Guido Panzarasa

Last Name

Panzarasa

First Name

Guido

ORCID

0000-0003-1044-0491

Organisational unit

03917 - Burgert, Ingo / Burgert, Ingo

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Publications1 - 10 of 48

Universality of breath figures on two-dimensional surfaces: An experimental study
Stricker, Laura; Grillo, Fabio; Marquez, E.A.; et al. (2022)
Physical Review Research
Droplet condensation on surfaces produces patterns, called breath figures. Their evolution into self-similar structures is a classical example of self-organization. It is described by a scaling theory with scaling functions whose universality has recently been challenged by numerical work. Here, we provide thorough experimental testing, where we inspect substrates with vastly different chemical properties, stiffness, and condensation rates. We critically survey the size distributions and the related time-asymptotic scaling of droplet number and surface coverage. In the time-asymptotic regime, they admit a data collapse: the data for all substrates and condensation rates lie on universal scaling functions.
Hybrid Adsorbent Materials Obtained by the Combination of Poly(ethylene-alt-maleic anhydride) with Lignin and Lignosulfonate
Panzarasa, Guido; Osypova, Alina; Ribera, Javier; et al. (2018)
Journal of Polymers and the Environment
Lignin is one of the most available biomass products, but its potential for the development of functional materials has yet to be unleashed. Here, the modification of lignin and lignosulfonate with poly(ethylene-alt-maleic anhydride) [P(E-alt-MA)], a functional polymer of wide industrial use, is accomplished by means of a simple esterification reaction. As a result, hybrid adsorbent materials for water purification can be obtained, which were thoroughly characterized. The combination of P(E-alt-MA) with lignin increased hydrophilicity of the latter, making it dispersible in aqueous environments, while with lignosulfonate it gave rise to a water-insoluble, thus easily recoverable, product. The adsorption properties of the resulting products have been tested against a model water pollutant (methylene blue), demonstrating remarkable adsorption speed (in the order of minutes), adsorption efficiency and stability over a wide range of pH (2–12). Moreover, after the incorporation of magnetite nanoparticles by in situ synthesis, adsorbent materials able to be magnetically recovered were developed.
The horseradish smile: Demonstrating characteristic reactions of peroxidase in a visually appealing way
Panzarasa, Guido (2020)
Biochemistry and Molecular Biology Education
Easy and visually appealing demonstrations are precious tools for introducing students to the study of enzymes. However, they most often involve purified enzymes and dedicated techniques. Here, we propose a set of demonstrations, which require only fresh horseradish root and consumer chemicals, to help support biochemistry and enzymology courses from high school to the undergraduate level. Horseradish root is a naturally rich source of horseradish peroxidase, an enzyme with many relevant practical applications. Slices of horseradish root are used to demonstrate the characteristic reaction of horseradish peroxidase with hydrogen peroxide, the selective inhibition of this enzyme by dilute hydrochloric acid, its chromogenic reaction with N,N′‐diethyl‐p‐phenylenediamine, and its ability to trigger the chemiluminescent reaction of luminol. © 2019 International Union of Biochemistry and Molecular Biology, 48(1):38–43, 2020.
Time-domain Tollens reaction: synthesising silver nanoparticles with the formaldehyde clock
Kürsteiner, Ronny; Ritter, Maximilian; Sologubenko, Alla; et al. (2023)
Nanoscale Advances
The addition of silver(i) ions to the methylene glycol-sulphite (MGS) clock reaction results in the sudden formation of metallic silver nanoparticles. Stable suspensions are obtained in the presence of poly(vinylpyrrolidone). The time delay before the appearance of the particles, as well as their size, decreases with the initial methylene glycol concentration while their monodispersity increases.
Just Add Luminol to Turn the Spotlight on Radziszewski Amidation
Panzarasa, Guido (2018)
ACS Omega
Radziszewski amidation, namely the peroxide-mediated conversion of nitriles into amides, is a chemiluminescent reaction involving singlet oxygen. Its increasing relevance in green chemistry and analytical chemistry makes it an important subject to be discussed in advanced chemistry courses. To turn the attention of lecturers, teachers, and students toward this reaction, the history of its discovery as well as its practical applications is discussed. Moreover, a simple and effective experiment to demonstrate the chemiluminescent properties of Radziszewski amidation is provided.
Stable and transient self-propagating supramolecular gelation
Riedel, Solenn; Panzarasa, Guido (2021)
Molecular Systems Design & Engineering
The ability to program sol-gel transition in time is key for living organisms to maintain their vital functions and to grow complex materials. Replicating this behavior with synthetic chemical networks is challenging, but highly rewarding for the design of intelligent biomimetic materials. Thanks to a combination of autocatalysis and supramolecular complexation, the iodate-hydroxymethanesulfinate-poly(vinyl alcohol) system features the emergence of self-propagating gelation fronts, stable or transient depending on the fine-tuning of the system.
Sustainable wood electronics by iron-catalyzed laser-induced graphitization for large-scale applications
Dreimol, Christopher; Guo, Huizhang; Ritter, Maximilian; et al. (2022)
Nature Communications
Ecologically friendly wood electronics will help alleviating the shortcomings of state-of-art cellulose-based “green electronics”. Here we introduce iron-catalyzed laser-induced graphitization (IC-LIG) as an innovative approach for engraving large-scale electrically conductive structures on wood with very high quality and efficiency, overcoming the limitations of conventional LIG including high ablation, thermal damages, need for multiple lasing steps, use of fire retardants and inert atmospheres. An aqueous bio-based coating, inspired by historical iron-gall ink, protects wood from laser ablation and thermal damage while promoting efficient graphitization and smoothening substrate irregularities. Large-scale (100 cm2), highly conductive (≥2500 S m−1) and homogeneous surface areas are engraved single-step in ambient atmosphere with a conventional CO2 laser, even on very thin (∼450 µm) wood veneers. We demonstrate the validity of our approach by turning wood into highly durable strain sensors, flexible electrodes, capacitive touch panels and an electroluminescent LIG-based device.
Reconstructing Poplar Wood into a High-Performance Fiber-Reinforced Biocomposite
Movahedi-Rad, A. Vahid; Ritter, Maximilian; Kindler, Robert Oswin; et al. (2024)
ACS Sustainable Chemistry & Engineering
Green high-performance composite materials are in great demand thanks to the increased environmental awareness. Wood is a natural fiber-reinforced polymer composite, but its properties can hardly compete with those of artificial, much less sustainable, ones. In Central Europe, climate change-induced environmental changes will force the industrial adoption of fast-growing, drought-resistant wood species (such as poplar) with inferior mechanical properties compared to more commonly used ones (such as spruce). In response to these challenges, we describe the fabrication of a novel fully biobased high-performance composite obtained by reconstructing poplar wood. Our process is based on a combination of structure-retaining delignification, relignification, and densification, resulting in a product with superior mechanical properties and water stability. Our "reconstructed poplar" is a green composite suitable for engineering applications and an example of undervalorized wood species upcycling.
Scalable and sustainable wood for efficient mechanical energy conversion in buildings via triboelectric effects
Sun, Jianguo; Schütz, Urs; Tu, Kunkun; et al. (2022)
Nano Energy
Triboelectric nanogenerators (TENG) have great potential to help enhancing the energy efficiency of buildings, and thus to contribute significantly to the reduction of global greenhouse gas emissions. However, there are major barriers against the adoption of such emerging energy technologies. Meeting the need for sustainable large-scale fabrication of high-performance products remains a critical challenge towards real-world TENGs’ building applications. To mitigate this challenge, we enhance the poor polarizability of native wood by a scalable plasma treatment, a facile approach which to the greatest degree preserves wood's warm colors, mechanical robustness while efficiently enhancing the triboelectric output. We demonstrate the enhancement of electric output by assembling wood triboelectric nanogenerators (W-TENGs) in both contact-separation and single-electrode operation modes. We show that when two radial-cut wood samples (L × R × T: 100 × 80 × 1 mm3), one treated with an O2 plasma and the other with a C4F8 + O2 plasma, are subjected to periodic contact and separation with an applied pressure as low as 0.0225 MPa, a maximum voltage of 227 V and a current of 4.8 µA are produced. Eventually, we showcase the real-world applicability of our approach with two prototypes of triboelectric wood floors, opening up new technological pathways towards a ‘net-zero emissions’ future.
Iron-Catalyzed Laser-Induced Graphitization Enabling Current Collector-Free Electrodes With Spatially Tunable Iron/Iron Oxide Phases
Dreimol, Christopher; Edberg, Jesper; Kürsteiner, Ronny; et al. (2025)
Advanced Materials
Iron-catalyzed laser-induced graphitization (IC-LIG) represents an eco-efficient alternative to traditional carbon electrode manufacturing. Combining a bio-based tannic acid-iron precursor ink with CO₂ laser treatment results in sheet resistance of 23.59 ± 1.2 Ω square⁻¹ on renewable substrates. Varying the tannic-acid-to-iron ratio (TA:Fe), the rheology of the precursor ink can be tuned, enabling versatile application techniques, including spray coating, screen printing, and direct-ink-writing (DIW). Subsequent laser-treatment enables the formation of functional IC-LIG electrodes for all application methods, while even thick DIW-printed layers (260 μm) result in complex, conductive electrode patterns. Laser post-treatment expands design possibilities by locally tuning iron phases, such as converting γ-iron to magnetite. The unidirectional laser-treatment results in a layered arrangement, forming a multilayer electrode with a highly graphitized top layer serving as a current collector substitute, and an underlying composite of iron-rich nanoparticles embedded in a porous graphitic foam, acting as a hybrid electrode. Electrochemical analysis reveals double-layer capacitor behavior at low TA:Fe ratios, while higher ratios demonstrate increased redox activity and pseudo-capacitive characteristics. Achieving stable capacities of 15 mF cm⁻² with a 1 M NaCl electrolyte over 5000 cycles underscores the potential of IC-LIG electrodes as a sustainable solution for advanced energy storage devices and beyond.

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Guido Panzarasa

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