Diatoms are unicellular photosynthetic microalgae, ubiquitously diffused in both marine and freshwater environments, which exist worldwide with more than 100 000 species, each with different ...morphologies and dimensions, but typically ranging from 10 to 200 µm. A special feature of diatoms is their production of siliceous micro‐ to nanoporous cell walls, the frustules, whose hierarchical organization of silica layers produces extraordinarily intricate pore patterns. Due to the high surface area, mechanical resistance, unique optical features, and biocompatibility, a number of applications of diatom frustules have been investigated in photonics, sensing, optoelectronics, biomedicine, and energy conversion and storage. Current progress in diatom‐based nanotechnology relies primarily on the availability of various strategies to isolate frustules, retaining their morphological features, and modify their chemical composition for applications that are not restricted to those of the bare biosilica produced by diatoms. Chemical or biological methods that decorate, integrate, convert, or mimic diatoms' biosilica shells while preserving their structural features represent powerful tools in developing scalable, low‐cost routes to a wide variety of nanostructured smart materials. Here, the different approaches to chemical modification as the basis for the description of applications relating to the different materials thus obtained are presented.
Nanostructured biosilica shells of diatoms can be used as materials for drug delivery, biosensing, catalysis, and optoelectronics. Chemical modification enables their properties to be tailored for specific applications. An overview of the manifold routes to diatom biosilica functionalization is provided, covering chemical protocols, in vivo approaches, and genetic mutation, with an emphasis on possibilities offered by the resulting hybrid materials.
In this article we highlight, by means of selected examples drawn from work performed in our or other laboratories, the features of some classes of fluorinated conjugated materials and their use in ...electronic devices such as electroluminescent diodes or field effect transistors. A variety of fluorinated conjugated systems, either molecular or polymeric, such as poly(phenylenevinylene)s, poly(phenyleneethynylene)s, polythiophenes, polyphenylenes, are dealt with. Attention is also focused on a different class of electroluminescent compounds, represented by the cyclometalated iridium complexes with various forms (mer and fac). In particular, fluorine atoms lower both the HOMO and LUMO energy levels. Consequently, the electron injection is made easier, the materials display a greater resistance against the degradative oxidation processes and organic n-type or ambipolar semiconducting materials may result. Moreover, the C-H...F interactions play an important role in the solid state supramolecular organization, originating a typical pi-stack arrangement which enhances the charge carrier mobility.
Fully substituted triazoles are synthesized by a sustainable direct arylation reaction performed under solvent‐free conditions and in the presence of a recyclable Pd/C heterogeneous catalyst. ...Exclusion of air as well as anhydrous conditions are not required, enabling a convenient synthesis of 1,4,5‐trisubstituted 1,2,3‐triazoles and 1,2,3‐triazole‐fused isoindolines starting from 1,4‐disubstituted 1,2,3‐triazoles, easily prepared via click chemistry, and functionalized aryl iodides.
1,4,5‐Trisubstituted 1,2,3‐triazoles and 1,2,3‐triazole‐fused isoindolines are synthesized by a sustainable Pd‐catalyzed direct arylation reaction performed under solvent‐free conditions and in the presence of a recyclable heterogeneous catalyst.
To celebrate the 40 year anniversary of the Giacomo Ciamician Medal EurJOC invited the past awardees of this prestigious prize to contribute an article to this Special Collection. Guest Editor ...Gianluca M. Farinola introduces the significance of the Giacomo Ciamician Medal.
To celebrate the 40 year anniversary of the Giacomo Ciamician Medal EurJOC invited the past awardees of this prestigious prize to contribute an article to this Special Collection. Guest Editor Gianluca M. Farinola introduces the significance of the Giacomo Ciamician Medal.
A critical selection of the recent literature reports on the use of photosynthetic and photoresponsive bacteria as a source of materials for optoelectronics and photonic devices is discussed, ...together with the applications foreseen in solar energy conversion and storage and light information technologies. The use of both photoactive cellular components and entire living cells is reviewed, aiming to highlight the great conceptual impact of these studies. These studies point out possible deep changes in the paradigm of design, and synthesis of materials and devices for optoelectronics. Although the possible technological impact of this technology is still hard to be predicted, these studies advance the understanding of photonics of living organisms and develop new intriguing concepts in biomaterials research.
Photosynthetic and photoresponsive bacteria can be used as a source of materials for optoelectronics and photonics. Applications of either photoactive cellular components or metabolically active photosynthetic bacterial cells in devices for solar energy conversion and storage and in light information technologies are presented. Emphasis on new concepts in materials design and device architectures emerging from recent research is given.
The exceptional underwater adhesive properties displayed by aquatic organisms, such as mussels (Mytilus spp.) and barnacles (Cirripedia spp.) have long inspired new approaches to adhesives with a ...superior performance both in wet and dry environments. Herein, a bioinspired adhesive composite that combines both adhesion mechanisms of mussels and barnacles through a blend of silk, polydopamine, and Fe3+ ions in an entirely organic, nontoxic water‐based formulation is presented. This approach seeks to recapitulate the two distinct mechanisms that underpin the adhesion properties of the Mytilus and Cirripedia, with the former secreting sticky proteinaceous filaments called byssus while the latter produces a strong proteic cement to ensure anchoring. The composite shows remarkable adhesive properties both in dry and wet conditions, favorably comparing to synthetic commercial glues and other adhesives based on natural polymers, with performance comparable to the best underwater adhesives with the additional advantage of having an entirely biological composition that requires no synthetic procedures or processing.
New mussel‐inspired, high‐performance underwater adhesive is developed using Bombyx mori silk fibroin as protein backbone and polydopamine as catechol bearing molecule. This all‐natural synthetic‐step free composition displays in lap‐shearing bonding tests underwater adhesion forces (2.6 MPa) that rival commercial synthetic adhesives.
Paper is a flexible material, commonly used for information storage, writing, packaging, or specialized purposes. It also has strong appeal as a substrate in the field of flexible printed ...electronics. Many applications, including safety, merchandising, smart labels/packing, and chemical/biomedical sensors, require an energy source to power operation. Here, progress regarding development of photovoltaic and energy storage devices on cellulosic substrates, where one or more of the main material layers are deposited via solution processing or printing, is reviewed. Paper can be used simply as the flexible substrate or, exploiting its porous fiber‐like nature, as an active film by infiltration or copreparation with electronic materials. Solar cells with efficiencies of up to 9% on opaque substrates and 13% on transparent substrates are demonstrated. Recent developments in paper‐based supercapacitors and batteries are also reviewed with maximum achieved capacity of 1350 mF cm−2 and 2000 mAh g−1, respectively. Analyzing the literature, it becomes apparent that more work needs to be carried out in continuing to improve peak performance, but especially stability and the application of printing techniques, even roll‐to‐roll processing, over large areas. Paper is not only environmentally friendly and recyclable, but also thin, flexible, lightweight, biocompatible, and inexpensive.
The progress regarding development of solar cells and energy storage devices on paper substrates, where one or more of the main material layers are deposited via solution processing or printing, is reviewed. Paper is not only environmentally friendly and recyclable, but also thin, flexible, lightweight, biocompatible, inexpensive, and appealing as a substrate in the field of flexible printed electronics.
Direct arylation of 5-octylthieno3,4-cpyrrole-4,6-dione with a series of functionalized aryl iodides via C–H bond activation is demonstrated in a deep eutectic solvent made of choline chloride and ...urea in non-anhydrous conditions and without exclusion of air. This is the first demonstration of a thiophene–aryl coupling via direct arylation in deep eutectic solvents.
This review covers our recent contribution on the synthesis of extended polyconjugated compounds, such as conjugated polymers and small molecules. The synthetic strategies developed in our research ...group are mainly based on palladium‐catalyzed cross‐coupling reactions involving a variety of organometallic intermediates as well as on direct arylation reactions via C–H functionalization. This report is organized according to the synthetic methods used (coupling of unsaturated organosilanes, Suzuki–Miyaura cross‐coupling, Stille cross‐coupling, direct arylation) and the typologies of the structures synthesized (polymers, small molecules).
Extended conjugated structures have been synthesized by protocols based on the palladium‐catalyzed cross‐coupling reactions, involving organometallic intermediates, such as boron, and tin organic reagents, as well as by direct arylation reactions through C–H functionalization.
Diatoms microalgae can be regarded as living factories producing nanostructured and mesoporous biosilica shells (frustules) having a highly ordered hierarchical architecture. These unique, ...morphological, chemical and mechanical properties make diatoms’ biosilica a very attractive nanomaterial for a wide variety of applications. Methods of purification of frustules that preserve their nanostructured morphology have been set up as well as in vivo or in vitro chemical modification protocols of the biosilica with functional molecules to generate biohybrid active materials for photonics, sensing, drug delivery and electronics. Herein we describe, with some selected examples, the great variety of applications envisaged for native and modified frustules, highlighting the material scientists’ benefit to avail of nature in the construction of highly ordered biohybrid architectures for nanotechnology. New concepts for the biotechnological production of nanomaterials are opened by the use of diatoms as living factories.
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