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In this work, an electrochemical enzyme-linked oligonucleotide array to achieve simple and rapid multidetection of aflatoxin B1 (AFB1) is presented. The assay is based on a competitive format and disposable screen-printed cells (SPCs). Firstly, the electrodeposition of poly(aniline-anthranilic acid) copolymer (PANI-PAA) on graphite screen-printed working electrodes was performed by means of cyclic voltammetry (CV). Aflatoxin B1 conjugated with bovine serum albumin (AFB1-BSA) was then immobilized by covalent binding on PANI-PAA copolymer. After performing the affinity reaction between AFB1 and the biotinylated DNA-aptamer (apt-BIO), the solution was dropped on the modified SPCs and the competition was carried out. The biotinylated complexes formed onto the sensor surface were coupled with a streptavidin-alkaline phosphatase conjugate. 1-naphthyl phosphate was used as enzymatic substrate; the electroactive product was detected by differential pulse voltammetry (DPV). The response of the enzyme-linked oligonucleotide assay was signal-off, according to the competitive format. A dose-response curve was obtained between 0.1 ng mL−1 and 10 ng mL−1 and a limit of detection of 0.086 ng mL−1 was achieved. Finally, preliminary experiments in maize flour samples spiked with AFB1 were also performed.

The conservation and protection of ancient buildings and art-works made of stone materials, that constitute the Cultural Heritage of each Country, are very delicate tasks involving different experts and disciplines. The most common and successful method for protecting the stone-made constructions and art-works consists in applying on their surfaces protective layers of polymers having oleo-hydrophobic character. Polymer materials themselves can undergo degradation if they interact with external agents, thus reducing their protective features. The durability of the protected stones is the subject of many investigations in the last decades, but, among the agents able to severely affect the treated stone substrates outdoor exposed, only little attention has been paid so far to the effects of bird droppings, also known as guano. This work would contribute to fill this gap, assessing the effects due to bird excreta on two kinds of stone (a very porous, Lecce stone, and a more compact, Trani stone) protected with an experimental polymer coating containing SiO2 nanoparticles in comparison with two commercial protective polymer products. Color, surface hydrophobicity, water vapor permeability, and capillary water absorption were evaluated before and after exposure to pancreatin, used to simulate bird droppings. Different behaviors were observed depending on the stone porosity and the nature of the polymer coating. Good performance was obtained using the coatings with nanoparticles.

An experimental study aimed at investigating the possibility to produce a Phase Change Material (PCM) for mortars by incorporating through the “form-stable method” a thermoplastic low-melting polymer (PEG 1000) into a porous inert substrate (i.e., Lecce Stone), obtained as residue from processing stone, is reported. The viscosity of pure PEG at different temperatures was first assessed to identify an appropriate processing temperature to introduce fluid PEG into the pores of the stone. A complete (chemical, thermal and morphological) characterization was performed on the developed PCM composites, varying the impregnation times. Aerial lime-based mortars were produced with the addition of the selected experimental PCM composite, taking as comparison the mortar containing only the stone as inert aggregate. On the different mortars, mechanical tests were performed in both compression and bending mode and the thermal conductivity was measured.

Eco-sustainable, low toxic and low flammable poly-ethylene glycol (PEG) was forced into flakes of the porous Lecce stone (LS), collected as stone cutting wastes, employing a very simple cheap method, to produce a &ldquo, form-stable&rdquo, phase change material (PCM). The experimental PCM was included in mortars based on different binders (hydraulic lime, gypsum and cement) in two compositions. The main thermal and mechanical characteristics of the produced mortars were evaluated in order to assess the effects due to the incorporation of the PEG-based PCM. The mortars containing the PEG-based PCM were found to be suitable as thermal energy storage systems, still displaying the characteristics melting and crystallization peaks of PEG polymer, even if the related enthalpies measured on the mortars were appreciably reduced respect to pure PEG. The general reduction in mechanical properties (in flexural and compressive mode) measured on all the mortars, brought about by the presence of PEG-based PCM, was overcome by producing mortars possessing a greater amount of binder. The proposed LS/PEG composite can be considered, therefore, as a promising PCM system for the different mortars analyzed, provided that an optimal composition is identified for each binder.

Energy use in buildings represents more than one-third of global energy consumption and contributes to nearly one-quarter of greenhouse gases emission worldwide. The thermal comfort demand represents one of the main cause of the increased energy consumption. To guarantee a thermal indoor comfort, contributing at the same time to the energy saving, the Thermal Energy Storage (TES) methodologies have recently gained interest. These technologies involve the use of a smart material, i.e. a Phase Change Material (PCM), with the capability to absorb/release energy from/in the environment; it can be easily integrated into a building material, such as a mortar. In this work, aerial lime-based mortar with the incorporation of an eco-sustainable PCM have been analyzed with the purpose to improve the energy efficiency of buildings. For its non-toxic nature, a thermoplastic polymer has been selected as PCM, i.e. Poly-Ethylene Glycol (PEG 1000). This material was included in an inert support obtained as byproduct of stone extraction from quarry. The final product, i.e. PEG/stone, can be regarded as a composite to be used as mortar aggregate. A preliminary (chemical and physical) characterization of this compound shown that the sustainable aggregates PEG/stone have an appropriate Latent Heat Thermal Energy Storage (LHTES). The addition of these aggregates into a mortar compositions lead to an unsuitable reduction of mechanical properties.

This paper aims at reviewing the works published in the last five years (2016–2020) on polymer nanocomposites based on epoxy resins. The different nanofillers successfully added to epoxies to enhance some of their characteristics, in relation to the nature and the feature of each nanofiller, are illustrated. The organic–inorganic hybrid nanostructured epoxies are also introduced and their strong potential in many applications has been highlighted. The different methods and routes employed for the production of nanofilled/nanostructured epoxies are described. A discussion of the main properties and final performance, which comprise durability, of epoxy nanocomposites, depending on chemical nature, shape, and size of nanoparticles and on their distribution, is presented. It is also shown why an efficient uniform dispersion of the nanofillers in the epoxy matrix, along with strong interfacial interactions with the polymeric network, will guarantee the success of the application for which the nanocomposite is proposed. The mechanisms yielding to the improved properties in comparison to the neat polymer are illustrated. The most important applications in which these new materials can better exploit their uniqueness are finally presented, also evidencing the aspects that limit a wider diffusion.

The use of fiber reinforced polymer (FRP) composites for the rehabilitation of buildings or other infrastructure is increasingly becoming an effective and popular solution, being able to overcome some of the drawbacks experienced with traditional interventions and/or traditional materials. The knowledge of long-term performance and of durability behavior of FRP, in terms of their degradation/aging causes and mechanisms taking place in common as well as in harsh environmental conditions, still represents a critical issue for a safe and advantageous implementation of such advanced materials. The research of new and better performing materials in such fields is somewhat limited by practical and economical constrains and, as a matter of fact, is confined to an academic argument.