Iron-Catalyzed Laser-Induced Graphitization - Multiscale Analysis of the Structural Evolution and Underlying Mechanism.

The transition to sustainable materials and eco-efficient processes in commercial electronics is a driving force in developing green electronics. Iron-catalyzed laser-induced graphitization (IC-LIG) has been demonstrated as a promising approach for rendering biomaterials electrically conductive. To optimize the IC-LIG process and fully exploit its potential for future green electronics, it is crucial to gain deeper insights into its catalyzation mechanism and structural evolution.

Methylene glycol-sulfite pH-clocks for the time-programming of soft materials: advantages, limitations, and yet unexplored opportunities.

Coupling nonlinear reaction networks with soft matter building blocks holds great potential for the design of life-mimicking, time-programmable dissipative self-assembly systems. In this regard, clock reactions are especially useful triggers since they allow to autonomously generate chemical stimuli such as pH changes. The methylene glycol-sulfite (MGS) is a well-known acid-to-base pH-clock reaction which is able to produce sharp and intense pH jumps (up to 5 pH units) after a reliable, yet relatively short (tens of seconds rather than minutes), induction time.

Chemiluminescent wood.

Wood materials incorporating new properties are of great interest, especially for advanced applications such as sustainable optics and photonics. In this work we describe a wood functionalization approach, comprising the incorporation of artificial chemiluminescent systems (phenyl oxalate ester‑hydrogen peroxide-fluorophore, and luminol-ferricyanide), resulting in light-emitting wood. By a detailed characterisation of the light emission features we point out the complex interaction between wood scaffold and chemiluminescent systems, especially the quenching effect of wood extractives (for the TCPO-HO-fluorophore system) and lignin (for the luminol-ferricyanide system).

Time-domain Tollens reaction: synthesising silver nanoparticles with the formaldehyde clock.

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.

Sustainability in Wood Products: A New Perspective for Handling Natural Diversity.

Wood is a renewable resource with excellent qualities and the potential to become a key element of a future bioeconomy. The increasing environmental awareness and drive to achieve sustainability is leading to a resurgence of research on wood materials. Nevertheless, the global climate changes and associated consequences will soon challenge the wood-value chains in several regions (e.

Passive climate regulation with transpiring wood for buildings with increased energy efficiency.

Buildings are significant end-users of global energy. About 20% of the energy consumption worldwide is used for maintaining a comfortable indoor climate. Therefore, passive systems for indoor temperature and humidity regulation that can respond to environmental changes are very promising to reduce buildings' energy consumption.

Formation of Iron (Hydr)Oxide Nanoparticles with a pH-Clock.

We demonstrate the autonomous synthesis of iron (hydr)oxide (green rust, magnetite, and lepidocrocite) nanoparticles by precipitating iron(II) ions using hydroxide ions generated in situ with the methylene glycol-sulfite (MGS) reaction, a pH-clock. We show that the nature of the products can be predetermined by tuning the initial iron(II) concentration.

Emerging Engineered Wood for Building Applications.

The building sector, including building operations and materials, was responsible for the emission of ∼11.9 gigatons of global energy-related CO in 2020, accounting for 37% of the total CO emissions, the largest share among different sectors. Lowering the carbon footprint of buildings requires the development of carbon-storage materials as well as novel designs that could enable multifunctional components to achieve widespread applications.

Sustainable wood electronics by iron-catalyzed laser-induced graphitization for large-scale applications.

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.

Thermoresponsive Smart Gating Wood Membranes.

Smart membranes that can open and/or close their pores in a controlled manner by external stimuli possess potential in various applications, such as water flow manipulation, indoor climate regulation, and sensing. The design of smart gating membranes with high flux, immediate response, and mechanical robustness is still an open challenge, limiting their versatility and practical applicability. Inspired by the controlled opening and closure of plant stomata, we have developed a smart gating wood membrane, taking advantage of the unique wood scaffold with its hierarchical porous structure to carry thermoresponsive hydrogel gates.

Dissolution of Zinc Oxide Nanoparticles in the Presence of Slow Acid Generators.

We describe a preliminary investigation of the dissolution dynamics of zinc oxide nanoparticles in the presence of cyclic esters (δ-gluconolactone and propanesultone) as slow acid generators. The particles dissolution is monitored by means of turbidimetry and correlated with the evolution of pH over time. The results could be of interest for the design of chemically programmable colloidal systems.

Natural Wood-Based Catalytic Membrane Microreactors for Continuous Hydrogen Generation.

The development of controlled processes for continuous hydrogen generation from solid-state storage chemicals such as ammonia borane is central to integrating renewable hydrogen into a clean energy mix. However, to date, most reported platforms operate in batch mode, posing a challenge for controllable hydrogen release, catalyst reusability, and large-scale operation. To address these issues, we developed flow-through wood-based catalytic microreactors, characterized by inherent natural oriented microchannels.

Structural color from solid-state polymerization-induced phase separation.

Structural colors are produced by wavelength-dependent scattering of light from nanostructures. While living organisms often exploit phase separation to directly assemble structurally colored materials from macromolecules, synthetic structural colors are typically produced in a two-step process involving the sequential synthesis and assembly of building blocks. Phase separation is attractive for its simplicity, but applications are limited due to a lack of robust methods for its control.

Enhanced mechanical energy conversion with selectively decayed wood.

Producing electricity from renewable sources and reducing its consumption by buildings are necessary to meet energy and climate change challenges. Wood is an excellent "green" building material and, owing to its piezoelectric behavior, could enable direct conversion of mechanical energy into electricity. Although this phenomenon has been discovered decades ago, its exploitation as an energy source has been impaired by the ultralow piezoelectric output of native wood.

Supramolecular gelation controlled by an iodine clock.

Programming supramolecular assembly in the time domain is a fundamental aspect of the design of biomimetic materials. We achieved the time-controlled sol-gel transition of a poly(vinyl alcohol)-iodine supramolecular complex by generating iodine in situ with a clock reaction. We demonstrate that both the gelation time and the mechanical properties of the resulting hydrogel can be tuned by properly selecting the clock parameters or through competitive iodine complexation.

Sustainable and Biodegradable Wood Sponge Piezoelectric Nanogenerator for Sensing and Energy Harvesting Applications.

Developing low-cost and biodegradable piezoelectric nanogenerators is of great importance for a variety of applications, from harvesting low-grade mechanical energy to wearable sensors. Many of the most widely used piezoelectric materials, including lead zirconate titanate (PZT), suffer from serious drawbacks such as complicated synthesis, poor mechanical properties (e.g.

Oscillating Reactions Meet Polymers at Interfaces.

Chemo-mechanical phenomena, including oscillations and peristaltic motions, are widespread in nature-just think of heartbeats-thanks to the ability of living organisms to convert directly chemical energy into mechanical work. Their imitation with artificial systems is still an open challenge. Chemical clocks and oscillators (such as the popular Belousov-Zhabotinsky (BZ) reaction) are reaction networks characterized by the emergence of peculiar spatiotemporal dynamics.

Transient supramolecular assembly of a functional perylene diimide controlled by a programmable pH cycle.

Self-regulating materials require embedded control systems. Active networks of enzymes fulfill this function in living organisms, and the development of chemical controls for synthetic systems is still in its infancy. While previous work has focused on enzymatic controls, small-molecule networks have unexplored potential.

The horseradish smile: Demonstrating characteristic reactions of peroxidase in a visually appealing way.

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.

Pyranine-Modified Amphiphilic Polymer Conetworks as Fluorescent Ratiometric pH Sensors.

The fluorescent dye 8-hydroxypyrene-1,3,6-trisulfonate (pyranine) combines high photostability with ratiometric pH detection in the physiological range, making it a prime candidate for optical sensors in biomedical applications, such as pH-based chronic wound monitoring. However, pyranine's high water solubility and the difficulty of covalent attachment pose severe limitations in terms of leaching from sensor matrices. Herein, pyranine-modified nanophase-separated amphiphilic polymer conetworks (APCNs) are reported as fluorescent ratiometric pH sensors.

Just Add Luminol to Turn the Spotlight on Radziszewski Amidation.

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.

Impact of in situ acid generation and iodine sequestration on the chlorite-iodide clock reaction.

Acid generators, such as cyclic esters, have recently emerged as powerful modulators of clock reactions. Here, we show that a transient pH burst emerges when δ-gluconolactone is coupled to the chlorite-iodide reaction. The timing and strength of the bursts depend on the concentration of the cyclic ester and can be further modulated by sequestration of iodine by tetrabutylammonium cations or α-cyclodextrin.

Scalable Biosynthesis of Melanin by the Basidiomycete Armillaria cepistipes.

Natural melanin features many interesting properties, including the ability to shield electromagnetic radiation, the ability to act as scavenger for radical and reactive oxygen species and the capacity to chelate different metal ions. For these reasons, melanin is becoming increasingly relevant for the development of functional materials with potential applications in cosmetics, drug delivery, and water purification. However, the extraction and purification of melanin from conventional sources (e.

Lanthanide-Doped Hafnia Nanoparticles for Multimodal Theranostics: Tailoring the Physicochemical Properties and Interactions with Biological Entities.

High-Z metal oxide nanoparticles hold promise as imaging probes and radio-enhancers. Hafnium dioxide nanoparticles have recently entered clinical evaluation. Despite promising early clinical findings, the potential of HfO as a matrix for multimodal theranostics is yet to be developed.