000000 individual atomic sites at solid-liquid interfaces as a function of solvent environment [8].

References
[1] Y-Y-S, Cheng, et al (2026) Nature Materials 25, 73–79 https://www.nature.com/articles/s41563-025-02354-z 
[2] C. Liang, et al (2026) Nature Materials (in press, https://www.nature.com/articles/s41563-026-02514-9). 
[3] Y-C. Zou et al (2026) Matter (accepted, in press) 
[4] M. Lindley, et al (2024) ACS Catalysis, 14, 10648-10657 https://pubs.acs.org/doi/full/10.1021/acscatal.4c02721 
[5] N. Clark, et al (2022) Nature, 609, 942–947 https://www.nature.com/articles/s41586-022-05130-0
[6] W. Wang et al (2023) Nature Electronics, 6, 981–990  https://doi.org/10.1038/s41928-023-01075-y
[7] W. Thornley et al (2026) NPJ computational materials, 12, 86, https://www.nature.com/articles/s41524-025-01939-1 
[8] S. Sullivan-Allsopp et al (2026), Science, 392, 6793, 77-82 https://www.science.org/doi/10.1126/science.adw2469

Bio. Sarah Haigh is a Professor of Materials at the University of Manchester, UK whose research interests focus on advanced/in situ transmission electron microscopy (TEM) characterisation for improved understanding of nanomaterials behaviour. She completed undergraduate and doctorate degrees in Material Science at the University of Oxford (2004 and 2008) then worked as Consultant Application Specialist to JEOL UK before starting at Manchester in 2010. She is Vice Dean of Research and Innovation for the University of Manchester’s Faculty of Science and Engineering. She is also Director of the bp International Centre for Advanced Materials an academic-industrial collaboration set up with $100M investment from bp and focused on research towards net zero. She has been awarded ERC Starter and Consolidator grants and has published more than 200 peer reviewed journal papers and 5 book chapters. https://scholar.google.com/citations?user=rWFjXPEAAAAJ&hl=en

Supramolecular Control in Hybrid Perovskite Materials: 
from Photovoltaics to Neuromorphics for Sustainable Energy Technologies 

Jovana V. Milić* 

University of Turku, Finland; jovana.milic@utu.fi 

Abstract. Hybrid organic-inorganic framework materials have emerged as one of the most promising semiconductors in optoelectronics.[1] In particular, hybrid halide perovskite materials have demonstrated superior solar-to-electric energy conversion in photovoltaics. These are soft yet crystalline mixed ionic-electronic semiconductors with remarkable optoelectronic characteristics.[2,3] However, their limited stability in response to environmental factors, such as oxygen and moisture, as well as under operating conditions of voltage bias and light, hamper practical applications.[4] This is the result of ion migration that contributes to the reactivity at the interface, limiting stability under device operating conditions.[2] There has been an effort to overcome these shortcomings by developing tailored organic components that template hybrid perovskite frameworks and contribute to their stabilization through increased hydrophobicity and limited ion permeability, enhancing their performance in optoelectronics.[5,6] 
We demonstrate the capacity to rely on supramolecular engineering to develop a new generation of hybrid perovskite 
materials that respond to external stimuli and adapt to their operating conditions, such as by incorporating photochromic systems into ‘smart solar cells’ that can adapt to day-night cycles.[7] The dynamic control of the underlying ionic migration has set the basis for the utility of these materials in brain-inspired memory elements, as artificial synapses,[8] and self-powered memories for neuromorphic computing,[9] revealing new perspectives for hybrid framework materials, and more sustainable lead-free systems,[10]  in emerging technologies. 

Schematic of a hybrid perovskite material in neuromorphics 
 

References 
[1] S. Krause, J. V. Milić*, Commun. Chem. 2023, 6, 151. 
[2] J. Thiesbrummel, J. V. Milić, C. Deibel, E. C. Garnett, S. Tao, T. Kirchartz, A. Guerrero, P. Cameron, W. Tress, M. Saiful Islam, B. Ehrler, Nature Rev. Chem. 2026, in press. 
[3] L. A. Muscarella, J. V. Milić*, et al. Adv. Mater. 2022, 34, 202108720. 
[4] J. V. Milić*, J. Mat. Chem. C 2021, 9, 11428. 
[5] W. Luo, G. AlSabeh, J. V. Milić*, in Photochemistry (Eds.: S. Crespi, S. Protti), 2022, 50, 346–370. 
[6] G. AlSabeh, M. Grätzel, J. V. Milić*, et al. Angew. Chem. Int. Ed. 2025, e202417432. 
[7] W. Luo, J. V. Milić*, et al. Adv. Mater. 2025, 2420143. 
[8] M. M. Ganaie, G. Bravetti, S. Sahu, M. Kumar, J. V. Milić*, Mater. Adv. 2024, 5, 1880. 
[9] M. Loizos, K. Rogdakis, W. Luo, P. Zimmermann, A. Hinderhofer, J. Lukić, M. Tountas, F. Schreiber, J. V. Milić*, E. Kymakis*, Nanoscale Horiz. 2024, 9, 1146. 
[10] (a) M. Zhu et al., Chem. Soc. Rev. 2025, 54, 11719; (b) Adv. Energy Sust. Res. 2025, 2500028; (c) M. Ghasemi, et al. Adv. Energy Mater. 2025, 2502693; (d) L. A. Muscarella et al. Mater. Horiz. 2025, 12, 6124–6132; (e) M. M. Ganaie et al. Mater. Horiz. 2026, in press.

Bio. Jovana V. Milić has been an Associate Professor at the Department of Chemistry of the University of Turku in Finland since September 2024, supported by the Sustainable Materials and Manufacturing (SUSMAT) programme, Research Council of Finland, and European Research Council Starting Grant. She obtained her Dr.Sc. Degree in the Department of Chemistry and Applied Biosciences at ETH Zurich in Switzerland in 2017. She thereafter worked as a Scientist in the Laboratory of Photonics and Interfaces at EPFL, as a Swiss National Science Foundation PRIMA Fellow (since 2020), and as Assistant Professor (since 2021) at the Adolphe Merkle Institute of the University of Fribourg in Switzerland. Her research is centered around bioinspired stimuli-responsive (supra)molecular materials for energy conversion, with a particular interest in photovoltaics and neuromorphic computing for smart and sustainable technologies. In addition to research and cross-disciplinary international collaborations, she is involved at the interface of science, policy, and diplomacy toward sustainable development globally. For more information, please refer to www.jovanamilic.com.  
 

Kari Rissanen    
University of Jyväskylä