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Mycelium-Based Composite Materials: Study of Acceptance
Mycelium-based composites (MBCs) are alternative biopolymers for designing sustainable furniture and other interior elements. These innovative biocomposites have many ecological advantages but present a new challenge in aesthetics and human product acceptance. Grown products, made using living mycelium and lignocellulosic substrates, are porous, have irregular surfaces and have irregular coloring. The natural origin of these types of materials and the fear of fungus can be a challenge. This research investigated the level of human acceptance of the new material. Respondents were students of architecture who can be considered as people involved in interior design and competent in the design field. Research has been performed on the authors’ prototype products made from MBCs. Three complementary consumer tests were performed. The obtained results measured the human reactions and demonstrated to which extents products made of MBCs were “likeable” and their nonobvious aesthetics were acceptable to the public. The results showed that MBC materials generally had a positive or not-negative assessment. The responses after the pairwise comparison of the MBC with wall cladding samples pointed out the advantage of ceramic reference material above the MBC based on an overall assessment. The respondents also believed that the chamotte clay cladding would be easier to fit into the aesthetics of a modern interior and would in better accordance with its style. Although the MBC was less visually appealing, the respondents nevertheless found it more interesting, original, and environmentally friendly. The experiments suggested that the respondents had double standards regarding MBCs. MBCs were generally accepted as ecological, but not in their own homes. All of these results support current and future applications of MBCs for manufacturing items where enhanced aesthetics are required.
Mycelium-Based Composites in Art, Architecture, and Interior Design: A Review
Mycelium-based composites (MBCs) have attracted growing attention due to their role in the development of eco-design methods. We concurrently analysed scientific publications, patent documents, and results of our own feasibility studies to identify the current design issues and technologies used. A literature inquiry in scientific and patent databases (WoS, Scopus, The Lens, Google Patents) pointed to 92 scientific publications and 212 patent documents. As a part of our own technological experiments, we have created several prototype products used in architectural interior design. Following the synthesis, these sources of knowledge can be concluded: 1. MBCs are inexpensive in production, ecological, and offer a high artistic value. Their weaknesses are insufficient load capacity, unfavourable water affinity, and unknown reliability. 2. The scientific literature shows that the material parameters of MBCs can be adjusted to certain needs, but there are almost infinite combinations: properties of the input biomaterials, characteristics of the fungi species, and possible parameters during the growth and subsequent processing of the MBCs. 3. The patent documents show the need for development: an effective method to increase the density and the search for technologies to obtain a more homogeneous internal structure of the composite material. 4. Our own experiments with the production of various everyday objects indicate that some disadvantages of MBCs can be considered advantages. Such an unexpected advantage is the interesting surface texture resulting from the natural inhomogeneity of the internal structure of MBCs, which can be controlled to some extent.
Valorization of Forest Biomass Through Pyrolysis: A Study on the Energy Potential of Wood Tars
Forest biomass is a renewable source of environmentally friendly material—wood. However, wood processing generates large amounts of by-products, including branches. These byproducts are often used as firewood; however, they can be used much more effectively. In this study, the pyrolysis of two woods, namely birch and pine, was proposed. The liquid products of pyrolysis were studied by FTIR spectroscopy, and the heating value of these products was evaluated. In order to find the optimal pyrolysis temperature from the point of view of the calorific value of the product, the process was carried out at four temperatures: 450, 500, 550, and 600 °C. The liquid product yielded three fractions, from which two were analyzed, namely the dense tar fraction and light liquid fraction. FTIR analysis results clearly demonstrated that samples from different fractions differ from one another, yet the results within the same fraction are remarkably similar. The tar fraction was characterized with a higher gross calorific value between 42 to 50 MJ/kg, while the liquid fraction gross calorific value was between 29 and 39 MJ/kg; in general, pine wood yielded products with higher calorific values. The pyrolysis of small wood industry by-products is an interesting method of utilization, yielding not only a liquid product with good calorific properties, but also a solid product, namely biochar, which may be used in carbon storage or used as a soil amendment.
Correction: Physical and mechanical properties of wood treated with chitosan-caffeine formulations
Fungi in Mycelium-Based Composites: Usage and Recommendations
Mycelium-Based Composites (MBCs) are innovative engineering materials made from lignocellulosic by-products bonded with fungal mycelium. While some performance characteristics of MBCs are inferior to those of currently used engineering materials, these composites nevertheless prove to be superior in ecological aspects. Improving the properties of MBCs may be achieved using an adequate substrate type, fungus species, and manufacturing technology. This article presents scientifically verified guiding principles for choosing a fungus species to obtain the desired effect. This aim was realized based on analyses of scientific articles concerning MBCs, mycological literature, and patent documents. Based on these analyses, over 70 fungi species used to manufacture MBC have been identified and the most commonly used combinations of fungi species-substrate-manufacturing technology are presented. The main result of this review was to demonstrate the characteristics of the fungi considered optimal in terms of the resulting engineering material properties. Thus, a list of the 11 main fungus characteristics that increase the effectiveness in the engineering material formation include: rapid hyphae growth, high virulence, dimitic or trimitic hyphal system, white rot decay type, high versatility in nutrition, high tolerance to a substrate, environmental parameters, susceptibility to readily controlled factors, easy to deactivate, saprophytic, non-mycotoxic, and capability to biosynthesize natural active substances. An additional analysis result is a list of the names of fungus species, the types of substrates used, the applications of the material produced, and the main findings reported in the scientific literature.
Synthesis and structural characteristic of pyridine carboxylic acid adducts with squaric acid
Squaric acid was used as a coformer to pyridine carboxylic acid cocrystallization. Adducts were obtained by evaporation from solution. Spectroscopic and theoretical studies were also performed. Thermal analysis reveals the high thermal stability of the obtained complexes.
Comparison of the properties of birch bark tar obtained by the double-clay pot method and the laboratory method
Interaction of amantadine with squaric acid and water; Crystal structure, spectroscopic and DFT analysis
Activity of Viscum album L. extract against wood-rot fungi and its potential application in wood preservation
Indole Derivatives Bearing Imidazole, Benzothiazole-2-Thione or Benzoxazole-2-Thione Moieties—Synthesis, Structure and Evaluation of Their Cytoprotective, Antioxidant, Antibacterial and Fungicidal Activities
In the search for new bioactive compounds, a methodology based on combining two molecules with biological properties into a new hybrid molecule was used to design and synthesize of a series of ten indole derivatives bearing imidazole, benzothiazole-2-thione, or benzoxazole-2-thione moieties at the C-3 position. The compounds were spectroscopically characterized and tested for their antioxidant, antibacterial, and fungicidal activities. The crystal structures were determined for five of them. Comparison of the closely related structures containing either benzothiazole-2-thione or benzoxazole-2-thione clearly shows that the replacement of -S- and -O- ring atoms modify molecular conformation in the crystal, changes intermolecular interactions, and has a severe impact on biological activity. The results indicate that indole-imidazole derivatives with alkyl substituent exhibit an excellent cytoprotective effect against AAPH-induced oxidative hemolysis and act as effective ferrous ion chelating agents. The indole-imidazole compound with chlorine atoms inhibited the growth of fungal strains: Coriolus versicolor (Cv), Poria placenta (Pp), Coniophora puteana (Cp), and Gloeophyllum trabeum (Gt). The indole-imidazole derivatives showed the highest antibacterial activity, for which the largest growth-inhibition zones were noted in M. luteus and P. fluorescens cultures. The obtained results may be helpful in the development of selective indole derivatives as effective antioxidants and/or antimicrobial agents.
Bioactive Propolis-Silane System as Antifungal Agent in Lignocellulosic-Polymer Composites
Polymer composites with renewable lignocellulosic fillers, despite their many advantages, are susceptible to biodegradation, which is a major limitation in terms of external applications. The work uses an innovative hybrid propolis-silane modifier in order to simultaneously increase the resistance to fungal attack, as well as to ensure good interfacial adhesion of the filler–polymer matrix. Polypropylene composites with 30% pine wood content were obtained by extrusion and pressing. The samples were exposed to the fungi: white-rot fungus Coriolus versicolor, brown-rot fungus Coniophora puteana, and soft-rot fungus Chaetomium globosum for 8 weeks. Additionally, biological tests of samples that had been previously exposed to UV radiation were carried out, which allowed the determination of the influence of both factors on the surface destruction of composite materials. The X-ray diffraction, attenuated total reflectance–Fourier transform infrared spectroscopy, and mycological studies showed a significant effect of the modification of the lignocellulose filler with propolis on increasing the resistance to fungi. Such composites were characterized by no changes in the supermolecular structure and slight changes in the intensity of the bands characteristic of polysaccharides and lignin. In the case of systems containing pine wood that had not been modified with propolis, significant changes in the crystalline structure of polymer composites were noted, indicating the progress of decay processes. Moreover, the modification of the propolis-silane hybrid system wood resulted in the inhibition of photo- and biodegradation of WPC materials, as evidenced only by a slight deterioration in selected strength parameters. The applied innovative modifying system can therefore act as both an effective and ecological UV stabilizer, as well as an antifungal agent.
Resistance of Kapok Fibers (Ceiba pentandra) to Biotic and Abiotic Degradation: Evaluation by SEM, FTIR, Py-GC/MS, and Colorimetry
Chitosan–caffeine formulation as an ecological preservative in wood protection
AbstractNowadays, taking into account environmental degradation, climate changes, as well as, environmentally friendly regulations and increasing ecological awareness of consumers, methods of wood protection without negative impact on the environment are being intensively developed. In this study, a mixture of chitosan and caffeine was proposed as ecological wood preservative. The aim of the research was to evaluate the application of chitosan (medium and high molecular weight) as an agent limiting the leaching of caffeine from the structure of treated wood. The resistance of pine wood treated with chitosan–caffeine preparations and ingredients of these preparations (caffeine and chitosan) to brown rot fungus—Coniophora puteana was assessed. The degree of caffeine leaching from the treated wood was determined by chromatographic analysis (caffeine concentration) and elemental analysis (nitrogen concentration). The results showed that chitosan limited caffeine leaching from wood, which was confirmed by chromatographic analysis and changes in the wood structure observed in FTIR spectra. Moreover, wood treated with chitosan–caffeine preparations showed resistance against C. puteana (mass loss about 0.5%); however, antifungal activity was reduced when treated wood was subjected to leaching with water (mass loss about 10%). The obtained results suggest that the chitosan–caffeine preparations can be promising ecological preservatives for the wood treatment.