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Sunflower ( Helianthus annuus ) represents one of the most successful agricultural crops, typically grown for vegetable oil production, mostly used for food applications. In this review, the application of various products derived from parts of sunflower plants other than the seed cotyledon in the manufacturing of sustainable composites is considered. In particular, three concurring systems are here intersected with variable degrees of evidence. These are respectively built on seed residues as hardening fillers, on plant bast for lignocellulosic fibre/particles production, and on sunflower oil for bio-resin development. Data reported from literature indicate that seed husk does constitute a present and valuable resource, being necessarily separated during the oil production process. In contrast, the use of sunflower stems with their typical three-parted structure, including epidermis, fibrous secondary structure, and internal xylem, though offering a variety of behaviours, is still poorly exploited. As regards excess sunflower oil production, its use in the synthesis of alkyd or epoxy resins from triglycerides remains largely germinal, while the development of bio-polyurethanes using sunflower polyols has received limited attention so far. In spite of these caveats, the strength of the productive system based on sunflower cultivation and the abundance of raw matter suggest that in the future all these sectors will expand and be competitive with other sources for the production of biomass composites. In particular, this review, despite the literature gaps, tries to elucidate which issues hinder the eventual production of an all-sunflower composite (bio-matrix, cellulose fibres and ligneous fillers) in the near future, which could be an example of industrial product from a single cultivation chain.

The growing demand for sustainable materials has driven the exploration of natural fibers as eco-friendly alternatives to synthetic reinforcements for composites. This study investigates the potential of Posidonia oceanica, an abundant marine biomass, which is often driven to be stacked on the backshore and used so far for energy recovery and low-value applications, as a filler and possible reinforcement in cementitious and polymer composites. Most applications of Posidonia are concentrated in the Mediterranean area and focused on the construction industry. However, its introduction in polymer composites, especially as a source of cellulose or in combination with the use of bio-based matrices, can also be proposed. With this aim, the physical and chemical properties of Posidonia oceanica fibers need to be characterized, and their compatibility with various matrices needs to be evaluated. Experimental results demonstrate that Posidonia oceanica fibers, especially when treated with alkali and silane, or combining both treatments, can exhibit mechanical properties quite comparable to other natural fibers, namely to those obtained from grass species. As with any other type of waste, yet with more interest for its wide accumulation over the coastal line, the use of Posidonia oceanica in composites may contribute to reducing the environmental footprint of these materials, aligning with circular economy principles. This review highlights the dual benefits of utilizing marine biomass by advancing material sustainability while not being detrimental to coastal waste management.

Direct (hetero)arylation (DHA) is playing a key role in improving the efficiency and atom economy of C–C cross coupling reactions, so has impacts in pharmaceutical and materials chemistry. Current research focuses on further improving the generality, efficiency and selectivity of the method through careful tuning of the reaction conditions and the catalytic system. Comparatively fewer studies are dedicated to the replacement of the high-boiling-point organic solvents dominating the field and affecting the overall sustainability of the method. We show herein that the use of a 9:1 v/v emulsion of an aqueous Kolliphor 2 wt% solution while having toluene as the reaction medium enables the preparation of relevant examples of thiophene-containing π-conjugated building blocks in high yield and purity.

Keratin, a structural protein with outstanding mechanical and biochemical properties, is abundant in animal‐derived wastes such as feathers, wool, and hooves. However, these keratin‐rich materials are still largely incinerated or landfilled, leading to environmental burdens and resource loss. This review introduces horse hoof trimmings as an unexploited, renewable, and cruelty‐free keratin source generated through routine equine care. Unlike slaughter‐derived materials, hoof trimmings provide a traceable and high‐quality biopolymer feedstock with the potential for sustainable valorization. We summarize current knowledge on their chemical composition, structure, and physicochemical properties, highlighting correlations with nutrition, environment, and management practices. Furthermore, we critically assess green extraction methods and upcycling strategies for keratin recovery, identifying challenges and opportunities for scaling toward industrial applications. By focusing on this overlooked waste stream, this review aims to stimulate innovation in sustainable materials chemistry, biopolymer engineering, and circular resource management, advancing the principles of green and circular chemistry. This review outlines horse hooves as an overlooked, sustainable source of cruelty‐free keratin. It synthesizes current insights into their structure, composition, and properties and highlights the main extraction methods, emphasizing their sustainability and the material's potential applications.

Field handheld/portable instrumentations, such as in-situ geochemical analyzers, have the potential to assist efficiently targeted geochemical archaeometry campaigns in detecting and quantifying specific elements. Non-destructive portable energy dispersive x-ray fluorescence and micro-destructive handheld laser-induced breakdown spectroscopy (LIBS) instrumentation were utilized to investigate the elemental composition, internal stratigraphy by depth profiling and microscale compositional mapping of five copper and two iron alloy artefacts collected from various ancient graves in the Minervino Murge area, Apulia, Italy. The primary elements identified by both techniques included Cu, Sn and Pb in copper alloys, and Fe with minor amounts of Cu and Pb in iron alloys. Furthermore, the elements Al, Ca, Si, Mg, Na and K, mostly originated from soil contamination, and the trace elements Sb, Ni and Zn were detected. The satisfactory performance of both techniques was assessed by their capacity to provide reproducible elemental composition data. Finally, the depth profile and mapping achieved by LIBS contributed to understanding the metal processing and history of the objects studied, so confirming both techniques to be robust analytical tools in outdoor archaeology and archaeometry campaigns.

Doped organic semiconductors play a central role in the development of several innovative optoelectronic and energy harvesting applications. Currently, the realization of thermoelectric generators, which require both hole‐ and electron‐transporting materials with high electrical conductivity, is strongly hindered by the scarce availability of stable solution‐processable n‐dopants and their limited efficiency. Herein, the synthesis of 4‐(1,3‐dimethyl‐2,3‐dihydro‐1H‐benzimidazol‐2‐yl)‐dibenzazepine (IStBI), a novel derivative belonging to the well‐known family of the benzimidazoline compounds, is presented. The functionalization with the planarized and rigid iminostilbene substituent allows, without significantly affecting the compound electronic structure, an efficient intercalation of the dopant molecules inside the ordered regions of thin films of the benchmark n‐type polymer poly(N,N′‐bis‐2‐octyldodecylnaphthalene‐1,4,5,8‐bis‐dicarboximide‐2,6‐diyl‐alt‐5,5′‐2,2′‐bithiophene) P(NDI2OD‐T2). Consequently, a maximum electrical conductivity of (1.14 ± 0.13) × 10−2 S cm−1 is recorded, exceeding by one order of magnitude what previously achieved upon solution doping of the reference P(NDI2OD‐T2) with benzimidazoline derivatives. The thermoelectric power factor is also simultaneously increased. The findings confirm that tailoring of the dopant chemical structure to improve structural interactions with the host semiconductors can be employed as a successful strategy to achieve more effective n‐doping, helping to close the performance gap with p‐type materials. The development of organic thermoelectric generators requires better performing molecular n‐type dopants. The synthesis of a novel benzimidazoline derivative functionalized with a rigid and planarized iminostilbene substituent is reported here. Such chemical modification emerges as a feasible strategy to enhance the electrical conductivity and the thermoelectric performances of semiconducting polymeric blends, favoring dopant intercalation inside the host semicrystalline matrix.

This research explores the potential introduction of marine waste-derived biological fillers within bio-epoxy matrices to mitigate the environmental impact of traditional materials, like fiberglass, in boat construction. However, this raises concerns about biofouling and degradation, issues that have not been extensively investigated in composites, especially over a time frame representative of issues that could arise during service. Although protective solutions like biocides and specific coatings exist, degradation remains challenging when attempting to use eco-friendly natural fillers. This study specifically integrates various biological fillers, namely ceramics (mussel, oyster, clam powder) or ligno-cellulosic (i.e., Posidonia oceanica fibers) into epoxy for use in some boat components (bench seats for the bridge deck), aiming to evaluate the biofouling process under extreme (or decommissioning) conditions. In itself, epoxy does represent an ideal enclosing matrix for biomass waste, which ideally needs to be introduced in significant amounts. The development of biofouling in the specific context of Kotor’s Bay, Montenegro, for a duration of six months, and relevant composite degradation were examined. In particular, three situations were reproduced by positioning the samples in a harbor environment: (i) on the bottom of the sea (2 m. depth), (ii) immersed just below the surface (0.5 m. depth), and (iii) on the splashing surface (pier). The concerns identified appear generally limited in the case of the envisaged application, despite some significant wear effect in the case of the samples containing Posidonia. However, this study also offers information and caveats in terms of more ambitious prospective applications (e.g., the boat hull structure).

Bio-epoxy composites were fabricated by casting a resin–hardener–filler mixture into 3D-printed molds, using different sea-originated secondary raw materials: mussel shell powder (MSP) (63–83 μm) and Posidonia oceanica short fibers (POF) (1–2 mm). Monofiller composites were prepared with 5 or 10 wt.% MSP, or 5 or 10 wt.% POF. Hybrid formulations were also produced, containing both MSP and POF in two combinations, where the total amount of filler again summed up at 10 wt.%. A subset of the samples was conditioned by immersion in a 35 ‰ NaCl solution reproducing seawater composition until saturation was reached. Characterization was carried out on unconditioned and conditioned samples by Shore D hardness and Charpy impact tests while performing three-point flexural loading only on unconditioned ones. Fracture morphology was also investigated. Adding MSP slightly enhanced resin hardness, whereas impact absorption exhibited, to a variable extent, a two-phase behavior, reproducing crack initiation and propagation. The MSP6-POF4 hybrid configuration provided the greatest improvement in absorbed energy (25–30% higher), which was retained after conditioning. The introduction of fillers, first separately, then in combination, resulted in a reduction in flexural strength to a similar extent for all unconditioned configurations. Finally, composite panels containing 10 wt.% MSP, 10 wt.% POF, and a 6MSP–4POF hybrid formulation, intended for prospective boat deck applications, were fabricated and compared with neat bio-epoxy, showing satisfactory consolidation. Density and post-molding dimensional shrinkage were measured on the panels.

Taking a widely contaminated yet abundant waste, such as poultry feathers, and extracting keratin from this structure appears to be a real challenge whenever the preservation of the secondary structure of the protein is desired. This process would allow exploiting it in ways (e.g., in the biomedical field) that are inspired by a structure that is primarily designed for flight, therefore capable specifically of withstanding flexure and lateral buckling, also with very low thicknesses. The preservation of the structure is based on disulfide crosslinks, and it is offered with preference by some chemical treatments, mainly those based on ionic liquid and on a reduction process. However, the degree of preservation cannot always be precisely assessed; however, beyond chemical characterization, the formation of homogeneous gels can also suggest that the process was successful in this sense. An extraction respectful of nature’s intentions, considering that the secondary structure builds up according to the very function of the feathers in the animal, can be deemed to be biomimetic. In particular, biomimetic extractions comply with the very characteristics the protein was designed for to serve in the specific environmental and mechanical situation in which it is inserted. This review tries to elucidate in which cases this aim is achieved and for which specific applications a chicken feather keratin that has preserved its secondary structure can be suited.

In this work, the characteristic structure of keratin extracted from two different kinds of industrial waste, namely sheep wool and chicken feathers, using the sulfitolysis method to allow film deposition, has been investigated. The structural and microscopic properties have been studied by means of scanning electron microscopy (SEM), Raman spectroscopy, atomic force microscopy (AFM), and infrared (IR) spectroscopy. Following this, small-angle X-ray scattering (SAXS) analysis for intermediate filaments has been performed. The results indicate that the assembly character of the fiber can be obtained by using the most suitable extraction method, to respond to hydration, thermal, and redox agents. The amorphous part of the fiber and medium range structure is variously affected by the competition between polar bonds (reversible hydrogen bonds) and disulfide bonds (DB), the covalent irreversible ones, and has been investigated by using fine structural methods such as Raman and SAXS, which have depicted in detail the intermediate filaments of keratin from the two different animal origins. The preservation of the secondary structure of the protein obtained does offer a potential for further application of the waste-obtained keratin in polymer films and, possibly, biocomposites.