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In this work, polyurethane (PU) insulating panels containing different amounts of a microencapsulated paraffin with a nominal melting temperature of 24 °C, used as phase change material (PCM), were produced. The resulting panels behaved as multifunctional materials able to thermally insulate and simultaneously storing/releasing thermal energy near room temperature. The panels were characterized from a microstructural, thermal and mechanical point of view. Viscosity measurements highlighted an increase in the viscosity values of the PU liquid precursors due to the addition of the capsules, and this could lead to some difficulties during the production stages, especially in the mixing and foaming phases. From optical microscopy micrographs and density measurements, it was observed that the introduction of paraffin tended to destroy the cellular structure of PU foams, and for PCM contents above 30 mass/% the foams were characterized by an open-cell morphology. SEM observations showed that PCM was preferentially distributed in the cell walls intersection, and a rather limited interfacial adhesion between capsules and PU could be detected. Thermogravimetric analysis evidenced that the introduction of the PCM tended to increase the degradation resistance of the foams, while from differential scanning calorimetry tests it was possible to conclude that PCM addition was able to impart good thermal energy storage properties to the foams, with specific melting enthalpy values of 70 J g−1 for a microcapsules concentration of 50 mass/%. As expected, thermal conductivity (λ) of the foams increased with PCM amount, but this enhancement was not directly related to the higher λ of the PCM itself, but rather than to the cell opening effect promoted by the PCM introduction. The microcapsules addition progressively increased the stiffness of the foams, reducing the failure properties both under quasi-static and impact conditions. Moreover, the mechanical properties were strongly affected by the testing temperature (i.e. the physical state of the wax contained in the microcapsules).

To develop an activebiopolymerfilm based on chitosan, sodium caseinate, and rosemary essential oil (REO), the objective of this work was to investigate the effect of REO on the structure and physical properties of biopolymer films.Fourier transform infrared spectroscopywas conducted for fingerprinting to identify the REO addition. The thermal behaviour of each film was investigated using athermogravimetric analysis. Furthermore, the optical properties, surfacehydrophobicity, solubility, mechanical properties, and water vapour permeability were investigated. The results showed that the presence of REO changes the structural organisation of the blended sodium caseinate and chitosan film, thereby inducing an increase in the surface hydrophilicity of the film. However, the solubility and water vapour permeability of the film were not affected by the structural modification induced by REO. Moreover, a mild effect of the REO on the mechanical properties of the sodium caseinate/chitosan film was observed. A thermal analysis confirmed that the incorporation of REO did not influence the degradation temperature of the films. Overall this studying has demonstrated that caseinate/chitosan film enriched in REO, related to his thermal and chemico physical properties can be applied for food packaging application.

Plastic has become an essential part of our modern lifestyle and its global diffusion has led to a significant increase in the production of related waste, with obvious repercussions on the environment and on the entire sustainability chain. Recycling this kind of materials in the field of civil and industrial engineering is considered an ecological and economical solution due to the advantages it can offer. This paper represents the results of experimental investigations of mechanical strength, hygro-thermal and durability properties of two kinds of products: urban tiles (90 % PVC powder and 10 % polyurethane resin) and cement-based mortars reinforced with PVC compound coming out of electric cable protective sheath. The manufactured mortars were obtained by the volumetric substitution of the sand with five different percentages of plastic waste, from 10 % to 50 %. Plastic aggregates reduce density, causing a decrease in flexural and compressive strength of mortars. Nevertheless, the presence of plastic aggregate leads to a significant improvement of thermal insulation and shows a greater resistance to capillary water absorption compared to the reference one. The mechanical tests after two different cycles of accelerated solar aging of urban tiles demonstrated the feasibility of its use for external flooring (green parking). These results foster future studies about the development of increasingly eco-sustainable building materials.

Polyhedral oligomeric silsesquioxanes (POSSs), with Si vertices interconnected by –O– linkages, form three-dimensional nanometer size cage structures with substituents attached to silicon atoms. These substituents may contain reactive groups, such as hydroxyl or isocyanate. A combination of a rigid inorganic nanocore with organic vertex groups makes POSS molecules useful hybrid building blocks that can be chemically incorporated in the polymer matrix by copolymerization, grafting or reactive blending, or physically mixed by solvent casting or polymer processing by using, for example, the extrusion technique [1]. The use of POSSs for making polymer composites has grown exponentially since the last few years of the 20th century. In comparison with the other most commonly used fillers, POSSs possess the advantage of being molecules. Thus, this allows us to combine their nano-sized cage structures, which have dimensions that are similar to those of most polymer segments and produce a particular and exclusive chemical composition. These characteristics linked with their hybrid (inorganic–organic) nature allow researchers to modify POSS according to particular needs or original ideas, before incorporating them into polymers [2]. Figure 1. Molecular structure of the prepared and investigated POSSs In this context, our research group at the University of Catania, in collaboration with eminent researchers in the field, tested the stabilization of different polymers, synthetics or naturals, such as polyethersulfone (PES), ethylene propylene diene monomer (EPDM), polyethylene oxide (PEO), and chitosan by the incorporation of polyhedral oligomeric silsesquioxanes (POSS) molecules [3-6]. Represented in their most common form by the symbol T8 and having a diameter usually falling in the range of 1.5–3 nm, POSS molecules comprise a silicon and oxygen cage completed by organic groups that are covalently bonded with silicon atoms. Novel architectures of POSS with various organic groups were synthesized by using corner capping reaction in order to verify their polimeryzability in the presence of monomer. In this work, after a spectroscopic investigation aiming at verify that the obtained molecules have the structure for which they were designed, their thermal behavior in terms of resistance to thermal degradation were evaluated by means of thermogravimetric analysis (TGA). The obtained temperatures at 5% mass loss (T5%) were compared with each other and with those of the POSSs previously designed and studied by us. Bibliography [1] Lichtenhan, J.D., Pielichowski, K., Blanco, I. POSS-Based Polymers. Polymers 2019, 11, 1727 [2] Blanco, I. The Rediscovery of POSS: A Molecule Rather than a Filler. Polymers 2018, 10, 904. [3] Cicala, G., Blanco, I., Latteri, A., Ognibene, G., Agatino Bottino, F., Fragalà, M.E. PES/POSS Soluble Veils as Advanced Modifiers for Multifunctional Fiber Reinforced Composites. Polymers 2017, 9, 281 [4] Zaharescu, T., Blanco, I., Bottino, F.A. Antioxidant activity assisted by modified particle surface in POSS/EPDM hybrids. Appl. Surf. Sci. 2020, 509, 144702 [5] Legnani, L.; Iannazzo, D.; Pistone, A.; Celesti, C.; Giofrè, S.; Romeo, R.; Di Pietro, A.; Visalli, G.; Fresta, M.; Bottino, P.; et al. Functionalized polyhedral oligosilsesquioxane (POSS) based composites for bone tissue engineering: Synthesis, computational and biological studies. RSC Adv. 2020, 10, 11325–11334 [6] Stipanelov Vrandečić, N., Erceg, M., Andričić, B., Blanco, I., Bottino, F.A. Characterization of poly(ethylene oxide) modified with different phenyl hepta isobutyl polyhedral oligomeric silsesquioxanes. J. Therm. Anal. Calorim. 2020, 142, 1863–1875

Potatoes tubers are the raw materials of many processed food, such as cooked potatoes in hot water, baked potatoes and the most popular fried potatoes. The objective of this work was to study the impact of boiling, baking and frying on microstructure and properties of six potato varieties (Agata, Agria, Innovator, Lady Rosetta, Musica and Spunta) with different origin. Scanning Electron Microscopy revealed significant differences between varieties and tuber microstructure changes following all cooking processes. Differential Scanning Calorimeter analysis showed that the transition temperatures (ranging between 60 °C and 85 °C) and enthalpies of gelatinization (2.1 J/g–3.9 J/g) of tubers were also variety dependent. In addition, the elasticity modulus of cooked samples depended on process type and followed the order: baked potatoes > boiled > fried potatoes. In particular, baked Lady Rosetta (224.3 kPa) showed the least decrease in rigidity between thermal processes. Fried Agria and Spunta, (56.3 and 61 kPa, respectively) had the smallest value of Young's modulus. Molecular marker analyses provided a genetic fingerprinting of our varieties, allowing the identification of diagnostic markers. Innovator revealed an important genetic distance from the other varieties. Such distance corresponded to its exclusive phenotypic traits, that are known to affect thermochemical properties. The information obtained in this work may be useful to further study and associate genetic sequences with appreciable food technological traits.

We present a two-step process to obtain PMMA fibrous membranes with homogeneously in situ synthesized zinc oxide nanoparticles of defined shape and size, both on the fibers' surface and bulk. The method is based on the electrospinning of PMMA/precursor solutions and the subsequent thermally activated in situ conversion of zinc acetate to zinc oxide nanoparticles directly in the solid polymeric fibers. X-ray diffraction measurements ensure the formation of crystalline ZnO nanoparticles. Scanning and transmission electron microscopy prove that homogeneously distributed nanoparticles with two different morphologies and size distributions are obtained, depending on the area of the fibers where the nanoparticles are nucleated and on the initial precursor's content. In particular, branched nanoparticles homogeneously decorate the fibers' surface with their dimensions that range from 50 nm to 140 nm for initial precursor contents from 23 to 40 wt%, respectively. On the other hand, small spherical nanoparticles of ca. 7 nm are mainly observed in the bulk of the fibers. Unlike the branched nanoparticles, the dimensions of the spherical nanoparticles are practically unaffected by the precursor amount initially loaded. The homogeneously distributed nanoparticles both on the surface and in the bulk of the polymeric fibers, combined with the high surface area provided by the fibrous structure, result in a multifunctional material characterized by reversible UV-induced wettability and water permeability, improved thermal stability and antibacterial activity particularly promising for diverse applications such as filtration, wound management, photocatalysis, antibacterial and UV-shielding textiles.

We have designed an innovative protocol for the consolidation of waterlogged archaeological woods by using acetone mixtures of halloysite clay nanotubes and a chemically modified colophony (Rosin). Firstly, we have investigated the thermal properties of HNTs/Rosin nanocomposites, which have been prepared by means of the casting method from acetone. The HNTs content have been systematically changed in order to study the influence of the inorganic filler on the thermal stability and glass transition process of Rosin. We have observed that the thermal properties of the hybrids are affected by the specific HNTs/Rosin interactions. Then, acetone dispersions of HNTs/Rosin composites at variable filler content have been employed as consolidants for waterlogged archaeological woods. The quantitative analysis of the thermogravimetric curves have provided the amount of consolidants entrapped into the wood structure. These results have been successfully correlated to the consolidation efficiencies estimated from the analysis of the wood shrinkage volume upon drying. The attained knowledge represents the basic step to develop a green protocol for the long term protection of wooden art-works. © 2017, Springer Science+Business Media B.V.

The analysis of the recurrent characteristics of the local historic architecture is useful to develop large-scale energy analyses, regulations and financial strategies, but also to support technical guidelines for an energy improvement balanced with conservation. For this purpose, a multi-scale methodology ranging from envelope components to the urban dimension is necessary. In the research here exposed, this approach is investigated by focusing on the historic architecture of Palermo. For this heritage, the collection of thermal and hygrometric data for envelope components is combined with the examination of representative constructions, based on building stock categorization. Intended as a contribution to the overall energy analysis of the architectural heritage of Palermo, this case study shows that examining the recurrent characteristics of historic architecture in a local context may promote energy improvements compatible with the material and aesthetic conservation of historic buildings.

The current environmental and energetic crisis and the resulting regulations led to a new interest in using sustainable materials for building applications. Wood can be a material with high sustainable rates because it is recyclable, reusable and naturally renewable. Moreover, its excellent strength-to-weight ratios, thermal insulating and acoustical properties make it useful for different kinds of applications in buildings, ranging from structural beams and frames, insulating envelopes, windows, door frames, to wall and flooring materials and furniture. Although wood is commonly classified as a sustainable material, its real sustainability depends on different issues: appropriate forest management, manufacturing methods and site assembly, distance required for transportation and use of glues. Wood has also good seismic performances due to its lightweight and even if timber elements are not able to have a ductile behavior, using steel connection allows to build dissipative structure, as well platform frame and X-LAM panels systems. Insulation properties are related to low thermal conductivity values. Furthermore, wooden elements can be used to minimize sound transmission and they can be employed as sustainable materials as several Life Cycle Assessment studies demonstrate. This review paper aims to analyze the structural, thermal, acoustical and environmental properties of wooden materials for building applications; other properties such as fire resistance and durability were also taken into account. The work is completed by several tables and graphs with wood properties and by an updated and thorough reference list.

Thermal conductivity measurements play a crucial role in most areas of the applied physical sciences, thereby constantly demanding for new non-invasive methods capable of providing high-resolution spatial mapping of absolute thermal conductivities on heterogeneous samples ranging from solid-state bulk materials to low-dimensionality structures. In this work, we lay the theoretical foundations and provide the experimental demonstration of a novel method for quantitative thermal conductivity mapping at tunable ∼10-μm resolution, by non-contact infrared photo-activated thermography. Starting from Fourier’s heat transfer law, we surmise a universal dependence of the thermal response of a laser-irradiated sample on its thermal conductivity, irrespectively of density and specific heat capacity. We demonstrate such a dependence over the three conductivity decades 0.1–100 W/mK by finite-element numerical simulations, and exploit it for proof-of-principle single-point thermal conductivity measurements on both thermally thick and thermally thin reference solid samples. We exemplify the feasibility of space-resolved measurements on eighteenth-century tin organ pipe fragments, where the product of the thermal conductivity times the sample thickness, imaged at 40-μm sub-diffraction resolution, is pointed out as a relevant parameter for the non-destructive characterization of the sample conservation state. By coupling temperature maps with the extraction of thermal properties at high spatial resolution, our approach significantly expands the capability of state-of-the-art infrared imaging technology in fully capturing the compositional heterogeneity and/or functional state of the imaged materials.

An analytical overview of experimental results about the heat transfer capabilities of nanofluids is presented, using widely scattered available information from diverse literature sources. It is shown that, despite the large number of publications available about this issue, only few studies provide quantitative estimates on a complete set of experimental conditions so far and many studies are not coherent. Bearing in mind this problem, in this study a selection of the most valuable papers has been done, taking into account different points of view and hypotheses. Even if this work cannot be considered exhaustive of the complete literature in the field of nanofluids, it can be taken into account as a quick reference guide to have an overview of the different heat transfer phenomena in nanofluids and how the most important parameters (size, shape, concentration, materials etc.) influence the expected thermal performance of nanofluids. (C) 2014 Elsevier Ltd. All rights reserved.

Studies on the adsorption of biopolymers onto halloysite nanotubes (HNTs) in water were conducted. Three polymers with different charges-anionic (pectin), neutral (hydroxypropyl cellulose), and cationic (chitosan)-were chosen. The thermodynamic parameters for the adsorption of polymers onto the HNT surface were determined by isothermal titration calorimetry (ITC). The experimental data were interpreted based on a Langmuir adsorption model. The standard variations in free energy, enthalpy, and entropy of the process were obtained and discussed. Turbidimetry was used to evaluate the stability of functionalized nanoparticles in water. The ζ-potential clarified the surface charge properties of functionalized nanotubes upon polymer adsorption. The interaction of modified nanotubes with polymers led to the formation of a colloidal system with tunable stability and surface properties, which offers different perspectives on new applications of these dispersions, such as carriers for substances to be released in response to external stimuli. © 2017 American Chemical Society.

Copolyesters containing rigid aromatic units based on 4,4'-sulfonylbisphenol (bisphenol S) have been prepared by melt mixing poly(propylene terephthalate) (PPT) with an ethoxylated bisphenol S (sulfonyldiphenol). The insertion of the bisphenol units inside the polymer chain occurred quantitatively and no side reaction has been observed. The copolymers displayed good thermal stability. The main effect of copolymerization was a lowering in the degree of crystallinity and a decrease of the melting temperature with respect to PPT. On the contrary, an increment of T-g as the content of bisphenol S units increased due to the stiffening effect of the moieties deriving from bisphenol S. The Wood equation described well the correlation between T-g and composition.

The mechanical and thermal properties of multi-walled carbon nano-tubes and carbon fiber reinforced epoxy resin matrix composite patch were tested, which was prepared by the hand lay-up method. The results indicated that the imagination observed by SEM presented good resin-impregnation for both of the two kinds of composite patches, and the mechanical and thermal properties of composite patch could be effectively increased by improvement of the interface combination after adding MWCNTs. For the mechanical properties of composite patch reinforced with MWCNTs, the interlaminar shear strength, bend strength and impact-tolerance were separately increased by 3.1%, 51.66% and 60.7%; and heat-resistance obtained by DMA were shown better thermal stability.

Three cold-cured epoxy resins, specifically designed as structural adhesives for rehabilitation or renewal applications of civil infrastructures and cultural heritage, were submitted to natural and artificial weather- ing. We evaluated the variations in the thermal and me- chanical properties and color changes after an artificial treatment carried out at 70 � C and 75% relative humidity and after natural weathering, performed in two areas of South Italy, both located adjacent to the Mediterranean Sea. The variations in properties due to both natural expo- sure and artificial weathering were qualitatively similar. However, the selected artificial weathering procedure appeared excessively severe compared to the weathering that occurred after outdoor exposure. V C 2010 Wiley Periodi

The aim of this work was to investigate the aerobic biodegradation of a composite under controlled composting conditions using standard test methods. Composite was formed by poly(lactic acid) (PLA), with and without the addition of maleic anhydride (MA), acting as coupling agent, thermoplastic starch (TPS) and short natural fibre (coir). For comparison its starting materials, such as TPS and matrix (containing 75 wt% of PLA and 25 wt% of TPS), were also tested. At the end of the incubation period, TPS appeared to be the most bio-susceptible material being totally biodegraded and the matrix showed a higher level of biodegradation (higher amounts of evolved CO2) than PLA, probably due to the TPS domains preferentially attacked by microorganisms and increasing the percentage of carbon dioxide produced. Fibres seemed to play a secondary role in the process as confirmed by the slight differences in carbon dioxide produced. The compatibilised composite revealed a lower percentage of evolved CO2 than the uncompatibilised one. Finally, the degradation results were confirmed by thermal properties' changes of tested materials at different incubation times, as monitored by thermal analysis, and by the scanning electron microscopy (SEM) analyses of the compost aged samples. SEM micrographs showed the formation of patterns and cracks on the surface of the materials aged in the compost evidencing a profound loss of structure. Moreover, an extended biofilm (evident also with optical microscopy observation) was detected on the biodegraded materials, thus indicating the growth of a large number of bacteria and fungi on their surfaces.

ZnO is receiving a considerable attention for the development of novel cost-effective one-dimensional nanostructures with outstanding functional properties for applications in electronics and energy. We propose a fully-coupled thermo-mechanical-electric scheme to study the current-voltage characteristic of piezoelectric ZnO NWs under a purely vertical compressive/tensile strain. Our results confirm that the thermal transport processes deeply affect the behavior of devices for piezoelectric-piezotronic applications and provides remarkable insights into the underlying physics. © 2015 IEEE.

We compare microwave and thermal curing of DGEBA thermosets hardened with BDMA catalyzed HHPA. The glass transition temperature and (complex) dielectric constant are monitored throughout the process, for variable hardener contents and curing times.

Hybrid composites consisting of poly(L-lactide), PLLA, or blends of PLLA with a PLLA-poly(ethylene oxide) diblock copolymer (15-30 wt%), COP, as a biodegradable polymeric matrix and of bioactive α-tricalcium phosphate, α-TCP, microparticles as dispersed phase (25-40 wt-%) were prepared by melt extrusion and their thermal, mechanical and degradation behaviour was investigated. SEM analysis of surfaces broken in liquid N 2 showed a good dispersion of a-TCP in the polymer matrix. A lowering of the glass transition temperature of the polymer matrix and enhanced crystallization rates of PLLA, both from the melt and from the glassy state, were observed in the presence of COP. Ternary PLLA/COP/a-TCP composites containing about 10 wt-% of COP and 25-40 wt-% of α-TCP showed improved compressive strength and deformation at yield as compared to pure PLLA. Degradation experiments revealed that in simulated body fluid the presence of α-TCP particles promoted the formation of inorganic deposits of a poor crystalline apatitic phase on composite surfaces as compact sferoids.