Biophysics

Joint seminar of the Institute of Physics, the Ruđer Bošković Institute and the Croatian Biophysical Society: Dr. Bruno Frka-Petešić

September 14, 2026.

Seminar at the Institute of Physics (joint seminar of IFS/IoPZg, IRB and HBD), Friday, September 18, 2026 at 11:00, 1st wing lecture hall and Zoom

Self-organization of cellulose nanocrystals into nanostructured photonic materials

Dr. Bruno Frka-Petešić

Yusuf Hamied Department of Chemistry, University of Cambridge, Cambridge, UK
International Institute for Sustainability with Knotted Chiral Meta Matter (WPI-SKCM2), Hiroshima University, Hiroshima 739-8526, Japan

The valorization of biomass into high-value materials requires efforts ranging from understanding the structural properties of the feedstock to controlling the physical and chemical processing steps and the principles of self-organization into final functional architectures. Cellulose, as the most abundant biopolymer on Earth, can be isolated from various sources and exhibits a native hierarchical structure that is impossible to artificially replicate. Under appropriate conditions, its processing allows the isolation of its crystalline compounds called cellulose nanocrystals (CNCs). These anisotropic and chiral colloidal nanorods represent a promising building block for the development of renewable and multifunctional nanomaterials. Remarkably, suspensions of CNCs can spontaneously form colloidal liquid crystals above a threshold volume fraction, exhibiting cholesteric order, while further evaporation of the solvent can produce nanostructured films that exhibit strong spectral reflectance in the visible range, resulting in vivid structural color.[1]

In this lecture, I aim to provide an introduction to the extraction and properties of cellulose nanocrystals, as well as their relevance for self-assembling optical materials. I will review recent advances in understanding the relationship between their morphology and liquid crystal behavior,[2] how to control their stacking to manipulate their optical properties,[3] and how to develop scalable strategies for optical materials.[4-5] If time permits, I will also say a few words about other systems of interest, such as polymeric liquid crystals, alignment under external fields, confinement effects, and buckling instabilities.

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Figure 1. Examples of colored films based on CNC (a, b) and their development into cellulose glitter (c, d).

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References [1] BFP, TG Parton, C. Honorato-Rios, A. Narkevicius, K. Ballu, Q. Shen, Z. Lu, Y. Ogawa, J. Haataja, B. Droguet, RM Parker, S. Vignolini, Chem. Rev., 123, 12595 (2023)

[2] TG Parton, RM Parker, GT van de Kerkhof, A. Narkevicius, JS Haataja, BFP, S. Vignolini, Nat. Commun., 13:2657, (2022)

[3] BFP, G. Kamita, G. Guidetti, S. Vignolini, Phys. Rev. Mater., 3, 045601 (2019)

[4] RM Parker, TH Zhao, BFP, S. Vignolini, Nat. Commun., 13:3378, (2022)

[5] BE Droguet, H.-L. Liang, BFP, RM Parker, MFL De Volder, JJ Baumberg, S. Vignolini, Nat. Mater., 21, 352, (2022)

Join the Zoom meeting:

https://us06web.zoom.us/j/5081440931

Meeting ID: 508 144 0931

Seminar hosts: Juraj Krsnik and Borna Radatović

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